Taiwan Semiconductor Manufacturing Comp. Ltd.

TSMC China Company Limited

Zhen Tang

Lei Pan

Miranda Ma

A circuit includes a reference node having a reference voltage level, a first node that carries an input signal having a first voltage level or the reference voltage level, a second node that carries a power supply voltage, a voltage regulator including a source follower that outputs a gate signal having a fractional value of the input signal, a first control circuit that selects the higher of the power supply voltage or the gate signal as a first control signal, a second control circuit that selects the higher of the input signal or the first control signal as a second control signal, and first and second transistors coupled in series between the first node and the reference node and configured to receive the first and second control signals.

Failsafe circuit, layout, device, and method

In a method of operating a circuit, at a beginning of a first edge of a driving signal, a first transistor is turned ON to pull, at a first changing rate, a voltage of the driving signal on the first edge from a first voltage toward a second voltage. Then, in response to the voltage of the driving signal on the first edge reaching a threshold voltage between the first voltage and the second voltage, the first transistor is turned OFF and an output circuit is caused to start a second edge of an output signal in response to the first edge of the driving signal. The second edge has a slew rate corresponding to a second changing rate of the voltage of the driving signal on the first edge from the threshold voltage toward the second voltage. The second changing rate is smaller than the first changing rate.

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Hsinchu, Taiwan

Zhen Tang