BV<sub>CER</sub> - Increased Operating Voltage for SiGe HBTs

Abstract

SiGe-heterojunction bipolar transistors (HBTs) still sustain their leading RF-application position due to their good noise and HF properties. They also offer a relatively high operating voltage, which is limited by BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CEO</sub> , the emitter collector breakdown voltage with open base. We show that BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CER</sub> , the avalanche breakdown with a resistor RB connected to the base, can be used to define reliable operating conditions exceeding BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CEO</sub> . The measured BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CER </sub> data correlate very well with values calculated from basic transistor parameters and their corresponding multiplication factor data. The functionality of this concept is verified by investigating a power amplifier circuit used at emitter collector voltages exceeding BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CEO</sub> in operational mode enabling significant higher output power