Patent ID: 7352245

Claim:
An auto-range current mirror circuit comprising: a front stage current mirror having a first adjustable amplifying rate, a current input adapted to connect to an input current and a current output, and generating a bias current in the current output; a rear stage current mirror having a second adjustable amplifying rate, an input terminal connected to the current output of the front stage current mirror and at least one output terminal, connected to the front stage current mirror in series to have the bias current from the front stage current mirror, and amplifying the bias current by the second amplifying rate to generate an output current in the output terminal; and at least one current sensing circuit, each electronically connects to the front and rear stage current mirrors and the input current and has a preset threshold current, wherein each current sensing circuit outputs a controlling signal to the front and rear stage current mirrors to adjust a suitable amplifying rate according to the present input current.