AD9943 Analog Devices, AD9943 Datasheet - Page 16

• Manufacturer Part Number: AD9943
• Description: Complete 10-Bit and 12-Bit/ 25 MHz CCD Signal Processors
• Manufacturer: Analog Devices

AD9943/AD9944
A/D CONVERTER
The ADC uses a 2 V input range. Better noise performance
results from using a larger ADC full-scale range. The ADC uses
a pipelined architecture with a 2 V full-scale input for low noise
performance.
VARIABLE GAIN AMPLIFIER
The VGA stage provides a gain range of 6 dB to 40 dB,
programmable with 10-bit resolution through the serial digital
interface. The minimum gain of 6 dB is needed to match a 1 V
input signal with the ADC full-scale range of 2 V. A plot of the
VGA gain curve is shown in Figure 13.
VGA
Gain
( )
dB
=
(
VGA
Code
×
. 0
035
dB
)
+
5
3 .
dB
Rev. B | Page 16 of 20
36
30
34
18
12
42
6
0
127
255
Figure 13. VGA Gain Curve
VGA GAIN REGISTER MODE
383
511
639
767
895
1023