Semiconductor circuit and semiconductor apparatus

Patent metadata

Field	Value
Publication number	US-9306554-B2
Application number	US-201313864328-A
Country	US
Kind code	B2
Filing date	Apr 17, 2013
Priority date	Apr 20, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A semiconductor circuit includes an operational amplifier, a voltage drop circuit, and a switch. The operational amplifier has an output terminal connected to an active element that produces a load drive current. A reference voltage is input to the non-inverting input of the operational amplifier. The voltage drop circuit drops a voltage outputted from the operational amplifier. The switch applies a voltage corresponding to a predetermined current flowing when the active element is on to the inverting input of the operational amplifier in a first interval in which the active element is on in response to a predetermined voltage from the operational amplifier. The switch allows the voltage dropped by the voltage drop circuit to be input to the inverting input in a second interval in which the active element is off, thereby shortening a time period until the load drive current starts to flow.

First claim

What is claimed is:

1. A semiconductor circuit that controls driving of a first load, the semiconductor circuit comprising:
an operational amplifier that includes a first input terminal, a second input terminal, and an output terminal, and that outputs a first voltage from the output terminal;
a voltage drop circuit which drops the first voltage and generates a second voltage; and
an input switching part configured to input a third voltage to the second input terminal during a…

Assignees

• Lapis Semiconductor Co Ltd

Inventors

• Katoh Teruo

Classifications

• H05B45/44

  Electricity · mapped topic

• H03K17/063

  Electricity · mapped topic

• H05B33/0818

  Electricity · mapped topic

• H03K17/00 Primary

  Electricity · mapped topic

• H03K17/145 Primary

  Electricity · mapped topic