SIGNAL TO NOISE RATIO IMPROVEMENT BY POWER SUPPLY VOLTAGE SWITCHING
Abstract
AC excitation followed by synchronous demodulation is an effective noise-reduction method for signal conditioning in modulating sensors. However, it cannot be applied to self-generating sensors such as thermocouples or piezoelectric films. Switching on and off the power supply voltage of an amplifier yields a modulated output signal and allows for synchronous demodulation. Hence, this method improves the signal-to-noise ratio (SNR) by reducing 1/f noise and reduces power consumption. Furthermore, it can be applied to self-generating sensors. A prototype system based on this method has been applied to a thermocouple signal conditioner whose power supply voltage was switched at 1 kHz. The nonlinearity error obtained was below 0.01 FSR and the SNR was 90 dB for a 1.5 Hz noise bandwidth.
Event details
- Event
- Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
- Technical Committee
- TC4
- Place
- Florence, ITALY
- Time
- 22 September 2008 - 24 September 2008
- Website
- http://www.imeko2008.org/