AD977/AD977A

–15–

REV. D

Table III. Output Codes and Ideal Input Voltages

Digital Output

Two’s Complement Straight Binary

Description

Analog Input

(SB/

BTC LOW)

(SB/

BTC HIGH)

Full-Scale Range

±10 V

±5 V

±3.33 V

0 V to 10 V

0 V to 5 V

0 V to 4 V

Least Significant Bit

305

µV

153

µV

102

µV

153

µV

76

µV

61

µV

+Full Scale (FS–1 LSB)

9.999695 V

4.999847 V

3.333231 V

9.999847 V

4.999924 V

3.999939 V

0111 1111 1111 1111

1111 1111 1111 1111

Midscale

0 V

0 V

0 V

5 V

2.5 V

2 V

0000 0000 0000 0000

1000 0000 0000 0000

One LSB Below Midscale

–305

µV

–153

µV

–102

µV

4.999847 V

2.499924 V

1.999939 V

1111 1111 1111 1111

0111 1111 1111 1111

–Full Scale

–10 V

–5 V

–3.333333 V 0 V

0 V

0 V

1000 0000 0000 0000

0000 0000 0000 0000

Table IV. Input Ranges, Offset and Full-Scale Errors Without External Resistors

AD977

Offset Error

Full-Scale Error

AD977A

Offset Error

Full-Scale Error

Input Range

A/B/C Grade

A/B/C Grade

Input Range

A/B/C Grade

A/B/C Grade

–9.890 V to 9.90 V

±25 mV/±25 mV

±0.75%/±0.50%

–9.800 V to 9.970 V

±40 mV/±40 mV

±0.80%/±0.55%

–4.943 V to 4.995 V

±25 mV/±25 mV

±0.75%/±0.50%

–4.900 V to 4.985 V

±40 mV/±40 mV

±0.80%/±0.55%

–3.295 V to 3.330 V

±25 mV/±25 mV

±0.75%/±0.50%

–3.267 V to 3.323 V

±40 mV/±40 mV

±0.80%/±0.55%

0.008 V to 9.946 V

±10 mV/±10 mV

±0.75%/±0.50%

0.007 V to 9.893 V

±10 mV/±10 mV

±0.75%/±0.50%

0.004 V to 5.023 V

±10 mV/±10 mV

±0.75%/±0.50%

0.004 V to 5.039 V

±10 mV/±10 mV

±0.75%/±0.50%

0.003 V to 4.010 V

±10 mV/±10 mV

±0.75%/±0.50%

0.003 V to 4.016 V

±10 mV/±10 mV

±0.75%/±0.50%

200

100

33.2k

2.2 F

2.2 F

REF

AGND2

CAP

AGND1

AD977A

AD8031

200

33.2k

2.2 F

2.2 F

REF

AGND2

CAP

AGND1

AD977A

100

AD8031

200

100

33.2k

2.2 F

2.2 F

REF

AGND2

CAP

AGND1

AD977A

AD8031

a.

c.

b.