ZSC31150

Fast Automotive Sensor Signal Conditioner

Data Sheet

August 31, 2010

© 2010 Zentrum Mikroelektronik Dresden AG — Rev. 1.07

All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without

the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without

notice.

10 of 24

2

Circuit Description

2.1.

Signal Flow

The ZSC31150’s signal path is partly analog and partly digital. The analog part is realized differentially – this

means, the differential bridge sensor signal is internally handled via two signal lines, which are rejected

symmetrically around an internal common mode potential (analog ground = VDDA/2).

Consequently, it is possible to amplify positive and negative input signals, which are located within the

common mode range of the signal input.

Figure 2.1

Block Diagram of the ZSC31150

The differential signal from the bridge sensor is pre-amplified by the Programmable Gain Amplifier (PGA). The

Multiplexer (MUX) transmits the signals from either the bridge sensor, the external diode, or the separate

temperature sensor, to the Analog-to-Digital Converter (ADC) in a certain sequence (instead of the

temperature diode, the internal pn-junction (TS) can be used optionally). Afterwards, the ADC converts these

signals into digital values.

The digital signal correction takes place in the calibration microcontroller (CMC). It is based on a correction

formula located in the ROM and on sensor-specific coefficients stored in the EEPROM during calibration.

Dependent on the programmed output configuration, the corrected sensor signal is output as an analog value

or in a digital format (I²C

TM or ZACwireTM). The configuration data and the correction parameters can be

programmed into the EEPROM via the digital interfaces.

PGA

Programmable Gain Amplifier

MUX

Multiplexer

ADC

Analog-to-Digital Converter

CMC

Calibration Microcontroller

DAC

Digital-to-Analog Converter

BAMP

Buffer Amplifier – output buffer OPAMP

EEPROM

Non Volatile Memory for Calibration Parameters and Configuration

TS

On-chip Temperature Sensor (pn-junction)

ROM

Memory for Correction Formula and –Algorithm

RAM

Volatile Memory for Calibration Parameters and Configuration

PGA

TS

ADC

CMC

ROM

RAM

EEPROM

DAC

BAMP

ZACwireTM

I2C

MUX

Analog Block

Digital Block

ZSC31150

Digital

Data I/O

Analog

Out