Title:
TRANSCONDUCTANCE AMPLIFIERS
Document Type and Number:
WIPO Patent Application WO2004025827
Kind Code:
A3
Abstract:
The invention relates to transconductance amplifiers in which an output current depends upon the difference between two input voltages, and to the application of such transconductance amplifiers in analogue-to-digital converters. A difference amplifier (300) is configured for providing an output current dependent upon a difference between a first input voltage (302) and a second input voltage (304). The difference amplifier comprises an input sampling capacitor (318) coupled to a first conductor of said input sampling capacitor and a current output (314) for generating said output current; and an input switch (308, 310) for selectively coupling a second conductor of said input sampling capacitor to a first input of said difference amplifier for receiving said first input voltage and to a second input of said difference amplifier for receiving said second input voltage. The difference amplifier is configured to, in a first state, couple said second conductor to one of said first and second inputs and apply a voltage to said first conductor and to, in a second state, couple said second conductor to the other of said first and second inputs to provide a voltage change to said transconductance amplifier input dependent upon said difference between said first and second input voltages.
Inventors:
GRANVILLE EDWARD MAUGER
Application Number:
PCT/GB2003/003941
Publication Date:
July 01, 2004
Filing Date:
September 10, 2003
Export Citation:
Assignee:
WOLFSON LTD (GB)
International Classes:
H03F3/00; H03F3/45; H03M1/36; H03M1/16; (IPC1-7): H03F3/00
Foreign References:
| US4404525A | 1983-09-13 | |||
| US6011433A | 2000-01-04 | |||
| FR2604835A1 | 1988-04-08 | |||
| US6150851A | 2000-11-21 | |||
| US6169427B1 | 2001-01-02 |
Other References:
BILHAN H ET AL: "A 13 bit 20 Ms/s current mode pipelined analog to digital converter", 1999 IEEE, vol. 1, 8 August 1999 (1999-08-08), pages 186 - 189, XP010510604
FONG K L ET AL: "A 10 bit semi-automatic current mode DAC", PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS. (ISCS). CHICAGO, MAY 3 - 6, 1993, NEW YORK, IEEE, US, vol. 2, 3 May 1993 (1993-05-03), pages 978 - 981, XP010115264, ISBN: 0-7803-1281-3
FONG K L ET AL: "A 10 bit semi-automatic current mode DAC", PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS. (ISCS). CHICAGO, MAY 3 - 6, 1993, NEW YORK, IEEE, US, vol. 2, 3 May 1993 (1993-05-03), pages 978 - 981, XP010115264, ISBN: 0-7803-1281-3
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