Sub-300-ps CBL circuits

Advanced charge-buffered-logic (CBL) circuits featuring double-poly self-alignment, a 'free' epi-base lateral p-n-p (cutoff frequency=300 MHz only), and deep trench isolation are discussed. Using 1.2- mu m design rules and a modified push-pull output stage, a gate delay (fan-in=3) of 278 ps was obtained at a DC current of 30 mu A/gate. The low power-delay product underlies the speed and power potential of CBL as an attractive practical approach to bipolar complementary transistor logic.<
>