Title:
BIAS CURRENT CONTROLLER
Document Type and Number:
Japanese Patent JP3398907
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a bias current controller that simply sets a bias current of an output stage transistor(TR) and controls the bias voltage so as not to cut-off the output stage TR.
SOLUTION: Collector currents of positive and negative output stage TRs 15, 16 of a power amplifier 10 are detected and a bias control circuit 600 controls the bias voltage so that the smaller detection current is not smaller than a set current, resulting that the bias current of the output stage TRs is set and the output stage TRs are operated without being cut off. Furthermore, the current is set less dependent on the temperature thereby reducing the temperature dependency of the bias current.
Inventors:
Yasuhiro Amano
Application Number:
JP13001696A
Publication Date:
April 21, 2003
Filing Date:
May 24, 1996
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H03F1/30; H03F3/20; H03F3/30; (IPC1-7): H03F1/30; H03F3/20; H03F3/30
Domestic Patent References:
| JP786843A | ||||
| JP58143611A | ||||
| JP865061A | ||||
| JP5910010A | ||||
| JP63283308A |
Attorney, Agent or Firm:
Mitsuyama Murayama (1 person outside)