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MVH4000D Series Datasheet

Rev. 0.98

APPLICATIONS

The MVH4000D series is ideal for use in environmental sensing for consumer electronics, automotive, industrial,

agricultural, and other sectors. Some application examples include:

FEATURES

● Fast RH response time

Typical 4 seconds time constant

● High accuracy

Relative humidity (MVH4001D): Typical: ±1.5% RH

Temperature (MVH4001D): Typical: 0.2°C

● Independent resolution settings for RH and T

8, 10, 12 or 14 bits

● Fully compliant I2C interface

● Extended supply voltage range of 1.71V – 3.6V

● Very low power consumption

0.3 μA avg. current at one temperature meas.

per second (8-bit res., 3.3V supply)

● Small form factor for use in compact systems

2.5 x 2.5 x 0.9 mm DFN-style LGA package

USER BENEFITS

● Long Term Stability and Reliability:

Proprietary sensing structures and protection

technology, robust biasing circuitry, and self-

diagnosis algorithms ensure accurate and

repeatable measurements.

● Digital Output:

Allows for native interfacing with embedded system

components such as FPGAs or off-the-shelf

microcontrollers.

● Fully Calibrated System:

Built-in digital sensor calibration ensures high

accuracy measurements and linear behavior under

varying sensing environments.

MVH4000D Series

High Performance Digital Relative Humidity & Temperature Sensor

GENERAL DESCRIPTION

[Patents protected & patents pending]

MEMS Vision’s relative humidity (RH) and temperature (T) sensors are built by combining the company’s

revolutionary MoSiC® technology with its extensive ASIC design experience. This combination enables high levels of

performance, such as fast RH measurement response time and high accuracy.

The technology also offers a very robust proprietary sensor-level protection, ensuring excellent stability against

aging and harsh environmental conditions such as shock and volatile chemicals.

The highly miniaturized smart sensors are fully calibrated and provide standard digital I2C outputs to enable plug-

and-play integration. The output RH & T resolutions can be independently programmed for maximum flexibility and

to minimize power consumption, depending on the application and operating conditions.

The micro-Watt levels of power consumption of these sensors make them the ideal choice for portable and

remote applications.

MEMS Vision’s combined RH/T sensors offer the industry’s most competitive performance-to-price value, for a

wide range of applications and end users.

●OEM products

●Instrumentation

●Medical equipment

●White goods

●Battery-powered systems

●Drying

●Meteorology

●Refrigeration equipment

●Smartphones and tablets

●HVAC systems

●Building automation

●Data logging

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MVH4000D Series Datasheet

Rev. 0.98

Table Of Contents

1 Pin Configuration ............................................................................................................................................................. 5

2 Pin Assignment and Application Circuit ................................................................................................................ 5

3 Functional Description .................................................................................................................................................. 5

4 Chip Performance Summary ...................................................................................................................................... 7

5 Relative Humidity and Temperature Tolerances ............................................................................................ 9

5.1 Accuracy Tolerances ............................................................................................................................................ 9

5.2 Normal Operating Conditions ....................................................................................................................... 10

6 User Guide ......................................................................................................................................................................... 11

6.1 Sensor Communications ................................................................................................................................... 11

6.2 Performing Measurements with the MVH4000D Series Sensors ............................................... 12

6.2.1 Performing a Hold Measurement ........................................................................................................... 13

6.2.2 Performing a No-Hold Measurement ................................................................................................... 13

6.2.3 Interpreting the Data .............................................................................................................................. 14

6.2.4 Measurement Conversion Times ....................................................................................................... 15

6.2.5 CRC Checksum Calculation ................................................................................................................... 15

6.3 Periodic Measurement Mode ....................................................................................................................... 16

6.4 Alert Feature .......................................................................................................................................................... 17

6.4.1 Alert Pin – Measurement Active ............................................................................................................. 17

6.4.2 Alert Pin – Humidity / Temperature Threshold Detection .................................................... 17

6.5 Accessing Configurable Sensor Registers ............................................................................................... 19

6.5.1 Read Register Command ........................................................................................................................... 19

6.5.2 Write Register Command ...................................................................................................................... 20

6.6 Configuration Bits ................................................................................................................................................ 21

6.6.1 Setting the Measurement Resolution .................................................................................................. 21

6.6.2 Periodic Measurement Settings ......................................................................................................... 21

6.6.3 Alert Feature Settings ............................................................................................................................ 22

6.7 Reading the Sensor ID Number ................................................................................................................... 24

6.8 I2C Timing Specifications ................................................................................................................................. 26

7 Package and PCB Information ................................................................................................................................ 27

7.1 Package Drawing .................................................................................................................................................. 27

7.2 Tape and Reel Information ............................................................................................................................ 28

7.3 Soldering Information ....................................................................................................................................... 28

7.4 PCB Layout Considerations ............................................................................................................................ 29

8 Storage and Handling Information ....................................................................................................................... 29

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MVH4000D Series Datasheet

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List Of Tables

Table 1: Pin Assignment. ........................................................................................................................................................ 5

Table 2: MVH4000D Series Specifications. ................................................................................................................... 7

Table 3: Commands Code and Description. ................................................................................................................. 12

Table 4: Measurement Command Modes. ................................................................................................................... 12

Table 5: Conversion Times. ................................................................................................................................................ 15

Table 6: CRC Checksum Properties. .............................................................................................................................. 15

Table 7: Alert status bits. .................................................................................................................................................... 18

Table 8: Temperature and Humidity Measurement Resolution Settings. ................................................... 21

Table 9: Periodic Measurement Settings. ................................................................................................................... 21

