Patent ID: 8067953

Claim:
A semiconductor device for measuring ultra low currents or voltages, comprising: a first and a second voltage supply terminal, an input terminal for receiving an electrical current or being supplied with a voltage to be measured, a bipolar transistor having a base, an emitter and a collector, wherein a first PN junction is formed between the base and the collector and a second PN junction is formed between the base and the emitter, wherein the emitter is coupled to the input terminal and the base is coupled to the second voltage supply terminal, wherein the first PN junction is designed for reverse biased operation as an avalanche diode and wherein a leakage current of the first PN junction is smaller than 10 −15 A, and a quenching and recharging circuit having a first terminal coupled to the first voltage supply terminal and a second terminal coupled to the collector of the bipolar transistor, the quenching and recharging circuit permitting operation of the first PN junction reverse biased above the breakdown voltage of the first PN junction.