Analyses and design of bias circuits tolerating output voltages above BVCEO

Due to the inevitable tradeoff between speed and breakdown voltage, the spectacular speed improvement of modern SiGe processes in recent history has partially been achieved at the cost of a reduction in breakdown voltages. Because supply voltages have hardly been reduced however, circuits operating at a supply voltage above the collector-emitter breakdown voltage (BVCEO) are common practice today and collector-base avalanche currents are therefore of major concern.