PMOS Current mirror load single output preamplifier

[Tanvi Singh]

How to keep the PMOS operating in saturation region in PMOS Current mirror load single output preamplifier with both the sides identical we are finding the two PMOS working in cut off region . And hence the current is not identical in both the arms. we have decreased the W/L ration of upper PMOS to increase the drop and hence making vgs greater than threshold voltage . And also the current of the circuit we have tried increasing by increasing the tail current source current value but still the required output and proper functioning of current mirror is not obtained. Kindly suggest the possible solutions and the problem to get proper results. Thank you

 

[AMS012]

If you keep increasing the tail current, the diode connected PMOS should enter saturation region for a given size. Make sure that when the drop across PMOS increases, the NMOS devices below are working as per your expectation.

 

[Tanvi Singh]

Thanks for your help!
We got our mosfets in proper operating regions.However we are not able to get the proper gain.We tried increasing the tail current and decreasing the (W/L) ratio to increase the output gain. The circuit is in fact de-amplifying.

The pmos and nmos are working in saturation region and the current is mirrored properly.

Thanks !

 

[arunkumarshanti]

Hi Tanvi,

Please upload the circuit.