Thanks sunking and Btrend!
2) ===> UGB > 1.664G
===> if A0= 1000 (i.e. 60dB), then ω0 > 1.664M rad/s ===> f0 > 264 kHz/s
/***According to what you said, does the amp( A0=10000 (80dB), f0 > 26.4 kHz/s) can meet the request?
3). for S/H circuit, β can be reduced to 1, so the spec. of OP can be loosen.
/***Sorry, I don't very understand what's mean. Can you explain it more clearly?
which circuit structure should be choosed ? it depends on ur application.
/***In fact, when I use a novinverting sampling structure and an amp (A0=10000 (80dB), f0 = 28 kHz/s), the amplifier can only work well at most at 2MHz sampling freq. I don't know whether it is due to the limitation of sampling cor amps circuit. if due to the forth, is there any high-speed sampling tech. to realize 10MHz sampling freq.? [/i]