Hi All I am a bit confused with the differential input amplifier concept, I hope experts out there can give me some assistant.
For the differential input amplifier to achieve the max dc gain, does the Vin- and Vin+'s dc voltage must be zero? I uses the netlist below for implementing my 2 stage amplifier, it seems that both Vin- and Vin+ equals to 0V gives me the highest dc gain (64dB)
If Vin- and Vin+ all equals to zero, does that mean there is no input- offset voltage?
Finally, I am just wondering, does the max and min output voltage of the 2 stage amplifier depend only on VDD and Vss values respectively? I simulated the .dc response and the plot shows that the max output voltage is 2.5V and the min is -2.5V which are VDD and Vss. So, do VDD and Vss control the output voltage or is it just a coincident?
I would be really appreciate if someone could clarify my questions above.
Thanks*Netlist: VDD 1 0 DC 2.5 Vss 7 0 DC -2.5 VbiasQ5 2 0 DC 1.5
- Mp5 8 2 1 1 p1 W=200u L=1.2u
- simple compensation network
- VINL 9 0 dc 0 VINH 11 0 dc 0 ac 1
- Microwind 0.6 micron foundry level 3 models