Title:
PUSH-PULL OUTPUT CIRCUIT AND OPERATIONAL AMPLIFIER
Document Type and Number:
Japanese Patent JP3906711
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a push-pull output circuit and an operational amplifier configured with the same capable of suppressing an increase in consumed current and an increase in crossover distortion even when an operating state is changed.
SOLUTION: The operational amplifier 21 comprises a differential amplifier circuit 22 and a complementary push-pull output circuit 23, and a current supply circuit 30 is connected between a power line 24 and a collector of a transistor Q31 in the output circuit 23. Most of currents in excess of a prescribed current in a differential current between a constant current outputted from the transistor Q31 and a base current of a transistor Q50 flow to a parallel circuit consisting of transistors Q53, Q54. Thus, even when an output current Io is fluctuated, a collector current of a transistor Q52, and then a base-emitter voltage are controlled to be constant so as to maintain a voltage across a resistor R32 to be a voltage close to 0 V to the utmost. As a result, an idling current flowing through the transistors Q49, Q50 and crossover distortion can be suppressed.
Inventors:
Takeshi Miki
Application Number:
JP2002050009A
Publication Date:
April 18, 2007
Filing Date:
February 26, 2002
Export Citation:
Assignee:
株式会社デンソー
International Classes:
H03F3/30; H03F1/02; (IPC1-7): H03F3/30; H03F1/02
Domestic Patent References:
| JP4314206A | ||||
| JP2000091858A | ||||
| JP61105916A | ||||
| JP61108208A | ||||
| JP64004106A |
Attorney, Agent or Firm:
Tsuyoshi Sato
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