Ic-HO GENERAL PURPOSE SENSOR INTERFACE

iC-HO GENERAL PURPOSE SENSOR INTERFACE

iC-HO suits for various applications: mass flow metering, gas Applications sensing and pressure sensing. Besides the IC only a few external components are required: a cost effective microcontroller • Flow Sensors and/or an EEPROM, and the sensor itself. iC-HO is completely • Pressure Sensors controllable and monitorable by the microcontroller via SPI. • Gas Sensors Alternatively, stand-alone applications can boot from the CRC- secured external SPI EEPROM. Features • Ultra-low offset and low-noise PGA inputs Instrumentation PGA inputs allow gain and offset calibration, • 16-bit analog to digital conversion and temperature stabilization. An integrated look-up table (LUT) • Signal offset correction featuring 10 breakpoints can be used to correct nonlinear sen- • Configurable temperature drift compensation sor characterstics directly within the sensor interface IC. • Linearization of sensor characteristic by look-up table • Measurement data output digital and analog A digital PI-controller is available to drive a wide range of • Differential output of ratiometric voltage (10-bit D/A) MEMS heater resistors with up to 236 mW in an absolute or • Adjustable PI heater control relative temperature range from +25 °C to +660 °C. A fixed set • Signal and system monitoring functions point or sequence controller mode can be selected. • Fault indication at open-drain error output • Sensor resistor bias by adjustable current sources Matching constant current sources are available to bias up to • Integrated 8-bit temperature sensing three sensor resistors. The analog ratiometric differential output • SPI master (for EEPROM) and SPI slave interfaces for signal is implemented with a 10-bit D/A converter. device configuration and controller operation • 5 V supply voltage • Operating temperature range of -25 °C to +100 °C

VDDA VREF VAMP VDD

VDDAS Configurable Sensor Error Monitor SUS3 Bandgap Supply NERR SUS2 Reference SUS1 Osillator GNDAS

PGA Input Look Up Table Analog Output SPIN + A SNIN OUTP - D + OUTN - D A iC-HO

NCS_S Heater Control I/O Interface RBP SCK_S A RAM RBN SPI Slave MOSI_S D PI Main Control MISO_S HEATP Chip Temp. HEATN A Power-Down NCS_M D EEPROM Reset SCK_M IHEAT D Interface MOSI_M A SPI Master GNDHS MISO_M

GNDA GND

Am Kuemmerling 18 • D-55294 Bodenheim, Germany Tel. +49 61 35 / 92 92-300 • Fax +49 61 35 / 92 92-19 2 • http://www.ichaus.com iC-HO GENERAL PURPOSE SENSOR INTERFACE

Applications

GAS VDDA FLOW VDDAS VDDAS Configurable Sensor SENSOR Configurable Sensor PRESSURE SENSOR VDDAS SUS3 Supply SUS3 Supply SENSOR Configurable Sensor SUS3 SUS2 SUS2 Supply SUS2 SUS1 SUS1 SUS1 GNDAS GNDAS GNDAS

Rs PGA Input PGA Input PGA Input SPIN SPIN SPIN + A + A + A SNIN SNIN SNIN - - - Rup Rdown D D D iC-HO iC-HO iC-HO Heater Control Heater Control Heater Control Rb RBP Rb RBP RBP A A A RBN RBN Rb RBN D PI D PI D PI HEATP HEATP HEATP HEATN A HEATN A HEATN A D D D Rh IHEAT D IHEAT D IHEAT D A GNDHS A Rh A GNDHS GNDHS

Pin Functions Key Specifications

No. Name Function General 1 VDDAS Switched Sensor Supply Output Supply Voltage +5 V +/- 10 % 2 IHEAT Heater DAC Output Current Operating Temperature Range -25 °C to +100 °C 3 SPIN Positive Sensor Input 4 SNIN Negative Sensor Input Heater Driver 5 GNDAS Switched Sensor Ground Heater Driver Current up to 71.66 mA 6 GNDHS Switched Heater Ground Heater Voltage up to 3300 mV max. 7 HEATN Heater R ADC Negative Port PI Control Sampling Frequency 10 kHz 8 HEATP Heater R ADC Positive Port Resistor Temp. Coefficient 1953 … 3902 ppm/°K 9 RBN Bulk R ADC Negative Port Differential Analog Output 10 n.c. not connected Differential Output Voltage +/- 80 % of VDDA 11 RBP Bulk R ADC Positive Port DAC Resolution 10 bit 12 n.c. not connected 13 VDD +5 V Digital Supply Voltage Linearization Look-Up Table 14 GND Digital Ground Number of Breakpoints 10 15 NCS_M SPI Master (EEPROM), chip select Breakpoint Resolution 8 bit (address) 16 SCK_M SPI Master (EEPROM), clock line Correction Value 16 bit 17 MOSI_M SPI Master (EEPROM), data output 18 MISO_M SPI Master (EEPROM), data input SPI Interfaces 19 NCS_S SPI Slave, chip select SPI Slave to master MCU (host) 20 SCK_S SPI Slave, clock line SPI Master to slave EEPROM 21 MOSI_S SPI Slave, data input 22 MISO_S SPI Slave, data output 23 NERR Error Message Output (low active) Pin Configuration QFN32 5x5 mm² 24 OUTP Positive Analog Output 32 31 30 29 28 27 26 25 25 OUTN Negative Analog Output 26 GNDA Analog Ground 1 24 27 VDDA +5 V Analog Supply Voltage 2 23 28 VAMP ADC Voltage Range Reference I/O 3 22 4 21 29 VREF ADC Center Voltage Reference I/O 5 20 30 SUS3 Sensor Bias Output 3 6 19 31 SUS2 Sensor Bias Output 2 7 18 8 17 32 SUS1 Sensor Bias Output 1 TP Thermal Pad 9 10 11 12 13 14 15 16

This preliminary information is not a guarantee of device characteristics or performance. All rights to technical changes reserved.

Am Kuemmerling 18 • D-55294 Bodenheim, Germany Tel. +49 61 35 / 92 92-300 • Fax +49 61 35 / 92 92-19 2 • http://www.ichaus.com Rev. 2.0