Automotive Sensor Signal Conditioner for Thermocouples ZSSC4175D-01 with SENT Output Datasheet Description Features The ZSSC4175D-01 is a member of IDTs family of CMOS Two differential thermocouple element inputs and an on-chip integrated circuits for highly accurate amplification and sensor- temperature sensor, available for cold-junction compensation specific correction of two signals from thermocouple elements. and temperature output Operating temperature range: -40C to 150C Digital compensation of offset, sensitivity, temperature drift, and nonlinearity is accomplished via a 16-bit RISC microcontroller. Accuracy: up to 5K at 1000C hot junction Calibration coefficients and configuration data are stored in the Supports N-type thermocouples ZSSC4175D-01 nonvolatile memory (NVM), which is reliable in NVM memory for configuration, calibration data, and automotive applications. configurable measurement and conditioning functionality Measured values are provided via a digital SENT interface. The SENT output compliant to SAE J2716 JAN2010 (SENT SENT interface enables transmission of conditioned thermocouple Rev. 3) and APR2016 (SENT Rev. 4) standard (refer to data via its Fast Channel as well as transmission of supplementary section 7.6 for details) data via its Serial Data Message (SDM) Channel (also referred to Supports output of one or more thermocouple signals and as the slow channel) using only one output pin. End-of-line product identification via a single SENT interface connection calibration is also supported through this output pin via a One-Wire End-of-line calibration process minimizes production costs Interface (OWI). The ZSSC4175D-01 and the calibration equipment communicate digitally, so the noise sensitivity is greatly No external trimming or components required reduced. Digital calibration helps keep assembly cost low as no Qualified according to AEC-Q100 Grade 0 trimming by external devices or lasers is needed. Enhanced diagnostic features for sensor module The ZSSC4175D-01 is optimized for automotive environments by over-voltage and reverse-polarity protection circuitry, excellent Physical Characteristics electromagnetic compatibility, and multiple diagnostic features. Supply voltage: 4.5V to 5.5V Over-voltage and reverse-polarity protection up to 18V Typical Applications Input span: -5mV to 80mV thermocouple voltage range Exhaust Systems ADC resolution: 14-bit Output resolution: 12-bit via SENT interface Available Support Package: 24-QFN (4 4 mm wettable flanks) Evaluation Kit Application Notes ZSSC4175D-01 Basic Circuit Calculation Tools R SENT BR1P DOUT SENT C LOAD BOT EMC Filter VSSE GND BR1N C1 VDDE VCC TS1 VSSA TOP SCL SCL TS2 SDA SDA BR2P VSSA VSSA C2 EMC Filter BR2N VDDA VDDA VSSA 2019 Integrated Device Technology, Inc. 1 June 7, 2019 ZSSC4175DZSSC4175D-01 Datasheet Contents 1. Pin Assignments ...........................................................................................................................................................................................5 2. Pin Descriptions ............................................................................................................................................................................................5 3. Absolute Maximum Ratings ..........................................................................................................................................................................6 4. Operating Conditions ....................................................................................................................................................................................7 5. Electrical Characteristics ..............................................................................................................................................................................8 5.1 Supply Current and System Operating Conditions ..............................................................................................................................8 5.2 Analog Front-End Characteristics ........................................................................................................................................................9 5.3 Internal Temperature Measurement ....................................................................................................................................................9 5.4 Thermocouple Measurement ...............................................................................................................................................................9 5.5 SENT Output .......................................................................................................................................................................................9 5.6 System Response .............................................................................................................................................................................10 6. Interface Characteristics and Nonvolatile Memory .....................................................................................................................................11 6.1 I2C Interface Only for production purposes ....................................................................................................................................11 6.2 ZACwire One-Wire Interface ..........................................................................................................................................................11 6.3 Nonvolatile Memory (NVM) ...............................................................................................................................................................11 7. Circuit Description ......................................................................................................................................................................................12 7.1 General Operation Description ..........................................................................................................................................................12 7.2 Signal Path ........................................................................................................................................................................................13 7.3 Signal Conditioning ............................................................................................................................................................................14 7.3.1 Thermocouple Sensor Signal Conditioning ........................................................................................................................14 7.3.2 Internal Temperature Sensor Signal Conditioning ..............................................................................................................14 7.4 Analog Front-End ..............................................................................................................................................................................14 7.4.1 Overview .............................................................................................................................................................................14 7.4.2 SCCM .................................................................................................................................................................................14 7.4.3 Input Multiplexer .................................................................................................................................................................14 7.4.4 Programmable Gain Amplifier ............................................................................................................................................14 7.4.5 Analog-to-Digital Converter ................................................................................................................................................14 7.5 Signal Measurement ..........................................................................................................................................................................14 7.5.1 Thermocouple Element Measurement ...............................................................................................................................14 7.5.2 Internal Temperature Measurement ...................................................................................................................................14 7.5.3 Isolation Conductance Measurement (Giso) ......................................................................................................................15 7.5.4 Thermocouple Resistor Measurement (Ropen) ..................................................................................................................15 7.5.5 Measurement Cycle ............................................................................................................................................................15 7.6 SENT Output .....................................................................................................................................................................................15 7.6.1 Overview .............................................................................................................................................................................15 7.6.2 SENT Fast Channel Modes and Frame Format .................................................................................................................16 7.6.3 SENT SDM Channel Modes ...............................................................................................................................................17 7.6.4 SENT Output Operation Modes ..........................................................................................................................................18 7.6.5 SENT Pulse Shaping ..........................................................................................................................................................19 2019 Integrated Device Technology, Inc. 2 June 7, 2019