Gated lateral bipolar transistors: characteristics, modeling and applications

The technology, physics, electrical characteristics (particularly at low temperatures) and analog circuit applications of a new gated lateral pnp (LPNP) bipolar transistor, fabricated with a 0.8 μm BiCMOS technology, are described. This gated LPNP transistor has five terminals-collector, base, emitter, gate and substrate. Because there are two inputs (gate and emitter for a common-base configuration, or gate and base for a common-emitter configuration) and one output (collector), the transistor shows unique dc characteristics of variable current gain β_F of 10²~10⁶ with V _G variations of 0.4 to -0.4 V; variable transconductance g _M which increases 3~10 times as V_E increases from 0.4 to 0.7 V. The low temperature characteristics of this GLPNP in both gate-emitter shorted and gate-base shorted configurations are investigated in detail in the range between 300 K and 77 K. This new device is very suitable for analog circuit applications; for example, when used as a mixer at 300 K, it has conversion gain of 5 to 12 dB for input RF signals up to 400 MHz