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.
• Download:

  IMEKO-TC4-2008-149.pdf
• DOI:

  _unreg_tc4-2008.149

Event details:

• IMEKO TC:

  TC4
• Event name:

  Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
• Title:

  XVIth IMEKO TC4 International Symposium on Electrical Measurements and Instrumentation (together with 13th IMEKO TC4 Workshop on ADC Modelling and Testing)
• Place:

  Florence, ITALY
• Time:

  22 September 2008 - 24 September 2008