Title:
AUTOMATIC GAIN CONTROL CIRCUIT
Document Type and Number:
Japanese Patent JP2723776
Kind Code:
B2
Abstract:
PURPOSE: To obtain an automatic gain control circuit whose operation is made stable by controlling the operation of an AGC control counter with a run/stop instruction given to the AGC control counter.
CONSTITUTION: A peak value 14 held by a sample-and-hold circuit 3 is inputted to comparators 5, 6, in which the peak value is compared respectively with reference values a15, b16. The result of comparison is inputted to a counter 7, which receives a step-up signal 17 from the comparator 5 and a step-down signal 18 from the comparator 6 to act as an up-counter. Furthermore, the counter 7 executes a reset operation when the counter 7 receives other combinations of the outputs of the comparators 5, 6. A run/stop control circuit 8 outputs a run instruction when the count of the counter 7 is 4 or over and outputs a stop instruction when the count is less than 4. The AGC control counter 9 makes amplification factor step revision to the amplifier 1 in the case of the run instruction with a run/stop instruction 19 of the circuit 8 and stops the step revision in the case of the stop instruction.
Inventors:
YUI MIEKO
Application Number:
JP9474193A
Publication Date:
March 09, 1998
Filing Date:
April 22, 1993
Export Citation:
Assignee:
NIPPON DENKI KK
International Classes:
H03G3/20; H03G3/30; H03G5/16; H04B3/06; (IPC1-7): H03G3/20; H03G3/30; H03G5/16; H04B3/06
Domestic Patent References:
| JP60187138A | ||||
| JP3230607A | ||||
| JP380675A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)