Datasheet

Data Sheet AD8475
Rev. C | 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.
09432-168
Figure 54. FFT Results of the AD8475 Driving the AD7982
AD7982
AD8475
20V
–10V
0V
+10V
+7V TO +18V
+0.5V
+2.5V
+4.5
V
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
+V
S
+5V
–V
S
ADR435
20Ω
20Ω
270pF
270pF
1.3nF
VIO
CNV
GNDREF
VDD
SDO
SCK
SDI
+5V
+2.5V +1.8V TO +5V
10kΩ
10kΩ
0.1µF
+5V
09432-167
Figure 55. Attenuation and Level Shifting of Industrial Voltages to Drive Single-Supply Precision ADC