Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
296 words
A multistage differential amplifier having improved drift compensating means comprising: a pair of signal input terminals; a pair of signal output terminals; positive and negative current supply terminals adapted to be connected to an electrical energy source; an input differential amplifier stage comprising a pair of common emitter transistors, each transistor having having a base and an emitter and a collector, the bases being individually coupled to said input terminals, a potentiometer, having end terminals connected to said collectors and an adjustable terminal connected to said positive supply terminal, for providing collector loads for said transistors, a pair of emitter load networks for said transistors, said emitter networks being connected to said negative current supply terminal, gain determining resistor connected between junction points on said emitter load networks, one of said emitter load networks including, between its respective junction point and its respective emitter, a resistor having a temperaure coefficient proportioned to compensate for drift, and additional amplifier stage means intercoupled between said collectors and said output terminals, said additional amplifier stage means comprising a pair of common-collector transistors each having a base and an emitter and a collector, collector load resistors in series between the collectors of the common-collector transistors and the negative supply terminals, a parallel resistance-capacitance, filter network between both emitters of the common-collector, transistors and said positive current supply terminal, and series resistance-capacticance biasing networks between the bases and collectors of said common-collector transistors, said additional amplifier stage means further including a pair of field-effect transistors having their gates connected to the collector of the common-collector transistors and their sources connected across said balancing resistor to provide degenerative feedback current means and their sources connected directly to said output terminals and individual load resistors between said drains and said positive supply terminal.
Claim 2
Dependent Claim
296 words
A multistage differential amplifier having improved drift compensating means comprising: a pair of signal input terminals; a pair of signal output terminals; positive and negative current supply terminals adapted to be connected to an electrical energy source; an input differential amplifier stage comprising a pair of common emitter transistors, each transistor having having a base and an emitter and a collector, the bases being individually coupled to said input terminals, a potentiometer, having end terminals connected to said collectors and an adjustable terminal connected to said positive supply terminal, for providing collector loads for said transistors, a pair of emitter load networks for said transistors, said emitter networks being connected to said negative current supply terminal, gain determining resistor connected between junction points on said emitter load networks, one of said emitter load networks including, between its respective junction point and its respective emitter, a resistor having a temperaure coefficient proportioned to compensate for drift, and additional amplifier stage means intercoupled between said collectors and said output terminals, said additional amplifier stage means comprising a pair of common-collector transistors each having a base and an emitter and a collector, collector load resistors in series between the collectors of the common-collector transistors and the negative supply terminals, a parallel resistance-capacitance, filter network between both emitters of the common-collector, transistors and said positive current supply terminal, and series resistance-capacticance biasing networks between the bases and collectors of said common-collector transistors, said additional amplifier stage means further including a pair of field-effect transistors having their gates connected to the collector of the common-collector transistors and their sources connected across said balancing resistor to provide degenerative feedback current means and their sources connected directly to said output terminals and individual load resistors between said drains and said positive supply terminal.