The Design Of CMOS If Filter

Filter is used as a signal processing a basic components, almost to apply to all the electron, the electric power system, filter performance quality directly determine the quality of the products. Along with the development of modern electronic technology, the traditional passive filter in volume, weight, power consumption and filtering effect so as emerged gradually disadvantage, in order to satisfy the multi-function, high precision, stable and reliable requirements, the1970s appeared active filter, digital filters, switch capacitance filter, and other types of filters, later, new filter is used for integrated circuits, continuously improve product performance, reduce the cost of product, and make product application more simple.This paper designed a low-power, cutoff frequency adjustable for1MHz or500KHz active low-pass filter, the transmission characteristics into four grades for the Sallen Butterworth, circuit and Key specific structure, in order to reduce power consumption, circuit design a little bandwidth low power amp. The op-amp in two level, and conventional two-stage op-amp by different, its first pole, so after low level provide electrical flow of45°can achieve the phase power margin, to reduce power consumption purposes.Design uses0.5muon m CMOS technology, complete the circuit design, layout design. Cadence simulation results show that, the static power consumption to meet the design for1.035mW index requirements.