ZSC31150

Fast Automotive Sensor Signal Conditioner

Data Sheet

August 16, 2011

© 2011 Zentrum Mikroelektronik Dresden AG — Rev. 1.08

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.

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2.2.

Application Modes

For each application, a configuration set has to be established (generally prior to calibration) by programming

the on-chip EEPROM regarding to the following modes:



Sensor Channel

-

Sensor Mode: Ratiometric bridge excitation in voltage or current supply mode.

-

Input Range: The gain adjustment of the AFE with respect to the maximum sensor signal span and

the zero point of the ADC have to be chosen.

-

Additional Offset Compensation (XZC): The extended analog offset compensation has to be enabled,

if required; e.g., if the sensor offset voltage is near to or larger than the sensor span.

-

Resolution/Response Time: The A/D converter has to be configured for resolution and converting

scheme or ADC order (first or second order). These settings influence the sampling rate and the

signal integration time, and thus, the noise immunity.



Temperature

-

Temperature Measurement: The source for the temperature correction has to be chosen.

2.3.

Analog Front End (AFE)

The Analog Front End (AFE) consists of the 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 allowed common mode range.

Table 2.1

Adjustable Gains, Resulting Sensor Signal Spans and Common Mode Ranges

Input common mode range

14

No.

Overall Gain

Max. Span

[mV/V]

13

Gain

Amp1

Gain

Amp2

Gain

Amp3

XZC = Off

XZC = On

1

420

1.8

30

7

2

29 to 65

45 to 55

2

280

2.7

30

4.66

2

29 to 65

45 to 55

3

210

3.6

15

7

2

29 to 65

45 to 55

4

140

5.4

15

4.66

2

29 to 65

45 to 55

5

105

7.1

7.5

7

2

29 to 65

45 to 55

6

70

10.7

7.5

4.66

2

29 to 65

45 to 55

7

52.5

14.3

3.75

7

2

29 to 65

45 to 55

8

35

21.4

3.75

4.66

2

29 to 65

45 to 55

9

26.3

28.5

3.75

3.5

2

29 to 65

45 to 55

10

14

53.75

1

7

2

29 to 65

45 to 55

11

9.3

80

1

4.66

2

29 to 65

45 to 55

12

7

107

1

3.5

2

29 to 65

45 to 55

13

2.8

267

1

1.4

2

32 to 57

not applicable

13

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

Span is calculated by the following formula: Span = 75% / gain

14

Bridge in voltage mode, containing maximum input signal (with XZC: +300% Offset), 14-bit accuracy. Refer to the 'ZSC31150

Functional Description' for usable input signal/common mode range at bridge in current mode.