Title:
EXPONENTIAL CONVERTING CIRCUIT AND VARAIBLE GAIN CIRCUIT USING IT
Document Type and Number:
Japanese Patent JP3748371
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize a stable exponential gain control independent from fluctuation of element characteristic.
SOLUTION: In a master block (first exponential converting circuit) 302, an exponential converting characteristic is determined on the basis of an in- phase reference voltage Vcom1 and a reference voltage Vcom2. In a slave block (second exponential converting circuit) 303, a control voltage Vc and a gain control signal ln (Icont) are generated by use of the exponential converting characteristic determined by the master block 302 on the basis of the in-phase reference voltage Vcom1 and a reference voltage Vcom3. The gain of a variable gain amplifier, for example, is controlled by use of this gain control signal ln (Icont).
Inventors:
Kano Shuo
Takafumi Yamaji
Tetsuro Itakura
Takafumi Yamaji
Tetsuro Itakura
Application Number:
JP2000280829A
Publication Date:
February 22, 2006
Filing Date:
September 14, 2000
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
G06G7/24; H03G3/00; H03G3/10; H03G7/06; (IPC1-7): G06G7/24; H03G3/10
Domestic Patent References:
| JP7122950A | ||||
| JP5506140A |
Attorney, Agent or Firm:
Takehiko Suzue
Sadao Muramatsu
Atsushi Tsuboi
Ryo Hashimoto
Satoshi Kono
Makoto Nakamura
Shoji Kawai
Sadao Muramatsu
Atsushi Tsuboi
Ryo Hashimoto
Satoshi Kono
Makoto Nakamura
Shoji Kawai