Table 10: Alert Feature Settings. .................................................................................................................................... 22

Table 11: I2C Timing Parameters. ..................................................................................................................................... 26

List Of Figures

Fig. 1: Diagram of pin configuration (top view). .......................................................................................................... 5

Fig. 2: DFN-style LGA package. ............................................................................................................................................ 5

Fig. 3: Application Circuit. ....................................................................................................................................................... 5

Fig. 4: MVH4000D series functional diagram. ............................................................................................................ 6

Fig. 4: Relative humidity and temperature tolerances (RH tolerances given at TA = +25

C). ............. 9

Fig. 5: Relative humidity tolerances across temperature. .................................................................................. 10

Fig. 6: Diagram of an I2C interconnect with one master and three slave devices. .................................. 11

Fig. 7: I2C bus start and stop conditions. ....................................................................................................................... 11

Fig. 8: Typical hold measurement sequence for a humidity and temperature command. .................. 13

Fig. 9: Typical no-hold measurement sequence for a humidity and temperature command. .......... 14

Fig. 10: Sequence to retrieve the latest results in periodic measurement mode. ................................. 16

Fig. 11: Sequence to stop periodic measurements. ................................................................................................ 16

Fig. 12: Alert Pin Functionality – Measurement Active Indicator. .................................................................... 17

Fig. 13: Example of Alert Pin Functionality in Humidity / Temperature Detection Mode. ................. 18

Fig. 14: Data returned from MVH4000D chip when the Alert feature is enabled in Periodic

Measurement Mode. ..................................................................................................................................................... 19

Fig. 15: Read Register command sequence. .............................................................................................................. 20

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MVH4000D Series Datasheet

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Fig. 16: Write Register command sequence. ............................................................................................................. 20

Fig. 17: Read Sensor ID command sequence. ............................................................................................................ 25

Fig. 18: I2C timing diagram. ................................................................................................................................................ 26

Fig. 19: LGA package drawing. ............................................................................................................................................ 27

Fig. 20: LGA package land pattern (top view). ........................................................................................................... 27

Fig. 21: Packaging tape drawing. ...................................................................................................................................... 28

Fig. 22: Recommended lead-free soldering profile ................................................................................................ 28

Fig. 23: Thermal isolation of sensor using milled PCB openings. .................................................................... 29

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MVH4000D Series Datasheet

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1 Pin Configuration

Fig. 1: Diagram of pin configuration (top view).

Fig. 2: DFN-style LGA package.

2 Pin Assignment and Application Circuit

Table 1: Pin Assignment.

Name

Function

SDA1

I2C data

No connect

ALERT

Digital output indicating an alarm

condition. Leave floating if unused.

SCL1

I2C clock (up to 400 kHz)

VDD

Positive supply

No connect

VSS

Negative supply or ground

1Requires a 2.2 kW pull-up resistor.

Fig. 3: Application Circuit.

3 Functional Description

The MVH4000D series sensors are highly integrated digital devices that accurately measure relative humidity and

temperature levels.

An analog-to-digital converter (ADC) with a configurable resolution is interfaced with an analog multiplexer and

two sensors in order to allow for the measurement of both relative humidity and temperature. High precision

biasing and clock generation ensures stable operation over a wide temperature range. The sensor can be used to

measure the ambient relative humidity and temperature in real-time or be used for data-logging, and can

interface with any I2C compliant system for digital transmission of the acquired data.

Calibration data and compensation logic are integrated within the system, such that the chip does not require any

user calibration, and is readily compensated for accurate operation over a wide range of temperature and

humidity levels.

SCL SDANC

VDD VSSNC

1234

8765

ALERT

0.1µF

master

2.2kΩ

ALERT

SCL VDD

VSSSDA

master

MVH4000D

MCU

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MVH4000D Series Datasheet

Rev. 0.98

Fig. 4: MVH4000D series functional diagram.

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MVH4000D Series Datasheet

Rev. 0.98

4 Chip Performance Summary

Table 2: MVH4000D Series Specifications.

At TA = +25°C, VDD = +1.71 V to +3.6 V unless otherwise noted.

PARAMETER

CONDITION

MIN

TYP

MAX

UNITS

RELATIVE HUMIDITY SENSOR

Range

100

%RH

Accuracy Tolerance2

MVH4001D

10% to 90% RH

±1.5

±1.8

%RH

MVH4002D

±2.0

±2.3

MVH4003D

20% to 80% RH

±2.5

±3.5

MVH4004D

±3.5

±4.5

Resolution

14 bits

0.04

0.05

%RH

Hysteresis

±1.0

%RH

Non-Linearity from

Response Curve

MVH4001D

10% to 90% RH

±0.15

±0.25

%RH

MVH4002D

±0.15

±0.25

MVH4003D

20% to 80% RH

±0.15

±0.25

MVH4004D

±0.15

±0.25

Long-term Stability

0.1

0.25

%RH/yr

Response Time Constant3 (tH)

20% to 80% RH

Still air

3.0

4.0

6.0

sec.

TEMPERATURE SENSOR

Range

-40

125

°C

Accuracy Tolerance4

MVH4001D

-10ºC to 80ºC

±0.2

±0.3

°C

MVH4002D

±0.2

±0.3

MVH4003D

0ºC to 70ºC

±0.25

±0.35

MVH4004D

±0.3

±0.5

Resolution

14 bits

0.01

0.02

°C

Response Time Constant5 (tT)

> 2

sec.

