Second-order OTA-C filters using a single OTA
A new voltage-mode second-order low pass OTA-C filter is proposed. The filter is integrator-based and uses only one OTA and two grounded capacitors. A multiple-input operational transconductance amplifier (OTA) for the simulation of the proposed filter is also described. The filter has been simulated using a 0.25μm CMOS process. The results show that for a cutoff frequency of 50 MHz, the filter dissipates 5.3mW power from a single 2V supply. The dynamic range and RMS noise are 63dB and 91μV (up to 100MHz), respectively. Further advantages of the proposed filter are frequency tunability, low sensitivity, low component count and ease of design. A current-mode equivalent of similar features and possibly better performance is also presented.