Patent ID: 6118301
Filing Date: 2000-09-12
Classification: G06F,H03K

Abstract:
A high voltage tolerant and compliant driver circuit for interfacing between a digital input and an output line, comprising:an input stage that is connected to receive an input digital signal which may be DRIVE HI or DRIVE LO, and operates from an input power supply to produce a switching signal,an output stage that is connected to receive said switching signal and operates from an output power supply, which may be different from said input power supply, to produce an output signal that corresponds to the input signal and has a HI state set by an output power supply, andan output line connected to receive said output signal, said output line being subject to receiving other signals which may differ from said output power supply,said output stage comprising:an output power supply terminal for receiving a voltage from an output power supply,a pair of switches having respective current circuits connected in series between said output power supply terminal and said output line, and respective control terminals which turn their respective current circuits ON or OFF in response to applied control voltages,a control circuit which turns both of said switches ON in response to a DRIVE HI input signal, anda third switch which connects said output line to a ground terminal in response to a DRIVE LO input signal,wherein said control circuit turns at least one of said switches OFF in response to a DRIVE LO input signal, regardless of whether the voltage on said output line equals or differs from the voltage on said output power supple terminal.