Use of current mirror

[ShadowReaper]

Hello,
as you already know, the current mirror provides a circuit with a current which is equal to the referenced current (Iref).
My question is: why don't we just use the Iref itself to power the circuit and we use the mirrored current?

[w2aew]

Hello,
as you already know, the current mirror provides a circuit with a current which is equal to the referenced current (Iref).
My question is: why don't we just use the Iref itself to power the circuit and we use the mirrored current?

Often times, current mirrors are used to supply the same magnitude current to different circuits/loads.  One reference can be mirrored many times to create many current sources tied to the same reference. Also, current mirrors can scale the reference current, thus creating current sources that are larger or smaller in magnitude by easily controlled ratios.