BICMOS-TREIBERSCHALTUNG

摘要

A BiCMOS driving circuit includes a logic unit 31 for converting an input signal to a logic level, a high current driving unit 33 for driving the logic level with high current and formed of bipolar devices, and a speed improving logic unit 32 interposed between the logic unit 31 and high current driving unit 33 and formed of devices having a high input-impedance characteristic, for reducing the discharge time of the high current driving unit. By the use of CMOS inverter in the speed improving logic unit 32 instead of a conventional resistor which occupies greater chip area, the circuit is favourable for achieving high density of a semiconductor device. Since the discharge path of a transistor is formed by a MOS device having a high input impedance, the discharge time constant is decreased, thereby quickening the discharge speed which in turn greatly improves the operational speed of the circuit. In a modification (Fig 4B) instead of connecting the input of the logic unit 32 to the input of the logic unit 31 the input of the logic unit 32 is connected to the input of the logic unit 31. <IMAGE>