Long-term Stability

0.03

°C/yr

Supply Voltage Dependency

0.03

0.1

°C/V

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MVH4000D Series Datasheet

Rev. 0.98

Table 2 (cont’d): MVH4000D Series Specifications

PARAMETER

CONDITION

MIN

TYP

MAX

UNITS

CHIP TEMPERATURE RANGE

Operating Range

-40

125

°C

Recommended Storage Range

°C

Storage Range

-40

125

°C

MEASUREMENT TIME

8 bits Resolution

Temperature and

Humidity

(Including digital

compensation)

0.64

10 bits Resolution

0.80

12 bits Resolution

1.04

14 bits Resolution

1.70

SLEEP MODE

Sleep Current

ISD

25°C

0.010

0.025

µA

-40°C to 125°C

2.5

µA

POWER SUPPLY

Operating Supply Voltage

VDD

1.71

3.3

3.6

SUPPLY CURRENT

Average Current

(VDD = 3.3V)

8 bits resolution

one RH + T meas./s

0.27

0.30

0.32

µA

10 bits resolution

one RH + T meas./s

0.31

0.34

0.37

12 bits resolution

one RH + T meas./s

0.39

0.43

0.47

14 bits resolution

one RH + T meas./s

0.55

0.62

0.69

2For monotonic increases in the range of 10% to 90% RH after the sensor has been stabilized at 50% RH. See Fig. 4 and Fig. 5 for more

details.

3From initial value to 63% of the total variation.

4See Fig. 4 for more details.

5Response time depends on system thermal mass (e.g., PCB dimensions and thickness) and airflow.

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MVH4000D Series Datasheet

Rev. 0.98

5 Relative Humidity and Temperature Tolerances

5.1 Accuracy Tolerances

The typical and maximum relative humidity and temperature accuracy tolerances for the MVH4000D series

sensors are shown in Fig. 4.

MVH4001D

MVH4002D

MVH4003D

MVH4004D

Fig. 4: Relative humidity and temperature tolerances (RH tolerances given at TA = +25

C).

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MVH4000D Series Datasheet

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The typical relative humidity accuracy across temperature is shown in Fig. 5.

MVH4001D

MVH4002D

MVH4003D

MVH4004D

Fig. 5: Relative humidity tolerances across temperature.

5.2 Normal Operating Conditions

The sensor has been optimized to perform best in the more common temperature and humidity ranges of 10°C to

50°C and 20% RH to 80% RH (non-condensing), respectively. If operated outside of these conditions for extended

periods of time, especially at high humidity levels, the sensors may exhibit an offset. In most cases, this offset is

temporary and will gradually disappear once the sensor is returned to normal temperature and humidity

conditions. The amount of the shift and the duration of the offset vary depending on the duration of exposure

and the severity of the relative humidity and temperature conditions. The time needed for the offset to disappear

can be decreased by using the procedure described in Section 8 of this datasheet.

Temperature (°C)

Rel. Humidity (%RH)

±2.0

±2.5

±3.0

±2.0

±1.5

±2.0

MVH3201D - Typical RH Accuracy over Temperature

Temperature (°C)

Rel. Humidity (%RH)

±2.7

±3.2

±2.7

±2.0

±2.7

MVH3202D - Typical RH Accuracy over Temperature

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MVH4000D Series Datasheet

Rev. 0.98

6 User Guide

6.1 Sensor Communications

The MVH4000D series sensors communicate using the Inter-IC (I2C) standard bus protocol. To accommodate

multiple devices, the protocol uses two bi-directional open-drain lines: a Serial Data Line (SDA) and a Serial Clock

Line (SCL). Because these are open-drain lines, pull-up resistors to VDD must be provided as shown in Fig. 6. Several

slave devices can share the I2C bus, but only one master device can be present on the line.

Fig. 6: Diagram of an I2C interconnect with one master and three slave devices.

Each transmission is initiated when the master sends a ‘0’ start bit (S), and the transmission is terminated when

the master sends a ‘1’ stop bit (P). These bits are exclusively transmitted while the SCL line is high. The

waveforms corresponding to these conditions are illustrated in Fig. 7.

Fig. 7: I2C bus start and stop conditions.

Once the start condition has been sent, the SCL line is toggled at the prescribed data-rate, clocking subsequent

data transfers. Data on the SDA line is always sampled on the rising edge of the SCL line and must remain stable

while SCL is high to prevent false Start or Stop conditions (see Fig. 7).

Following the start bit, address bits select the device targeted for communications and a read/write bit indicates

the transfer direction of any subsequent data. The master sends the unique 7-bit address of the desired device

and a read/write bit set to ‘1’ to indicate a read from slave to master or to ‘0’ to indicate a write from master to

slave. All transfers consist of eight data bits and one response bit set to ‘0’ for Acknowledge (ACK) or ‘1’ for Not

Acknowledge (NACK). After the acknowledge signal is received another data byte can be transferred, or the

communication can be stopped with a stop bit.

An MVH4000D series sensor operates as a slave on the I2C bus and supports data rates of up to 400 kHz in

accordance with the I2C protocol. The default address of the sensor is 0x54. Custom I2C addresses can be provided

upon request (please contact support@mems-vision.com for details). The sensor can be interfaced with any I2C

master such as a microcontroller, and the master is responsible for generating the SCL signal for all

communications with the MVH4000D series sensor.

The official I2C-bus specification and user manual documentation can be found at:

https://www.nxp.com/docs/en/user-guide/UM10204.pdf

Master

Slave 1 Slave 2 Slave 3

SCL

SDA

VDD

Pull-up

resistors

SCL

SDA

SCL

SDA

Start Condition Stop Condition

StopStart

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MVH4000D Series Datasheet

Rev. 0.98

The MVH4000D series sensors are equipped with different commands to configure the chip and to perform

measurement as described in Table 3.

