Title:
TEMPERATURE COMPENSATED R-C OSCILLATOR
Document Type and Number:
WIPO Patent Application WO2004055968
Kind Code:
A3
Abstract:
An R-C oscillator (200) is configured to vary the two voltage levels that are used to control the oscillation, such that the variation in oscillation frequency with temperature is minimized. A first resistor (R1) is used to control one of the voltage levels, and a second resistor (R2) having a temperature coefficient that differs from the temperature coefficient of the first transistor is used to control the other voltage level. The first resistor (R1) also controls the current used to charge and discharge the capacitor (C) used to effect the oscillation. By the appropriate choice of resistance values, the variations of the control voltages and current are such that the time to charge and discharge the capacitor (C) between the control voltages remains substantially constant with temperature. Preferably the resistance values are selected to also compensate for temperature variations in the delay of the feedback loop.
Inventors:
YARBOROUGH JOHN M JR (US)
Application Number:
PCT/IB2003/005979
Publication Date:
November 25, 2004
Filing Date:
December 15, 2003
Export Citation:
Assignee:
KONINKL PHILIPS ELECTRONICS NV (NL)
YARBOROUGH JOHN M JR (US)
YARBOROUGH JOHN M JR (US)
International Classes:
H03K3/011; H03K3/0231; (IPC1-7): H03K3/011
Foreign References:
| US6300843B1 | 2001-10-09 | |||
| US20020067215A1 | 2002-06-06 | |||
| US5448103A | 1995-09-05 | |||
| US6326859B1 | 2001-12-04 | |||
| US5969557A | 1999-10-19 | |||
| JP2001267888A | 2001-09-28 | |||
| GB1515574A | 1978-06-28 | |||
| US4677315A | 1987-06-30 |
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