Sang-Hee Son

A Resistance Deviation-to-Pulsewidth Converter for Resistive Sensors

A resistance deviation-to-pulsewidth converter is presented for interfacing resistive sensors. It consists of a ramp integrator, two resistance-tunable Schmitt triggers, and two logic gates. A prototype circuit built using discrete components exhibits a resolution as high as 14 bits and a linearity error less than plusmn0.06% when the output pulse is counted by a 10-MHz clock signal. The proposed circuit is applied to measure the temperature difference with the platinum resistance temperature detectors. The measured conversion sensitivity of the temperature difference-to-pulsewidth converter is 5.74 mus/degC, and its linearity error is less than plusmn1% in the temperature difference range of 0degC to 100degC.

A bridge resistance deviation-to-time interval converter for resistive sensor bridges

A bridge resistance deviation-to-time interval converter is presented for interfacing resistive sensor bridges. It consists of two voltage-to-current converters, two current-tunable Schmitt triggers, a ramp integrator, and two logic gates. A prototype circuit built using discrete components exhibits a conversion sensitivity amounting to 4527.8µs/Ω over the resistance deviation range of 0-2Ω and a linearity error less than ± 0.01%.

A simple resistance-to-time converter for resistive bridge sensors

A simple resistance-to-time converter is presented for interfacing resistive bridge sensors. It consists of two voltage comparators, a ramp voltage generator, and two logic gates. A prototype circuit built using discrete components exhibit a conversion sensitivity amounting to 2832.4μs/Ω over the resistance deviation range of 0-2Ω and a linearity error less than 0.005%. Power dissipation of the converter is 15.57mW.

A Resistance Deviation-To-Time Interval Converter Using Second Generation Current Conveyors

A resistance deviation-to-time interval converter using second generation current conveyors is designed for connecting resistive bridge sensors with a digital system based on dual-slope integration. Simulation results exhibit that a conversion sensitivity amounts to 15.56 μs/Ω over the resistance deviation range of 0-200 Ω and its linearity error is less than ±0.02%. Its temperature stability is less than 220 ppm/℃ in the temperature range of −25-85℃.

A Bipolar Linear Transconductor Using Translinear Cells and Its Application

A novel linear transconductor using translinear cells is proposed. It consists of a voltage follower, a resistor, and a current follower. SPICE simulations using an 8 GHz bipolar transistor-array parameter show that the linear transconductor with a transconductance of 1 mS exhibits a linearity error of less than ±0.75% over an input voltage range of ±1 V for a supply voltage of ±2.0 V. The temperature coefficient of the transconductance is less than 124 ppm/°C. The -3-dB frequency of the transconductance is more than 4.5 GHz. Applying the linear transconductor as a building block, the design of a bandpass filter with center frequency of 85 MHz and Q-factor of 80 is presented.