Any one tried this circuitry ( current mirror) for the differential input stage
If so what are the adv or dis adv
I've seen DOUBLE curr mirrors in high quality designs
Any thoughts :?:
I'm not sure I undestand the question. A common configuration is a differential amplifier with a current mirror bridging the two diff-amp collectors. The advantage is it doubles the current swing and hence doubles the transconductance (gain) of the stage.
Yes its in the collector circuits of the differential input amplifier
My question is what sort of adv or disadv has this circuit
As I'm understanding it , it greatly improves the voltage driving capacity of the input stage, as it's load is greatly reduced due to the fact that the Collectors ( of the differential input ) are separated from the load by the collectors of the current mirror on the collector circuit, also the currents through the input transistors are VERY closely matched, therefore low dist
:?:
The real advantages of the current mirror load on a power amp diffamp input are two: (1) it balances the currents of the two transistors in the diffamp, resulting in about a 10:1 decrease in distortion within that stage and (2) it increases the gain from a few hundred up to a couple of thousand.