H12P1: Current Source

We often need a precision current source in a circuit. An operational amplifier gives us one way to make a precisely controlled current flow through a load whose properties are not precisely known. The following handy circuit is often the answer.

i=10, v=5, A=infinity vs=+-5.

Question

H12P1: Current Source

We often need a precision current source in a circuit. An operational amplifier gives us one way to make a precisely controlled current flow through a load whose properties are not precisely known. The following handy circuit is often the answer.

i=10, v=5, A=infinity vs=+-5.

anonymous · Answer

Mainly, current sources are used to provide BIASING in circuit. In-fact, OPAMP itself requires a biasing circuit and in analog IC's the current biasing technique is used. So OPAMP itself requires a current source. 

The most popular circuit for current source is CURRENT MIRROR. It can be designed either by BJT or MOSFET. In designing of current source, there the output impedance of circuit must be infinity ( ideally). so that any change in voltage can't change current through it.

anonymous · Answer

a) 500
b) 1000