AD8475

Rev. B | Page 21 of 24

The differential RC network between the AD8475 output and the

ADC provides a single-pole filter that reduces undesirable

aliasing effects and high frequency noise. The common-mode

bandwidth of the filter is 29.5 MHz (20 Ω, 270 pF), and the

differential bandwidth is 3.1 MHz (40 Ω, 1.3 nF).

The VOCM input is bypassed for noise reduction, and set

externally with 1% resistors to maximize output dynamic

range on a single 5 V supply.

Figure 54. FFT Results of the AD8475 Driving the AD7982

AD7982

AD8475

20V

–10V

0V

+10V

+7V TO +18V

+0.5V

+2.5V

+4.5V

NC

NC

+IN 0.4x

–IN 0.4x

+IN 0.8x

–IN 0.8x

4V

+0.5V

2.5V

+4.5V

4V

–OUT

IN–

IN+

+OUT

VOCM

+5V

ADR435

20Ω

20Ω

270pF

270pF

1.3nF

VIO

CNV

GND

REF

VDD

SDO

SCK

SDI

+5V

+2.5V

+1.8V TO +5V

10kΩ

10kΩ

0.1µF

+5V

Figure 55. Attenuation and Level Shifting of Industrial Voltages to Drive Single-Supply Precision ADC