Low-Power Fully Differential CMOS Filter for Video Frequencies

This brief describes a new low-power fully differential second-order continuous-time low-pass filter for use at video frequencies. The filter uses a single active device in combination with MOSFET resistors and grounded capacitors to achieve very low-power consumption and large dynamic range. The ideal integrator is realized using an internally compensated op-amp consisting of only current mirrors and voltage buffers, while the lossy integrator is implemented by a single passive RC circuit. The filter has been simulated using a CMOS process. Results show that with a single 5-V power supply, cutoff frequency can be tuned from 3.5 to 8 MHz, dynamic range is better than 67 dB and power consumption is less than 1.7 mW.