MEMS Mass Flow Sensor Description The PFLOW2001 series of mass flow sensors are made with micromachined (MEMS) sensing elements that offer an innovative thermal sensing principle with excellent linearity and removal of gas sensitivity of some common gases. This PFLOW2001 Series mass flow sensor series offer a fully customizable flow dynamic range of 100:1 with the full-scale flowrate from 30 sccm to 5000 sccm. The sensors are opted with digital and analog interface, bi-directional sensing capability with an operational temperature range of -25 to 85 °C (-13 to 185 °F). Wide supply voltage 8 …...

Revision History Rev. Change No. 1.0 Initial revision 1.1 Update of the I2C communication PFLOW2001 I2C Application Note Step model of the sensor

SPECIFICATIONS Absolute maximum ratings (1) Item Supply voltage, VDDmax I2C bus voltage, VDDIOmax Low voltage version Normal and low voltage version I2C frequency, fI2Cmax Maximum common mode pressure, Pmax Maximum overflow, Qmax of full scale flowrate Maximum flowrate change of full scale flowrate Operating temperature range, Top Storage temperature, Tstg Mechanical shock Notes: 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. 2. sccm denotes standard cubic centimeters per minute. Standard conditions: 20°C, 101.325kPa, dry and clean air Performance characteristics...

Electrical Characteristics (Test conditions: VDD = 8-15VDC, Ta = 20°C, RHa = 30…70%, unless otherwise stated) Item Supply current Minimum output load Analog output (rated), Vout (3) 1 Low voltage version Low voltage version Analog null voltage - bidirectional Analog null voltage unidirectional Digital and analog output analog & digital output I2C Normal and low voltage version Analog null drift Analog maximum output (5) Digital maximum output I2C bus voltage (6) Resolution digital output Digital null offset (8) Digital null drift Notes: 1. Warm-up time is the time from power on to the first stable...

Pressure drop characteristics Part no. Flow Range Pressure drop MECHANICAL DIMENSIONS Flow direction Flow direction from left to right for uni-directional sensors. Please refer t

ELECTRICAL INTERFACE Digital and analog version pinout Pin# Analog voltage output I2C clock Figure 2 Digital and analog version (VI2C) pin assignment Analog only version pinout The only analog 3-pin version is as a replacement for retrofit and older designs, where only analog output is required. Pin# Analog voltage output GND Figure 3 Analog only 3-pin version GAS CORRECTION FACTORS Gas type Air Oxygen (O2) Nitrogen (N2) Argon (Ar) Hydrogen (H2) Carbon dioxide (CO2) *For Hydrogen applications please contact the manufacturer. The custom factory calibration with H2 needs to be performed, to provide...

TYPICAL ANALOG OUTPUT

TYPICAL DIGITAL OUTPUT

Figure 7. Analog and I2C interface connection diagram When not using the analog output, the pin 1 shall be left unconnected (floating). Shortening Pin 1 to GND will cause malfunction of the sensor. When not using the digital I2C output, the pin 4 and pin 5 shall be left unconnected (floating). Shortening Pin 4 and/ or 5 to GND will cause malfunction of the sensor. Only for low power version of the sensor the VDD and VDDIO can be connected together.

DIGITAL I2C COMMUNICATION I2C interface command description The default I2C address of the sensor is 0x50. Command Name Read/ Write Width (Byte) Notes Write the new address in 8-bit format It will be transformed to 7-bit (shifted right) i.e.: 0x0A (8-bit) -> 0x05 (7-bit) Send new address in 2 Bytes + CRC i.e.: new I2C address is 0x05 (7-bit), then send 3 Bytes: 0x00, 0x0A, 0x36 Please refer to Application note for details and code sample Flowrate offset reset Serial number Flow rate Write to the sensor 2-bytes of any fixed value (will be ignored). Ensure no-flow conditions HEX, ASCII code 18-Bytes...

5. All the data from the sensor are transmitted in following sequence: 2-Bytes Data, 1 Byte CRC, 2Bytes data, 1-Byte CRC. i.e: Serial number: 2A 2A FA 42 31 E6 52 33 BF 31 33 75 34 33 34 2A 2A FA  without CRC: 2A 2A 42 31 52 33 31 33 34 33 2A 2A  in ASCII: **B1R31343** 6. All data written to the sensor shall be in 2-Byte format followed by 1 Byte CRC. i.e.: reset flow rate offset: Send to the sensor the command to reset offset: 0x00, 0xF0 Write to the sensor any 2-Byte fixed value i.e. 0xAA, 0x55 Follow it by CRC-8: 0x36 7. Refer to the PFLOW 2001 I2C Application Note for details [1] I2C interface...

CRC checksum calculation The 8-bit CRC checksum transmitted after each two data bytes (int 16) is generated by a CRC algorithm. Its properties are listed in the following table. To calculate the checksum, only these two previously transmitted data bytes are used. Property Protected data Reflect input Reflect output ORDERING INFORMATION The product part number is composed of the product model number and suffix indicating the full-scale flow rate, mechanical connection, output format as well as the applicable gas. Refer to the following for the product order: PFLOW2001 Gas (A: air, N2, O2, Ar;...

We are here for you. Addresses and Contacts. Headquarter Switzerland: Office Germany: Angst+Pfister Sensors and Power AG Angst+Pfister Sensors and Power Deutschland GmbH Scan here and get an overview of personal contacts! for sensors and power solutions