Title:
AMPLIFIER
Document Type and Number:
Japanese Patent JPH02164114
Kind Code:
A
Abstract:
PURPOSE: To improve the positive through rate of an amplifier by providing the amplifier with a controllable auxiliary output stage, and when an error signal indicating a large difference between an input signal and an output signal appears, supplying an additional power supply current by the auxiliary output stage. CONSTITUTION: An auxiliary B class output stage 44 consists of a switch FET 46, a 2nd current source FET 48 and a through FET 50. When an error signal applied to the gate of the FET 46 does not exceed a threshold defined by the FET 48, the FET 50 is turned off. When the signal applied to the gate of the FET 46 exceeds the threshold, voltage is impressed to the gate of the FET 50. The FET 50 is turned on and an additional power supply current necessary for the attainment of a high positive through rate is supplied. Since the activated through FET 50 acts so as to compenate a current generated from a load FET 36, the positive through rate is improved.
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Inventors:
NOOMAN JII DEIRUMAN
Application Number:
JP27142689A
Publication Date:
June 25, 1990
Filing Date:
October 18, 1989
Export Citation:
Assignee:
HEWLETT PACKARD CO
International Classes:
H03F3/345; H03F3/30; H03F3/347; H03F3/45; (IPC1-7): H03F3/345
Attorney, Agent or Firm:
Kaoru Furuya (2 outside)