ad8475 Analog Devices, Inc., ad8475 Datasheet - Page 21

• Manufacturer Part Number: ad8475
• Description: Precision, Selectable Gain, Fully Differential Funnel Amplifier Ad8475
• Manufacturer: Analog Devices, Inc.

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.
+7V TO +18V
+10V
–10V
ADR435
0V
20V
+5V
NC
NC
Figure 55. Attenuation and Level Shifting of Industrial Voltages to Drive Single-Supply Precision ADC
+IN 0.4x
+IN 0.8x
–IN 0.8x
–IN 0.4x
+5V
+V
–V
S
S
AD8475
VOCM
–OUT
+OUT
4V
20Ω
20Ω
Rev. A | Page 21 of 24
270pF
270pF
4V
1.3nF
+4.5V
+0.5V
+4.5V
+0.5V
+2.5V
2.5V
0.1µF
Figure 54. FFT Results of the AD8475 Driving the AD7982
10kΩ
IN–
IN+
10kΩ
+2.5V
VDD
REF
+5V
AD7982
GND
SDO
SCK
CNV
VIO
SDI
+1.8V TO +5V
AD8475