资 源 简 介
The AD9280ARS features an opTIonal clamp circuit for dcrestoraTIon of video or ac coupled signals. Figure 24 shows theinternal clamp circuitry and the external control signals neededfor clamp operaTIon. To enable the clamp, apply a logic high tothe CLAMP pin. This will close the switch SW1. The clampamplifier will then servo the voltage at the AIN pin to be equalto the clamp voltage applied at the CLAMPIN pin. After thedesired clamp level is attained, SW1 is opened by takingCLAMP back to a logic low. Ignoring the droop caused by theinput bias current, the input capacitor CIN will hold the dcvoltage at AIN constant unTIl the next clamp interval. The inputresistor RIN has a minimum recommended value of 10 W, tomaintain the closed-loop stability of the clamp amplifier.
