| 摘要 |
A circuit for protecting an electronic device including a differential nulling avalanche clamp circuit ( 200, 300 ) and method of using the circuit in an electronic system ( 100 ) to limit radio frequency overdrive. The electronic system ( 100 ) includes a surge clamp ( 130 ) coupled to dissipate an electrical surge effect of a first frequency from a noise sensitive node ( 140 ) and a ring wave clamp ( 120 ) coupled to dissipate an electrical surge effect of a second frequency from the noise sensitive node ( 140 ). The ring wave clamp circuit ( 200, 300 ) includes a first bipolar junction transistor ( 210, 310 ), a second bipolar junction transistor ( 220, 320 ) coupled to the first bipolar junction transistor ( 210, 310 ), and a resistive circuit ( 230, 330, 340 ) coupled to the first and second bipolar junction transistors ( 210, 220, 310, 320 ). A method of using the electronic system ( 100 ) in a device to limit radio frequency overdrive includes the steps of driving an output node with the radio frequency signal subject to overdrive effects ( 410 ), clamping a first order overdrive effect on a first node using a first clamp circuit ( 420 ), and clamping a second order overdrive effect on the first node using the differential nulling avalanche clamp circuit ( 430 ).
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