有关高频VGA有数字控制

High-Frequency VGA Has Digital Control
TM
High-Frequency VGA Has Digital Control

Application Note April 1998 AN9641.1



Introduction R2, R3, and the -5V supply form a bias circuit that sets VB3
to -4.4V when there is no DAC output current (the voltage
You can use variable-gain ampliers (VGAs) in many types
across R1 is zero), which occurs at a digital input of all ones.
of system