Circuit arrangement for protection from electrostatic discharges and method for operating same

摘要

A circuit arrangement for protection against electrostatic discharges has a diverting structure (ESD1), which comprises a diverting element (DE1) and a switchable element (SW1). The diverting element (DE1) is set up to drain off an electrostatic discharge between a first and a second terminal (K1, K2). The switchable element (SW1) can take a first and a second switching state, where a function of the diverting element (DE1) can be activated depending on the switching state of the switchable element (SW1).

主权项

1. A circuit arrangement for protection against electrostatic discharges comprising:
a first diverting structure with a first diverting element and a first switchable element; a second diverting structure with a second diverting element; and a control circuit configured to determine an operating state of the circuit arrangement by evaluating an average potential difference between a first and a second terminal; wherein the first diverting element is configured to drain off an electrostatic discharge between the first and the second terminal and comprises an element with a voltage-current characteristic curve that has voltage snapback; wherein the first switchable element is adapted to take on a first switching state and a second switching state, with a diverting function of the first diverting element being activated by the first switching state of the first switchable element and deactivated by the second switching state of the first switchable element; wherein a series circuit of the first diverting element and the first switchable element connects the first terminal to the second terminal; wherein the control circuit is configured to control the relevant switching state of the first switchable element depending on the determined operating state; wherein the second diverting element connects the first terminal to the second terminal directly or via a series connection of the second diverting element and a second switchable element, is configured to drain off an electrostatic discharge between the first and the second terminal, and comprises at least one of the following: a pnp transistor; a p-channel field effect transistor; a Zener diode; or an element with a voltage-current characteristic curve that does not have voltage snapback; and wherein the first diverting element and the second diverting element are configured to drain off electrostatic discharge such that the first and second diverting elements do not interact with each other during a respective electrostatic discharge event, and wherein the first switchable element is a one-time switchable element.