Table 3: Commands Code and Description.

Command Code (HEX)

Description

0xE3

Hold Temperature Measurement

0xF3

No-hold Temperature Measurement

0xE5

Hold Humidity and Temperature Measurement

0xF5

No-hold Humidity and Temperature Measurement

0xA7

Read Register

0xA6

Write Register

0x30

Stop Periodic Measurements

0xD7

Read Sensor ID

The Hold and No-hold commands will be described in Section 6.2, and the read and write register commands will be

described in Section 6.5. The MVH4000D sensor can measure only temperature or both humidity and temperature

as described in Table 4. Both options return fully calibrated measurements that can be converted to humidity and

temperature readings using the equations in Section 6.2.3.

Table 4: Measurement Command Modes.

Measurement

Command Mode

Description

Number of data

bytes sent on the

I2C bus

Temperature

The chip only measures temperature and sends the 14-bit

result once the measurement is complete.

2 bytes + 1 byte CRC

Humidity and

Temperature

The chip measures humidity and temperature and sends the

14-bit humidity result followed by the 14-bit temperature

result once the measurement is complete.

4 bytes + 1 byte CRC

6.2 Performing Measurements with the MVH4000D Series Sensors

There are two types of measurement commands:

1. Hold measurement commands: The MVH4000D series sensor holds the SCL line low during the

measurement and releases the SCL line when the measurement is complete. This lets the master

know exactly when the measurement has finished. Using this mode will prevent the master from

communicating with any other slave until the measurement is complete. Note that the minimum

frequency for the SCL clock in this mode is 200 kHz.

2. No-hold measurement commands: The MVH4000D series sensor does not hold the SCL line low, and

the master is free to initiate communication with other slaves while the chip is performing the

measurement. To obtain the measurement data, the master must request the result from the chip

after the expected conversion time which depends on the measurement resolution as summarized in

Section 6.2.4. There is no minimum clock frequency when in this mode.

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MVH4000D Series Datasheet

Rev. 0.98

6.2.1 Performing a Hold Measurement

A hold measurement sequence consists of the following steps, as illustrated in Fig. 8.

Wake up the MVH4000D series sensor from sleep mode by sending its I2C address with a write bit,

and initiate a measurement by sending the desired hold measurement command.

Change the direction of communication by sending a start bit, the MVH4000D I2C address, and a read

bit. The SCL line is held low by the sensor during the measurement process, which prevents the

master from initiating any communications with other slaves on the bus.

Once the requested measurement is completed by the MVH4000D series sensor, the SCL line is

released and the chip waits for the SCL clock signal to send the results. The sensor will then transmit

the requested measurement data on the bus for the master to capture.

Fig. 8: Typical hold measurement sequence for a humidity and temperature command.

6.2.2 Performing a No-Hold Measurement

A no-hold measurement sequence consists of the following steps, as illustrated in Fig. 9.

1. Wake up the MVH4000D series sensor from sleep mode by sending its I2C address with a write bit, and

initiate a measurement by sending the desired no-hold measurement command.

2. To read the result from the MVH4000D series sensor, the master has to send the chip its I2C address

and a read bit. If the measurement is completed and the result is ready, the chip will send an ACK bit

and starts to send the result over the bus. If the measurement is still in progress, the chip will send a

NACK bit and the master will need to try to read the result again.

S1 0 1 0 1 0 0 0 ACK 1 1 1 0 0 1 0 1 ACK

S1 0 1 0 1 0 0 1 ACK

NACK P

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 ACK

1 1 1 1 0 0 1 0 NACK P

S P

Step 3 :

I2C Address (7 bits) + write bit

Measurement Command (0xE5)

I2C Address (7 bits) + read bit

The SCL line is held low

Step 1 :

Step 2 :

Temperature Data [7:0]

Bits generated by the MVH4000D chip

Humidity Data [7:0]

CRC

Humidity Data [13:8]

0's

Temperature Data [13:8]

Stop Sequence

Start Sequence

Bits generated by the master

The master can stop the data transmission at any point if the

rest of the data is not needed.

The MVH4000D chip

starts measuring

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MVH4000D Series Datasheet

Rev. 0.98

Fig. 9: Typical no-hold measurement sequence for a humidity and temperature command.

6.2.3 Interpreting the Data

As stated in Table 4, the measurement data can either be two or four bytes long depending on whether a

temperature measurement or a humidity and temperature measurement was initiated. The most significant bit of

the reading is sent first followed by the least significant bits. The humidity and temperature measurements are

always scaled up to a 14-bit value regardless of the selected resolution of the sensor. The relative humidity (in

percent) and the temperature (in degrees Celsius) are obtained as follows:

𝐻𝑢𝑚𝑖𝑑𝑖𝑡𝑦([%𝑅𝐻]= ( !"#$%$&'[)*:,]

.!"/) ∗100 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒([°𝐶]= ( 01#2134&"315[)*:,]

.!"/) ∗165 −40

S1 0 1 0 1 0 0 0 ACK 1 1 1 1 0 1 0 1 ACK P

S1 0 1 0 1 0 0 1 NACK

S1 0 1 0 1 0 0 1 ACK

NACK P

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 ACK

1 1 1 1 0 0 1 0 NACK P

S P

I2C Address (7 bits) + write bit

The master can stop the data transmission at any point if the

rest of the data is not needed.

