電流反饋式運(yùn)算放大器應(yīng)用電路指南

1、Current Feedback Op Amp Applications Circuit Guide IntroductionNo two high-speed application are the same or at least it seems that way. Nonetheless, while every system has its particular requirements, many of the design techniques are common among different designs. This application note illus-trat

2、es design techniques utilizing current-feedback op amps and the practical circuits where they are used. The circuits should work well with any Comlinear op amp if appropriate adjustments are made for different feedback resistance val-ues.Inverting Gain As with voltage-feedback op amps, the ratio of

3、the feedback resistor to the gain-setting resistor determines the voltage gain in current-feedback op amp circuits. With current feed-back, however, dynamic performance is largely independent of the voltage gain. (Seeapplication note AN300-1for a technical discussion of current-feedback. Also, the o

4、ptimum feedback resistor value for a current-feedback op amp is indicated in the datasheet.National Semiconductor OA-07David Potson May 1988 Current Feedback Op Amp Applications Circuit Guide OA-07Differential Line ReceiverThis circuit provides good common mode rejection and 50termination for signal

5、s which need to be transmitted through coaxial lines. 01278107Driving Capacitive LoadsThe damping resistor, R S , reduces pulse-response over-shoot and frequency-response peaking caused by the load capacitance. The value of R S may be found on some of the op amp datasheet or may be found experimentally.Simple Offset AdjustmentThe Zener diode biasing resistor, R, should be chosen to provide a diode current of 7.5mA. 3Non-Inverting Composite AmplifierAs with the previous circuit, R B is chosen for minimum output voltage at the OP-27when V OUT is