Rohm Co., Ltd.

Yohei Okuno

Naoki Takahashi

Masaki Omi

Muga Imamura

Takayuki Nakashima

A load driving device, wherein a logic portion for switching on/off a switch element connected to a load includes: a switch signal generation circuit for generating a switch signal so that the switch element is left on by default in a time duration from when power is turned on until an external reset release is performed by a microcomputer; an overcurrent protection circuit for performing, after the external reset release, an output restriction of the switch signal so as to forcibly switch the switch element off in response to an overcurrent detection signal; and a latch circuit for performing, in the time duration from when power is turned on until the external reset release is performed by the microcomputer, an output restriction of the switch signal so as to forcibly switch the switch element off with the overcurrent detection signal serving as a latch trigger.

Load driving device

An antenna driving device includes an antenna driving circuit arranged to generate driving current of a transmission antenna, a power supply circuit arranged to generate an output voltage from an input voltage so as to supply the output voltage to the antenna driving circuit, and a logic circuit arranged to control the antenna driving circuit and the power supply circuit. The power supply circuit has a function of temporarily disabling current feedback control so as to perform voltage feedback control using a reference value just before halting the drive of the transmission antenna when the power supply circuit restarts to drive the transmission antenna, or has a function of performing variable control of a reference value for current feedback control in accordance with a rising edge of the driving current when the power supply circuit restarts to drive the transmission antenna.

Growing community of inventors

Kyoto, Japan

Yohei Okuno