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US 4,573,021 AGranted
Circuit output stage arrangement
OwnerRobert J. Widlarinventor
Life of this patent
Estimating the term…
Abstract
A circuit arrangement including first and second output transistors, a sensor diode means, and a circuit means. The first output transistor drives the load positive. The second output transistor drives the load negative. The sensor diode means senses the current in the collector of the first output transistor. The circuit means is connected in circuit with the sensor diode means and the base of the second output transistor for establishing the quiescent current level of the first output transistor. An output of the circuit means is applied at the base of the second output transistor for preventing the output of the first output transistor from falling substantially below its quiescent current level. The output of the circuit means is dependent upon the current sensed by the sensor diode means.
Claims29
A circuit output stage, comprising:
- a first output transistor wherein an input to the circuit is to be applied to the base of said first output transistor;
- a second output transistor having its collector connected to the emitter of said first output transistor wherein an output from the circuit is to be taken from the junction of said collector and emitter;
- a first diode means for sensing the current flow in the collector of said first output transistor;
- and
- a circuit means for establishing a quiescent operating current level of said first output transistor and said circuit means having an output that is to be applied to the base of said second output transistor for preventing the output of said first output transistor from falling substantially below said quiescent operating current level wherein the output of said circuit means is dependent upon the current sensed by said first diode means.
2 more elements
A circuit, comprising:
- a first output transistor means for supplying a positive output load current wherein an input to the circuit is to be applied to the base of said first output transistor means;
- a second output transistor means for supplying a negative output load current having its collector connected with the emitter of said first output transistor means wherein an output from the circuit is to be taken from the junction of said collector and emitter;
- a first diode means connected with the collector of said first output transistor means for sensing the current flow therein;
- a circuit means connected with said first diode means and the base of said second output transistor means for establishing a quiescent current level for said first output transistor means;
- and
- said circuit means having an output that is dependent upon the current sensed by said first diode means wherein the output is to be applied at the base of said second output transistor means to cause said second output transistor means to supply the negative output load current and to prevent the output of said first output transistor means from falling substantially below said quiescent current level.
3 more elements
A circuit output stage, comprising:
- a first output transistor wherein an input to the circuit is applied at the base of said first output transistor;
- a second output transistor having its collector connected with the emitter of said first output transistor wherein an output from the circuit is taken from the junction of said collector and emitter;
- a sensor diode means for sensing the current flow in the collector of said first output transistor;
- a reference diode means for establishing a reference voltage;
- a circuit means for establishing a quiescent current level of said first output transistor;
- and
- said circuit means having an output that is a function of said reference voltage and a voltage across said sensor diode means wherein said output is applied to the base of said second output transistor to cause said second output transistor to supply a negative output load current and to prevent the output of said first output transistor from dropping substantially below its quiescent current level.
4 more elements
A circuit output stage arrangement, comprising:
- p1 a first output transistor for supplying a positive output load current wherein an input signal is applied to the base of said first output transistor;
- a second output transistor for supplying a negative output load current having its collector connected to the emitter of said first output transistor wherein an output from the circuit is taken from the junction of said collector and emitter;
- a first diode means connected with the collector of said first output transistor for sensing the current flow in the collector;
- a second diode means for establishing a reference voltage from a known reference current;
- a circuit means for establishing the quiescent current of said first output transistor;
- and
- said circuit means having an output that is a function of said reference current and the current sensed by said first diode means wherein said output is applied to the base of said second output transistor to cause said second output transistor to supply the negative output load current and to prevent the output of said first output transistor from dropping substantially below said quiescent current level.
4 more elements
Dependencies are inferred from the claim text.