Phase Splitter with Controlled Common Mode Level
Original Publication Date: 1978-May-01
Included in the Prior Art Database: 2005-Feb-21
In Fig. 1 a phase splitter 1 receives a single-ended input from terminal 2 via amplifier 3 and line 4. The phase splitter provides differential outputs on lines 5 and 6 to drive current bidirectionally through a load, such as an electric motor, by means of transistors Q(3)-Q(6) which are connected in a bridge configuration. The two phases are applied to transistors Q(1) and Q(2) to control the direction of current through the load. A common problem in such a circuit is to maintain the transistors Q(3)-Q(6), during the quiescent state, just below their threshold of conduction, thereby avoiding crossover distortion, without allowing a short through Q(3), Q(5) or Q(4), Q(6) as the conduction threshold varies with ambient temperature.