Patent ID: 11862058
Assignee: LAPIS TECHNOLOGY CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A load driving circuit, comprising:
an output amplifier, having a push-pull output-stage formed by a first output-stage transistor and a second output-stage transistor having different conductivity types, and outputting an output current output from the push-pull output-stage to a load; and
a detection circuit, detecting a change of the output current,
wherein the detection circuit comprises:
a coupling circuit, respectively generating a first current and a second current that are mirror currents with respect to a current flowing in one of the first output-stage transistor and the second output-stage transistor, respectively generating a third current and a fourth current that are mirror currents with respect to a current flowing in an other of the first output-stage transistor and the second output-stage transistor, coupling the first current and the third current at a first output node to output a voltage generated at the first output node as a first voltage, and coupling the second current and the fourth current at a second output node to output a voltage generated at the second output node as a second voltage;
wherein the coupling circuit respectively generates the first to fourth currents, so that, in a reference state in which the output current is stable within a predetermined range, the third current is greater than the first current and the second current is greater than the fourth current, and
wherein the detection circuit detects, based on the first voltage and the second voltage output from the coupling circuit, whether the output current is changed from the reference state or not.