ADS5287

SBAS428D – JANUARY 2008 – REVISED JUNE 2012

www.ti.com

PROGRAMMABLE GAIN

ADDRESS

IN HEX

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

NAME

X

X

X

X

GAIN_CH1<3:0>

X

X

X

X

GAIN_CH2<3:0>

2A

X

X

X

X

GAIN_CH3<3:0>

X

X

X

X

GAIN_CH4<3:0>

X

X

X

X

GAIN_CH5<3:0>

X

X

X

X

GAIN_CH6<3:0>

2B

X

X

X

X

GAIN_CH7<3:0>

X

X

X

X

GAIN_CH8<3:0>

In applications where the full-scale swing of the analog input signal is much less than the 2VPP range supported

by the ADS5287, a programmable gain can be set to achieve the full-scale output code even with a lower analog

input swing. The programmable gain not only fills the output code range of the ADC, but also enhances the SNR

of the device by utilizing quantization information from some extra internal bits. The programmable gain for each

channel can be individually set using a set of four bits, indicated as GAIN_CHN<3:0> for Channel N. The gain

setting is coded in binary from 0dB to 12dB, as shown in Table 6.

Table 6. Gain Setting for Channel 1

GAIN_CH1<3>

GAIN_CH1<2>

GAIN_CH1<1>

GAIN_CH1<0>

CHANNEL 1 GAIN SETTING

0

0

0

0

0dB

0

0

0

1

1dB

0

0

1

0

2dB

0

0

1

1

3dB

0

1

0

0

4dB

0

1

0

1

5dB

0

1

1

0

6dB

0

1

1

1

7dB

1

0

0

0

8dB

1

0

0

1

9dB

1

0

1

0

10dB

1

0

1

1

11dB

1

1

0

0

12dB

1

1

0

1

Do not use

1

1

1

0

Do not use

1

1

1

1

Do not use

20

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