Temperature Data [7:0]

Bits generated by the MVH4000D chip

Humidity Data [7:0]

CRC

Bits generated by the master

0's

Step 1 :

Measurement Command (0xF5)

Humidity Data [13:8]

0's

Temperature Data [13:8]

The MVH4000D chip replies with ACK if the

result is ready then starts to send the result

The MVH4000D chip replies with NACK if

the result is not ready

Start Sequence

Stop Sequence

I2C Address (7 bits) + read bit

Step 2:

The MVH4000D

chip starts

measuring here

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MVH4000D Series Datasheet

Rev. 0.98

6.2.4 Measurement Conversion Times

The MVH4000D series sensors are designed to have relatively fast conversion times. The conversion time depends

on the resolution of the measurement and the command type (temperature or humidity and temperature).

Table 5 summarizes the conversion times for different resolutions.

Table 5: Conversion Times.

Measurement

Resolution

(bits)

Measurement

Time (ms)

Temperature

0.37

0.45

0.60

0.91

Humidity and

Temperature1

0.64

0.80

1.04

1.70

1 Assuming the same resolution settings for both humidity and temperature measurements.

6.2.5 CRC Checksum Calculation

An 8-bit CRC checksum is transmitted after each measurement so the user can check for data corruption during

communications if desired. The properties of the CRC algorithm used are summarized in Table 6, and the CRC is

based on all 4 bytes of measurement data (2 bytes of humidity data followed by 2 bytes of temperature data). For

temperature-only measurements, the 2 bytes of humidity data are set to be all 0’s for the CRC calculation.

Table 6: CRC Checksum Properties.

Property

Value

Input Data Width

32 bits

CRC Width

8 bits

Polynomial

0x1D (x8 + x4 + x3 + x2 + 1)

Initial Value

0xFF

Final XOR Value

0x00

Reflect Input

Reflect Output

Example

CRC (0x05800580) = 0xF2

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MVH4000D Series Datasheet

Rev. 0.98

6.3 Periodic Measurement Mode

The MVH4000D sensors can also be configured to measure at regular intervals without user intervention, and the

process to enable this mode is described in Section 6.6.2. In this mode, the user can read the latest relative

humidity / temperature data by issuing a data fetch sequence, which consists of sending the MVH4000D I2C

address with a read bit. The sensor will then send the latest measurement result over the I2C bus. The data fetch

sequence is illustrated in Fig. 10.

Fig. 10: Sequence to retrieve the latest results in periodic measurement mode.

The frequency of the periodic measurements can be set using the configuration registers. Section 6.5 describes

how these registers are accessed, and Section 6.6.2 provides the register settings needed to configure and

activate the periodic measurements.

When the periodic measurement mode is active, the only commands the chip will respond to are the data fetch

command, and a command to stop the periodic measurements. The command to stop periodic measurements is

issued by sending the I2C address with a write bit, followed by the command 0x30, as shown in Fig. 11. Once the

periodic measurements have been stopped, the chip returns to sleep and is ready to accept all valid I2C commands.

Fig. 11: Sequence to stop periodic measurements.

S1 0 1 0 1 0 0 1 ACK

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 ACK

1 1 1 1 0 0 1 0 NACK P

S P

CRC

Start Sequence

Stop Sequence

Bits generated by the master

Bits generated by the MVH4000D chip

Humidity Data [7:0]

Temperature Data [7:0]

0's

Humidity Data [13:8]

0's

Temperature Data [13:8]

Step 2:

Step 1 :

I2C Address (7 bits) + read bit

The MVH4000D chip responds with an ACK

and then starts to send the latest result

S1 0 1 0 1 0 0 0 ACK 0 0 1 1 0 0 0 0 ACK P

I2C Address (7 bits) + write bit

Stop Periodic Meas. Command (0x30)

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MVH4000D Series Datasheet

Rev. 0.98

6.4 Alert Feature

The MVH4000D has an optional Alert feature that can be configured in two ways as follows:

1. The Alert pin can be used to indicate when a measurement is active in Periodic Measurement Mode. This

is the default behavior of the Alert pin upon power-up.

2. The Alert pin can be used to trigger an interrupt on the system microcontroller so an appropriate action

can be taken if the temperature or humidity is outside of the desired limits.

These features will be described in the following two sub-sections.

6.4.1 Alert Pin – Measurement Active

The default behavior of the Alert pin is to indicate when a measurement is active if Periodic Measurement Mode is

used. Upon power-up, the Alert pin will have a logic high level. When periodic measurement mode is activated, the

Alert pin will have a logic low level between measurements, and a logic high during measurements. This behavior

is shown in Fig. 12, and the Alert pin will exhibit this functionality when the temperature and humidity alerts are

disabled (see Table 10).

If Periodic Measurement Mode is not active, the Alert pin will remain at a logic high level.

Fig. 12: Alert Pin Functionality – Measurement Active Indicator.

6.4.2 Alert Pin – Humidity / Temperature Threshold Detection

The Alert pin can also be configured to send a signal when a humidity / temperature threshold is exceeded, and

the system needs to take action. In this mode, the Alert feature has a programmable threshold, polarity, and

hysteresis, and can apply to both temperature and humidity measurements. An example of the functionality of

the Alert feature can be seen in Fig. 13.

State

of Alert

pin at

power-

Periodic

Measurement

Mode Activated

Measurement in Progress

18/30

MVH4000D Series Datasheet

Rev. 0.98

Fig. 13: Example of Alert Pin Functionality in Humidity / Temperature Detection Mode.

The registers used to enable the Alert feature and the temperature / humidity thresholds are shown in Table 10.

When the Alert feature is enabled for either humidity or temperature in Periodic Measurement Mode, an

additional status byte will precede the measurement values. The format of the bits returned from the MVH4000D

sensor when any Alert is enabled during Periodic Measurement Mode is shown in Fig. 14, and the meaning of the

Alert status bits are defined in Table 7.

