Re: 1MHz output impedance query?
If you've got the power supply volts, an emitter follower would be good.
If your voltage is limited, then there are video speed opamps which will run off a single 5v supply and drive 50 Ohm lines. 741s need not apply! Have a look in Linear Technology, Analog Devices databooks and websites. TI and Natsemi also do some.
If you do this, I'd also shift to an LC filter and reduce the need for gain.
There's a lot of this sort of circuitry sprinkled around in Horowitz & Hill.
David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
|