MOSFET capacitor

Dec 30, 2005 4 Replies

Hello, I am designing an IC amplifier and i want to remove the DC component from the output. I thought of using a capacitor. How can i implement a capacitor using a MOSFET. I heard i can connect the drain to source but how do i control the equivalent capacitance?



MOSFET capacitance is simply the gate capacitance.

HOWEVER: There is a series resistance component which varies with bias, and it is NOT modeled by the MOSFET Spice model alone.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | "Winners never quit, quitters never win", Jack Bradley Budnik ~1956

Maybe you could elaborate on the exact meaning of " I am designing an IC amplifier " first before going any further ?

Graham

I think you need to spend some more time learning the process. You may have a capcitor option wich gives less voltage dependence by using a high implant, or possibly poly-poly capacitor.

Be careful when us> Hello,

If you need to ask this, it would be best to forget it.

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