Table 7: Alert status bits.

Status Bit

Meaning

High (0b1) if the Temperature High Alert is triggered

High (0b1) if the Temperature Low Alert is triggered

High (0b1) if the Humidity High Alert is triggered

High (0b1) if the Humidity Low Alert is triggered

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MVH4000D Series Datasheet

Rev. 0.98

Fig. 14: Data returned from MVH4000D chip when the Alert feature is enabled in Periodic Measurement

Mode.

6.5 Accessing Configurable Sensor Registers

The MVH4000D measurement settings can be changed by accessing the appropriate configuration registers and

altering their values. This can be done by issuing a Write Register command. A Read Register command is also

available to read the configuration register values. These commands will be described in this section, and the

configuration registers and settings will be described in Section 6.6.

While accessing specific configuration bits in any register, all the other bits in that register must be left unchanged.

To write a specific bit/bits in a register, the process is as follows:

1. Read the entire configuration register using the sequence described in Section 6.5.1.

2. Mask the register such that only the required bits are changed, according to the configuration parameters

in Section 6.6.

3. Write the new register back to the appropriate address using the Write Register command sequence

described in Section 6.5.2.

All configuration registers will be reset to their default values if the power supply to the chip is cutoff.

6.5.1 Read Register Command

A Read Register sequence consists of the following steps, as illustrated in Fig. 15.

1. Wake up the MVH4000D series sensor from sleep mode by sending its I2C address with a write bit, and

initiate a Read Register command by sending the command 0xA7.

2. Send the address of the register to be read.

3. Change the direction of communication by sending the MVH4000D I2C address and a read bit. The chip will

send the data stored in this register, after which the master replies with a NACK and a STOP bit.

X X X X TH TL HH HL ACK

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 ACK

1 1 1 1 0 0 1 0 NACK P

S P

Bits generated by the master

Bits generated by the MVH4000D chip

Don't Care

Alert Status

0's

Humidity Data [13:8]

Humidity Data [7:0]

0's

Temperature Data [13:8]

Temperature Data [7:0]

CRC

Start Sequence

Stop Sequence

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MVH4000D Series Datasheet

Rev. 0.98

Fig. 15: Read Register command sequence.

6.5.2 Write Register Command

A Write Register sequence consists of the following steps, as illustrated in Fig. 16.

1. Wake up the MVH4000D series sensor from sleep mode by sending its I2C address with a write bit, and

initiate a Write Register command by sending the command 0xA6.

2. Send the address of the register to write.

3. Send the data to be stored in this register followed by a STOP bit.

Fig. 16: Write Register command sequence.

S1 0 1 0 1 0 0 0 ACK 1 0 1 0 0 1 1 1 ACK

0 0 0 0 0 0 0 0 ACK

S1 0 1 0 1 0 0 1 ACK 0 0 1 0 1 1 1 1 NACK P

S P

Stop Sequence

Bits generated by the master

Bits generated by the MVH4000D chip

Start Sequence

Step 3 :

Step 1 :

Step 2 :

I2C Address (7 bits) + write bit

Read Register Command (0xA7)

I2C Address (7 bits) + read bit

S1 0 1 0 1 0 0 0 ACK 1 0 1 0 0 1 1 0 ACK

0 0 0 0 0 0 0 0 ACK

0 0 1 0 1 0 1 0 ACK P

S P

Bits generated by the master

I2C Address (7 bits) + write bit

Write Register Command (0xA6)

Data to be saved in the register

Start Sequence

Stop Sequence

Bits generated by the MVH4000D chip

Step 3 :

Step 1 :

Step 2 :

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MVH4000D Series Datasheet

Rev. 0.98

6.6 Configuration Bits

6.6.1 Setting the Measurement Resolution

The chip can be configured to perform measurements at different humidity and temperature resolutions by using

the Read and Write Register commands with the appropriate register address. There are four separate resolution

settings for the temperature and humidity measurements, as summarized in Table 8.

Table 8: Temperature and Humidity Measurement Resolution Settings.

Setting

(HEX)

Bits

Description

Resolution for

temperature

measurement

0x00

<1:0>

0b00 for 8 bits

0b01 for 10 bits

0b10 for 12 bits

0b11 for 14 bits

Resolution for

humidity

measurement

0x00

<3:2>

0b00 for 8 bits

0b01 for 10 bits

0b10 for 12 bits

0b11 for 14 bits

6.6.2 Periodic Measurement Settings

The registers that are used to activate and configure the periodic measurement settings are shown in Table 9.

Table 9: Periodic Measurement Settings.

Setting

(HEX)

Bits

Description

Activate Periodic

Measurements

0x02

<7>

0b0 when periodic measurements are deactivated

0b1 to activate periodic measurements

Frequency of

Periodic

Measurements

0x02

<5:4>

0b00 for a measurement every 0.5 s

0b01 for a measurement every 1 s

0b10 for a measurement every 2.5 s

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MVH4000D Series Datasheet

Rev. 0.98

6.6.3 Alert Feature Settings

Table 10: Alert Feature Settings.

Setting

Address

(HEX)

Bits

Description

Alert Pin Polarity in

Humidity /

Temperature

Threshold

Detection Mode

0x02

<0>

0b0 Alert pin is active high when triggered

0b1 Alert pin is active low when triggered

Alert Enable

Settings

0x03

<3:0>

Enable the Alert feature when thresholds are surpassed as

follows:

Bit <0>: RH Low alert enable

Bit <1>: RH High alert enable

Bit <2>: Temperature Low alert enable

Bit <3>: Temperature High alert enable

Setting a bit to 0b1 means this specific alert condition is

enabled, and setting a bit to 0b0 means this specific alert

condition is disabled.

