ZSC31150 Datasheet

© 2016 Integrated Device Technology, Inc.

17

December 6, 2016

2.8 Failsafe Features, Watchdog and Error Detection

The ZSC31150 detects various possible errors. A detected error is indicated by a change in the internal status in Diagnostic Mode (DM). In

this case, the analog output is set to LOW (minimum possible output value; i.e., the lower diagnostic range LDR) and the output registers of

the digital serial interface are set to a significant error code.

A watchdog oversees the continuous operation of the CMC and the running measurement loop. The operation of the internal clock oscillator

is verified continuously by the oscillator failure detection.

A check of the sensor bridge for broken wires is done continuously by two comparators watching the input voltage of each input (sensor

connection and short check). Additionally, the common mode voltages of the sensor and sensor input short are watched continuously (sensor

aging).

Different functions and blocks in the digital section, e.g. the RAM, ROM, EEPROM, and register content, are watched continuously. Refer to

the ZSC31150 Functional Description for a detailed description of safety features and methods of error indication.

2.9 High Voltage, Reverse Polarity, and Short Circuit Protection

The ZSC31150 is designed for 5V power supply operation.

The ZSC31150 and the connected sensor are protected from overvoltage and reverse polarity damage by an internal supply voltage limiter.

The analog output AOUT can be connected with all potentials (short circuit, over-voltage, and reverse voltage) in the protection range under

all potential conditions at the VDDE and VSSE pins.

All external components (see section 3) are required to guarantee this operation. The protection is not time limited. Refer the ZSC31150

Technical Note – High Voltage Protection for a detailed description of protection cases and conditions.