Low-Voltage And Low-Power Current-Feedback Operational Amplifiers Applied For Audio/Video Chip On The Mp4

The purpose of low power design is to minimize the energy consumption of an embedded system and extend the lifetime of battery without losing its performance. With the developing requirement in size and performance of embedded devices from the market, the gap between small size, high performance and the limited battery life has become more and more wide, low power design of embedded system is an efficient approach to solve that problem. This paper firstly aims at the low power MP4 in the whole;then the low-voltage and low-power current-feedback operational amplifiers applied for audio /video chip is designed for MP4.The paper describes the MP4 overall low power design. The purpose of low power design of hardware is to give a hardware support to optimize the energy consumption of whole system. Low power design of hardware at circuit level focuses on low power character of processor and peripherals, designs the power supply circuit of processor and peripherals, the peripherals' power supply circuit allows processor to control peripherals' power supply, from these we can restrict energy consumption of the peripherals. The design circuit after the debugging can operate normally, satisfy the MP4 low power request, the product has put into the market.MP4 audio /video chip processes wide bandwidth of audio /video signal, but in the chip the voltage pattern amplifier bandwidth is limited by the gain, therefore the research on the wideband current feedback operational amplifier has the practical significance. Current-feedback operational amplifiers is widely used in the high speed and frequency electronic fields,but complementary-bipolar process CFOA is popular in the market for high voltage and high power. To the design of analog circuit, it is a challenge when its supply voltage is low.Now the typical supply voltage of analog circuit is about 2.5-3 v, but the trend suggests it will be 1.5v, even much lower .Under this condition, great effort of research members domestic and abroad is devoted to the design of low-voltage circuit structure with standard CMOS processes.The aim of this paper is to describe a new CMOS current-feedback operational amplifiers . Compared with the model CMOS current feedback operational amplifier, this paper enhances the open-loop gain in the among level with the reverse amplifier, capacitor compensates the phase margin safeguarding thecircuit the stability. The typical CMOS current feedback operational amplifier output stage is class AB complementary emitter output unit, but the high output impedance affects the circuit dynamic performance, this paper using the resistance feedback reduces the output impedance to enhance the circuit the dynamic performance. Simulation results of the CFOA,using 0.5um CMOS process parameters, result in a high slewrate as well as bandwidth gain-independence . Circuit parameters show a: 81db open loop gain-. 82 degree phase margin> 123db CMRR ■> and power consumption around 6.2mW from 1.5V supply voltage.