Title:
AMPLIFIER AND FILTER HAVING VARIABLE GAIN AND CUTOFF FREQUENCY CONTROLLED LOGARITHMICALLY ACCORDING TO DIGITAL CODE
Document Type and Number:
WIPO Patent Application WO/2013/089446
Kind Code:
A1
Abstract:
A variable gain amplifier circuit is provided. The circuit includes an operational amplifier for amplifying and outputting an input signal according to a cutoff frequency and a gain, a feedback resistor for changing a first resistance according to a first digital control code value which determines the cutoff frequency, and an input resistor for changing a second resistance according to a second digital control code value which is determined based on a difference of the first digital control code value and a gain code value. The gain is determined by a ratio of the first resistance and the second resistance and linearly changes on a decibel (dB) basis according to the first digital control code value, the cutoff frequency is inversely proportional to the first resistance and linearly changes on a log scale, and the variable gain can be easily set using the control code.
Inventors:
LEE JONG-WOO (KR)
Application Number:
PCT/KR2012/010824
Publication Date:
June 20, 2013
Filing Date:
December 13, 2012
Export Citation:
Assignee:
SAMSUNG ELECTRONICS CO LTD (KR)
International Classes:
H03G3/20; H03H11/12
Foreign References:
| US20030058048A1 | 2003-03-27 | |||
| US20090039955A1 | 2009-02-12 | |||
| US20080197924A1 | 2008-08-21 | |||
| US20070296490A1 | 2007-12-27 |
Other References:
See also references of EP 2792071A4
Attorney, Agent or Firm:
KWON, Hyuk-Rok et al. (Jongro-gu, Seoul 110-062, KR)
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Claims: