Load drive circuit, electronic control device, and control method for electronic control device

Abstract

Provided are a highly reliable load drive circuit that includes a switching circuit that selects a power supply voltage, and is capable of seamlessly switching the power supply voltage without using a switch or a determination circuit, an electronic control device using the load drive circuit, and a control method for the electronic control device. The load drive circuit includes: a booster circuit that boosts an output from a power supply; and a voltage switching circuit that switches the output from the power supply and an output from the booster circuit, in which the voltage switching circuit includes a first MOSFET, a second MOSFET, and a gate voltage generation circuit that generates gate voltages of the first MOSFET and the second MOSFET, gate terminals of the first MOSFET and the second MOSFET are connected to the gate voltage generation circuit, source terminals of the first MOSFET and the second MOSFET are connected to the same node, a drain terminal of the first MOSFET is connected to an output terminal of the booster circuit, a drain terminal of the second MOSFET is connected to an output terminal of the power supply, and the output from the power supply and the output from the booster circuit are seamlessly switched according to an output voltage from the power supply.