Current Mirror Based Filter

Analog baseband circuits, including filters and programmable gain amplifiers (PGA), are indispensable in wireless sensors and communication systems. Portable devices continue to drive the need for circuits that achieve low power without sacrificing linearity. These analog baseband filters typically consume tens of mW and have a considerable impact on the total power consumption of a transceiver. Wireless receivers today demand low-noise and linear baseband channel select filters to accommodate the large dynamic range of the input signals. Power dissipation and die area of these filters must also be as small as possible. Analog frond ends are usually integrated with digital function blocks in recent mixed-signal Soc applications including data communication and image processing systems. Low power and small area ADCs with 8–10b accuracy operating several tens of MS/s are considered important building blocks. However each ADC has to he preceded by a front end anti-alias filter with cut off frequency in MHz range. There are two major concerns when we design a wideband LPF. One is the selection of filter LCR prototype, that is, Butterworth, Chebychev, Bessel etc. The other is the selection between G_m-C and active-RC.