Trigger Threshold

for Temperature

High Alert

0x08, 0x07

<13:0>

Registers 0x08, 0x07 set the threshold for when the

“Temperature High” alert is triggered. When the measured

temperature goes above the value in this register, the Alert pin

will be triggered.

The temperature used for the threshold is composed of 14-bits

as follows:

This 14-bit value is converted into a temperature threshold

using the same conversion equation shown in Section 6.2.3.

Reset Threshold

for Temperature

High Alert

0x06, 0x05

<13:0>

Registers 0x06, 0x05 set the threshold for when the

“Temperature High” alert condition is reset. After the alert is

triggered, it will only be reset after the measured temperature

goes below the value in this register.

The temperature used for the threshold is composed of 14-bits

as follows:

This 14-bit value is converted into a temperature threshold

using the same conversion equation shown in Section 6.2.3.

0000010110000000

0's

Trigger Threshold [13:8]

Trigger Threshold [7:0]

0000010110000000

0's

Reset Threshold [13:8]

Reset Threshold [7:0]

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MVH4000D Series Datasheet

Rev. 0.98

Trigger Threshold

for Temperature

Low Alert

0x0A, 0x09

<13:0>

Registers 0x0A, 0x09 set the threshold for when the

“Temperature Low” alert is triggered. When the measured

temperature goes below the value in this register, the Alert pin

will be triggered.

The temperature used for the threshold is composed of 14-bits

as follows:

This 14-bit value is converted into a temperature threshold

using the same conversion equation shown in Section 6.2.3.

Reset Threshold

for Temperature

Low Alert

0x0C, 0x0B

<13:0>

Registers 0x0C, 0x0B set the threshold for when the

“Temperature Low” alert condition is reset. After the alert is

triggered, it will only be reset after the measured temperature

goes above the value in this register.

The temperature used for the threshold is composed of 14-bits

as follows:

This 14-bit value is converted into a temperature threshold

using the same conversion equation shown in Section 6.2.3.

Trigger Threshold

for Relative

Humidity High Alert

0x10, 0x0F

<13:0>

Registers 0x10, 0x0F set the threshold for when the “RH High”

alert is triggered. When the measured RH goes above the value

in this register, the Alert pin will be triggered.

The humidity used for the threshold is composed of 14-bits as

follows:

This 14-bit value is converted into a humidity threshold using

the same conversion equation shown in Section 6.2.3.

Reset Threshold

for Relative

Humidity High Alert

0x0E, 0x0D

<13:0>

Registers 0x0E, 0x0D set the threshold for when the “RH High”

alert condition is reset. After the alert is triggered, it will only

be reset after the measured RH goes below the value in this

The humidity used for the threshold is composed of 14-bits as

follows:

This 14-bit value is converted into a humidity threshold using

the same conversion equation shown in Section 6.2.3.

0000010110000000

0's

Trigger Threshold [13:8]

Trigger Threshold [7:0]

0000010110000000

0's

Reset Threshold [13:8]

Reset Threshold [7:0]

0000010110000000

0's

Trigger Threshold [13:8]

Trigger Threshold [7:0]

0000010110000000

0's

Reset Threshold [13:8]

Reset Threshold [7:0]

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MVH4000D Series Datasheet

Rev. 0.98

Trigger Threshold

for Relative

Humidity Low Alert

0x12, 0x11

<13:0>

Registers 0x12, 0x11 set the threshold for when the “RH Low”

alert is triggered. When the measured RH goes below the value

in this register, the Alert pin will be triggered.

The humidity used for the threshold is composed of 14-bits as

follows:

This 14-bit value is converted into a humidity threshold using

the same conversion equation shown in Section 6.2.3.

Reset Threshold

for Relative

Humidity Low Alert

0x14, 0x13

<13:0>

Registers 0x14, 0x13 sets the threshold for when the “RH Low”

alert condition is reset. After the alert is triggered, it will only

be reset after the measured RH goes above the value in this

The humidity used for the threshold is composed of 14-bits as

follows:

This 14-bit value is converted into a humidity threshold using

the same conversion equation shown in Section 6.2.3.

6.7 Reading the Sensor ID Number

The sensor ID is a 32-bit number that can be used to identify a given device. Each sensor has a unique ID that can

be used for traceability. The sequence to read the sensor ID is as follows:

1. Wake up the MVH4000D series sensor from sleep mode by sending its I2C address with a write bit, and

initiate a Read Sensor ID command by sending the command 0xD7.

2. Change the direction of communication by sending the MVH4000D I2C address and a read bit. The SCL line

is held low by the sensor while it retrieves the ID from internal memory to prevent data corruption. The

sensor takes approximately 10 µs to retrieve the ID from internal memory.

3. Once the request is completed by the MVH4000D series sensor, the SCL line is released and the chip waits

for the SCL clock signal to send the results. The sensor will then transmit the 4-byte sensor ID on the bus

for the master to capture, MSB first.

The command sequence to read the sensor ID is illustrated in Fig. 17.

0000010110000000

0's

Trigger Threshold [13:8]

Trigger Threshold [7:0]

0000010110000000

0's

Reset Threshold [13:8]

Reset Threshold [7:0]

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MVH4000D Series Datasheet

Rev. 0.98

Fig. 17: Read Sensor ID command sequence.

