Bipolar strobed transistor latch for a high gain comparator

Claim 1

A differential amplifier and latch combination comprising: first and second power supply terminals connectable to a source of operating power; first and second transistors having their emitters coupled together and returned through a first constant current device to said second power supply terminal, their bases coupled to a source of input signal, and their collectors coupled via a cascode load to said first power supply terminal; third and fourth transistors, each having an emitter, a base, and a pair of collector contacts having appreciable resistance therebetween; means coupling the pair of collectors in said third transistor in series between said collector of said first transistor and said cascode load; means coupling the pair of collectors in said fourth transistor in series between said collector of said second transistor and said cascode load; means coupling the emitters of said third and fourth transistors together and to a second constant current device which couples said emitters to said second power supply terminal; means for cross coupling said bases of said third and fourth transistors to the opposing collectors, thereby creating a latch; and means for switching said second constant current device on and off in response to a strobe signal input whereby said third and fourth transistors can be turned on to activate said latch and off to disable said latch.