Fast start-up circuit for low power current mirror

摘要

A fast startup circuit delivers current to a number of loads, comprising a P-channel current mirror circuit that provides current to an N-channel current mirror circuit that distributes current to a plurality of circuit networks. A first capacitor and a second capacitor are charged to two different voltages when the circuit is disabled and the two voltages are equalized when the circuit is enabled creating an initial operational starting point that has a steady state operating voltage that is the same as that during continuous operations. Thus there is no waiting for the fast startup circuit to start from an off condition and build up exponentially to a steady state operational level.

主权项

1. A fast startup circuit, comprising:
a) a first capacitor charged to zero volts when a disable switch is closed b) a second capacitor charged to a bias voltage when the disable switch is closed; and c) a current mirror circuit enabled in which the disable switch is opened and a enable switch is closed, wherein the current mirror circuit comprises the first and second capacitors, and wherein charge on the first and second capacitors equalize causing current in the current mirror circuit to start at a steady state operating value.