AS8500 - Data Sheet

austriamicrosystems

Revision 1.2, 08-Junel-06

www.austriamicrosystems.com

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7.5.5

ZZR Zener-Zap register (188 bits ):

For the AS8500 the zener zap registers are set to a predefined default value. As an exception the TRIMA bits

in the ZTR subregister is factory adjusted for minimum amplifier offset to ensure optimum linearity over input

range.

Nr.

ZZR bits

183-187

163-182

53-162

0-52

NOTE

0

ZLO

ZTR

ZCL

2)

Notes:

1)

5 bits are reserved for:

- 1 bit eventually destroyed during testing,

- 2 bits for testing programmed 0 and 1

- 2 bits reserved for locking

2)

due to a limited driving capability of the ZZR-cells the maximum reading speed is limited to 500 kHz

subregister ZLO: Zener spare bits ( 5 bits )

Nr.

Name

SYMBOL

WORD WIDTH

Default Hex

1

Reserved bits

ZLO

5

F

subregister ZTR: trimming bits (20 bits)

Nr.

PARAMETER

SYMBOL

WORD

WIDTH

UNIT

0

TC of reference

TRIMBTC

5

Bits

1

absolute value of reference

TRIMBV

5

Bits

2

amplifier offset

TRIMA

5

Bits

3

current source for external

temperature

TRIMC

5

Bits

4

∑ trim bits

TRIMREG

20

Bits

subregister ZCL: calibration bits ( 110 bits )

Nr.

PARAMETER

SYMBOL

WORD

WIDTH

UNIT

0

Calibration G=6, I

CGI1

11

Bits

1

Calibration G=24, I

CGI2

11

Bits

2

Calibration G=50, I

CGI3

11

Bits

3

Calibration G=100, I

CGI4

11

Bits

4

Calibration U0

CAU0

11

Bits

5

Calibration U1

CAU1

11

Bits

6

Calibration U2

CAU2

11

Bits

7

Calibration U3

CAU3

11

Bits

8

Calibration U4

CAU4

11

Bits

9

Calibration U5

CAU5

11

Bits

10

∑ cal. Bits

ZCL

110

Bits

Calibration constants are selected dependent on state of M1 ( see table below). For M1=1 one of

CGI1 to CGI4 is selected according to selected gain of amplifier. For M1=0 the selection of the

calibration constants is defined by bits (cu2,cu1,cu0), which are part of CRA and CRB registers and

are defined via SDI interface independently of any other selection.