Patent ID: 7436248

Claim:
A current driving circuit supplied with power having a first potential and a second potential and receiving a reference voltage, the current driving circuit having a bias voltage generator and a plurality of constant current drivers, the bias voltage generator receiving the reference voltage, generating a bias voltage, and using the bias voltage to regulate a reference current, the constant current drivers receiving the bias voltage and outputting driving currents related to the reference current, wherein each constant current driver comprises: a first node; a first transistor of a first conductive type, having a first main electrode receiving the first potential, a second main electrode connected to the first node, and a control terminal receiving the bias voltage; a second transistor of a second conductive type, having a first main electrode receiving the second potential, a second main electrode connected to the first node, and a control terminal connected to the first node; and a third transistor of the second conductive type, having a first main electrode receiving the second potential, a second main electrode outputting one of the driving currents, and a control terminal connected to the first node, wherein the bias voltage generator comprises: a second node; a third node; an operational amplifier having a non-inverting input terminal receiving the reference voltage, an inverting input terminal connected to the second node, and an output terminal outputting the bias voltage; a fourth transistor of the first conductive type, having a first main electrode receiving the first potential, a second main electrode connected to the third node, and a control terminal connected to the output terminal of the operational amplifier; a fifth transistor of the second conduetive type, having a first main electrode receiving the second potential, a second main electrode connected to the third node, and a control terminal connected to the third node; a sixth transistor of the first conductive type, having a first main electrode receiving the second potential, a second main electrode connected to the second node, and a control terminal connected to the third node; and a resistor having one terminal connected to the second node and another terminal receiving the first potential.