摘要 |
An ESD protection circuit having a high triggering threshold. The ESD protection circuit comprises a semiconductor-controlled rectifier (SCR) and a bipolar-junction-transistor (BJT). The SCR comprises an anode, an anode gate, a cathode gate and a cathode. The anode is coupled to a first pad. The cathode gate and the cathode are coupled to a second pad. The BJT transistor is parasitic under a metal-on-semiconductor (MOS) transistor and has a collector and an emitter. Either the collector or the emitter is coupled to the anode gate, and the other is coupled only to the second pad. Current generated at the anode is shared by the BJT transistor. A larger current is required to trigger the SCR in the ESD protection circuit of the present invention and result in a latch-up. Thus, latch-up caused by accidental noise is prevented during normal power operations.
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