ZSSC3154 Datasheet

© 2016 Integrated Device Technology, Inc.

14

January 22, 2016

2.4.2

Measurement Cycle

The measurement cycle is controlled by the CMC. Depending on EEPROM settings, the multiplexer (MUX)

selects the following input signals in a defined sequence:

• Differential bridge sensor signal

• Conditioning temperature for bridge sensor signal conditioning calculation

• Temperature sensor signal

• Single-ended half-bridge sensor signal measured against an internal reference voltage

• Internal offset of the analog front end (auto-zero compensation)

• Diagnostic signals

The cycle diagram in Figure 2.2 shows the basic structure of the measurement cycle. After power-on, the startup

routine is processed, which performs all required measurements to expedite acquiring an initial valid conditioned

sensor output. After the startup routine, the normal measurement cycle runs.

Figure 2.2

Example of Measurement Cycle with Bridge Sensor Signal and Temperature Measurement

(For detailed descriptions of various possible cycle configurations, refer to the ZSSC3154 Functional Description.)

CTAZ

CT

BRAZ

BR

BIST

BISTAZ

BR

BR

BRAZ

BR

CTAZ

BR

CT

BR

SSCP

BR

SSCN

18

Measurements

per Cycle

Startup

Measurement Cycle

BR

BR

T

TAZ

Measurement Cycle with Bridge Signal and Temperature Output

BIST

BR

Bridge Sensor

Measurement

Auto-Zero Measurement

CT

Calibration Temperature

Measurement

Auto-Zero Measurement

T

Temperature

Measurement

TAZ

Temperature

Auto-Zero Measurement

Bridge Sensor Signal

Main Signals Measurement

Measurement Cycle Phases

Analog Output Updated

AFE Built-In Self-Test

Measurement

Auto-Zero Measurement

Positive-Biased Measurement

Negative-Biased Measurement

Safety Functions Measurement

Temperature Signal

2.4.3

Conditioning Calculation

The digitalized value for the bridge signal and, if selected, for the temperature or the half-bridge signal are

processed with the conditioning formulas to remove offset and temperature dependency and to compensate

nonlinearity. The result is a non-negative 15-bit value in the range [0; 1).