2009 Volume 6 Issue 23 Pages 1663-1668
A bridge resistance deviation-to-period (BRD-to-P) converter is presented for interfacing resistive sensor bridges. It consists of a linear operational transconductance amplifier (OTA) and a current-controlled oscillator (CCO) formed by a current-tunable Schmitt trigger and an integrator. The free running period of the converter is 1.824ms when the bridge offset resistance is 1kΩ. The conversion sensitivity of the converter amounts to 3.814ms/Ω over the resistance deviation range of 0-1.2Ω. The linearity error of the conversion characteristic is less than ±0.004%.