Vds control of MOSFET

[pankajdudulwar]

how to control vds voltage of a mosfet

HI,
How one can control the Vds of the transistors in the CASCODE amplifier (i.e telescopic). In telescopic amplifier circuit their is lot of drop across the cascode PMOS which in turn drives other NMOS transistors in the Linear region. Please advice me how I can drive all the MOS properly with respective overdrive across it.
Waiting eagerly for the solution. Please refer the circuit mention in the Razavi book in the Ninth chapter

 

[smoked]

linear vds control

You can increase W/L ratio for less voltage drop (Vds) of each cascode device and also use a low voltage cascode current reference to get a minimum voltage of 2Vds(sat) for each cascode pair. You should check Page 273 of Gray&Meyer 4th ed. as an example reference circuit.