ZSSC3136 Datasheet

© 2016 Integrated Device Technology, Inc.

11

January 22, 2016

The digital signal conditioning is processed by the calibration microcontroller (CMC). It is based on a correction

formula that uses sensor-specific coefficients determined during calibration. The formula is located in ROM, and

the sensor-specific coefficients are stored in EEPROM. Depending on the programmed output configuration, the

conditioned sensor signal is output as an analog signal, or alternatively can be readout via a digital serial interface

(I²C™ or ZACwire™). The configuration data and the correction parameters must also be programmed into the

EEPROM via the digital interfaces.

2.2.

Application Modes

For each application, a configuration set must be established by programming the on-chip EEPROM for the

following modes:

signal span and the zero point of the A/D conversion must be selected.

the sampling rate and the signal integration time, and thus, the noise immunity.

2.3.

Analog Front-End (AFE)

The analog front-end (AFE) consists of the three-stage programmable gain amplifier (PGA), the multiplexer

(MUX), and the analog-to-digital converter (ADC).

2.3.1.

Programmable Gain Amplifier (PGA)

Table 2.1 shows the adjustable gains, the sensor signal spans, and the valid common mode range.

Table 2.1

Adjustable Gains, Resulting Sensor Signal Spans and Common Mode Ranges

PGA Gain

Maximum Span

1)

Input Common Mode Range

105

7.1

29 to 65

70

10.7

29 to 65

52.5

14.3

29 to 65

35

21.4

29 to 65

26.3

28.5

29 to 65

14

53.75

29 to 65

9.3

80

29 to 65

7

107

29 to 65

2.8

267

32 to 57

1)

Recommended maximum internal signal range is 75% of supply voltage.

Span is calculated by the following formula: Span = 0.75 (VBR_T – VBR_B) / Gain.