Semiconductor device

摘要

A semiconductor device using analog-to digital (AD) conversion realizes reliable control so that, at the time of AD converting reference voltage, a low-voltage transistor in a reference voltage generating circuit is not destroyed by voltage held in a sample and hold circuit. In a semiconductor device, when an instruction of detecting a reference voltage value is received, a switch control unit controlling switching of an input signal of an internal AD converter temporarily automatically couples an input node of a sample and hold circuit and a ground node and, after that, couples the input node of the sample and hold circuit and an output node of a reference voltage generating circuit.

主权项

1. A semiconductor device comprising:
a sample and hold circuit; an AD converter for AD (Analog-to-Digital) converting an output of the sample and hold circuit; a signal terminal for receiving an analog signal; a reference voltage generating circuit for generating and outputting a reference voltage; a first switch electrically coupling the signal terminal to the input node of the sample and hold circuit, a second switch electrically coupling the ground node to the input node of the sample and hold circuit, and a third switch electrically coupling the output node of the reference voltage generating circuit to the input node of the sample and hold circuit; and a switch control unit for controlling the first to third switch, the switch control unit generating a first control signal (END) for turning on the second switch and generating, based on the first control signal, a second control signal (DQ) for turning on the third switch.