ESD protection devices and methods

摘要

Various embodiments described below relate to an ESD protection device that includes a voltage controlled shunt (e.g., a transistor) to selectively shunt energy of an incoming ESD pulse away from a circuit that includes a semiconductor device to be protected. In some embodiments, the ESD protection device includes a power up detection element to determine whether the circuit has powered up. If the circuit is powered up, the power up detection element prevents inadvertent triggering of the ESD protection device.

主权项

1. An electrostatic discharge (ESD) protection device to protect a circuit coupled to first and second circuit nodes from an ESD event, the ESD protection device comprising:
a first electrical path extending between the first and second circuit nodes and including a voltage controlled shunt thereon, the voltage controlled shunt having a control terminal to control an amount of energy shunted over the first electrical path via the voltage controlled shunt; a power up detection element comprising an input coupled to the circuit, and an output coupled to the control terminal of the voltage controlled shunt; a second electrical path in parallel with the first electrical path and including an ESD detection element thereon; and a voltage bias element having first and second inputs coupled to the power up detection element and the ESD detection element, respectively, and having an output coupled to the control terminal of the voltage controlled shunt, wherein the voltage bias element comprises:
a timing pulse generator coupled to the ESD detection element and configured to provide a shunt control signal having a predetermined duration based on whether the ESD detection element detects an ESD pulse; anda noise immunity circuit to disable the energy transfer over the first electrical path based on whether the power up detection element detects the circuit is powered up; wherein the power up detection element receives a signal different than signals at the first and second circuit nodes from the circuit, monitors a voltage of the signal to determine whether the circuit is powered up, and selectively asserts a power-up signal at the output based on whether the circuit is powered up; and wherein the voltage controlled shunt controls the amount of energy shunted over the first electrical path based on the power-up signal.