Ota-based first-order filter designs and oscillator application

In this study, first order filter configurations and oscillator is designed to process electronic signals. Simulations and circuit applications of the proposed designs are realized. Since it is important to use as few circuit elements as possible in analog circuit designs, operational transconductor amplifier (OTA) active structural block is preferred. In the study, first-order current-mode universal filter consisting of two OTA's is designed. Since the filter is current input and current output, it consumes less power than its equivalents in different modes. The cut-off frequency (fo) of the filter is 150 kHz and power consumption is 1.04 mW. In the second study, a first-order voltage mode low-pass filter using two OTA's is designed. The gain of the filter is adjustable. The (fo) is 1.59 MHz and power consumption is 1.03 mW. In the third study, an OTA-based transimpedance-mode universal filter consisting of three OTA's that can produce all the filter responses simultaneously is designed. The (fo) of the filter is 3 MHz and power consumption is 1.55 mW. Since there are no floating elements in the transimpedance and current-mode filters, they are suitable for integrated circuit structure. The sinusoidal quadrature oscillator circuit is derived from the transimpedance-mode filter topology. Oscillating frequency of the oscillator is 3.97 MHz and power consumption is 1.95 mW. In the study, three first-order filters operating in different modes were designed. Supply voltages are ±0.75 V and transistor technology is 0.18 µm. Theoretical results of the studies verified with the SPICE and the experiment.