S1 0 1 0 1 0 0 0 ACK 1 1 0 1 0 1 1 1 ACK

S1 0 1 0 1 0 0 1 ACK

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 ACK

0 0 0 0 0 1 0 1 ACK 1 0 0 0 0 0 0 0 NACK P

S P

The MVH4000D chip reads the sensor ID

from internal memory, and the SCL line is

held low. This process takes ~10µs.

Bits generated by the master

Bits generated by the MVH4000D chip

I2C Address (7 bits) + read bit

Step 3 :

Sensor ID [31:24]

Sensor ID [23:16]

Sensor ID [15:8]

Sensor ID [7:0]

Start Sequence

Stop Sequence

Step 1 :

I2C Address (7 bits) + write bit

Read Sensor ID Command (0xD7)

Step 2 :

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MVH4000D Series Datasheet

Rev. 0.98

6.8 I2C Timing Specifications

The timing diagram for all I2C communications is shown in Fig. 18, and the minimum and maximum values for each

critical timing parameter (e.g., setup times, hold times) are listed in Table 11.

Fig. 18: I2C timing diagram.

Table 11: I2C Timing Parameters.

Parameter

Symbol

Min

Max

Units

SCL frequency

fSCL

400

kHz

Start bit setup time

tsu-start

0.1

µs

Start bit hold time

th-start

0.1

µs

Minimum SCL low width

tlow

µs

Minimum SCL high width

thigh

0.6

µs

Data setup time

tsu-data

0.1

µs

Data hold time

th-data

0.5

µs

Stop bit setup time

tsu-stop

0.1

µs

SDA unused time between stop and start bits

tidle

2.5

µs

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7 Package and PCB Information

The MVH4000D series sensors are packaged in a 2.5 ´ 2.5 ´ 0.9 mm 8-pin dual-flat no-leads (DFN)-style LGA

package.

7.1 Package Drawing

The mechanical drawing of the LGA package is shown in Fig. 19, and a suitable land pattern for soldering the sensor to a PCB is

shown in Fig. 20.

Fig. 19: LGA package drawing.

Fig. 20: LGA package land pattern (top view).

SCL

VDD

VSS

ALERT

SDA

Pin 1 Corner

2.50

2.30

0.3mm diameter

Circular Port

0.175

0.90 ± 0.10

TOP VIEW

SIDE VIEW

BOTTOM VIEW

Dimensions are in mm

Tolerances (unless otherwise specified)

Decimal

X.X ± 0.1

X.XX ± 0.05

X.XXX ± 0.030

0.6

0.10

0.50

1.60

0.25 x 0.35

Pin 1

Indicator

1.6

0.5

BSC

TOP VIEW OF PCB

Package

Outline

0.45

0.3

0.25

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MVH4000D Series Datasheet

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7.2 Tape and Reel Information

The MVH4000D series sensors are shipped in tape and reel packaging and enclosed in sealed anti-static bags.

Standard packaging sizes are 400, 1500, and 3000 units (please contact MEMS Vision for other volumes). The tape

has a 520mm leader (130 pockets) and a 410mm trailer (103 pockets). A drawing of the packaging tape is shown in

Fig. 21, which also shows the sensor orientation.

Fig. 21: Packaging tape drawing.

7.3 Soldering Information

Standard reflow ovens can be used to solder the MVH4000D series sensor to the PCB. The peak temperature (Tp)

for use with the JEDEC J-STD-020D standard soldering profile is 260°C. For manual soldering, the contact time must

be limited to 5 seconds at up to 350°C. In either case, if solder paste is used, it is recommended to use ‘no-clean’

solder paste to avoid the need to wash the PCB.

Note that reflow soldering is recommended for optimal performance. The recommended lead-free (RoHS

compliant) reflow soldering profile is shown in Fig. 22.

Fig. 22: Recommended lead-free soldering profile

After soldering, the humidity sensor element should be exposed to a humidity of 75% RH for at least 12 hours in

order to rehydrate the element. Otherwise, there may be an initial offset in the relative humidity readings, which

will slowly disappear as the sensor gets exposed to ambient conditions.

4.00

2.00

4.00

Ø1.5

Ø1.0 min

2.80

1.05

8.0

3.50

1.75

0.30

R0.30

MVH

33AA

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MVH4000D Series Datasheet

Rev. 0.98

7.4 PCB Layout Considerations

When designing the PCB, undesired heat transfer paths to the MVH4000D series chip must be minimized.

Excessive heat from other components on the PCB will result in inaccurate temperature and relative humidity

measurements. As such, solid metal planes for power supplies should be avoided in the vicinity of the

sensor since these will act as thermal conductors. To further reduce the heat transfer from other components on

the board, openings can be milled into the PCB as shown in Fig. 23.

Fig. 23: Thermal isolation of sensor using milled PCB openings.

8 Storage and Handling Information

Once the sensors are removed from their original packaging, it is recommended to store them in metal-in

antistatic bags. Polyethylene antistatic bags (light blue or pink in color) should be avoided as they may affect

sensor accuracy.

The nominal storage conditions for the MVH4000D series chip are at temperatures in the range of 10 to 50°C and

at humidity levels within the range of 20% to 60% RH. If the chip is stored outside of these ranges for extended

periods of time, the relative humidity sensor readings may exhibit an offset. The sensor can be brought back to its

calibration state by applying the following reconditioning procedure:

1. Baking at a temperature of 100°C with a humidity < 10% for 10 -12 hours.

2. Rehydrating the sensor at a humidity of 75% RH and a temperature between 20 to 30°C for 12 to 14 hours.

Note that the sensor may also return to its calibrated state if left at ambient conditions for a longer period of time.

MVH4000D

Milled Opening

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MVH4000D Series Datasheet

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conditions or characteristics. MEMS Vision assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting

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