The Research And Design Of CMOS Low Power Operational Amplifier

In recent years, more and more electronic products with battery supply are widely used, which cries for adopting low voltage analog circuits to reduce power consumption, therefore low voltage, low power analog circuit design techniques are becoming research hotspot, and considered from the energy, the low power dissipation not only is the portable equipment demand which the battery supply, is the large-scale system urgent need.The operational amplifier took in the integrated circuit the most basic unit, its importance is well known. In low voltage operational amplifier, because supply voltage reducing, the signal dynamirange reduces, at the same time, the noise signal scope increases relatively, the amplifier signal to noise ratio reduces. In order to expand the signal the dynamirange, the low voltage operational amplifier usually needs the input signal scope and the output signal scope to be able to achieve the entire amplitude, in view of this question, this article discusses as follows: one is designed with AB rail-to-rail output stage. Usually the low power operational amplifier is designed with rail to rail output stage, whose signal dynamirange is small, its output driving force is not strong, here it is designed with voltage displacement stage, and the strong driving force and the low power consumption in this circuit are achieved. With 5V single power, this amplifier consumes only severalμA, 100KHz unity-gain frequency, achieves 80dB dc open gain and 55°phase margin for a 100pF load capacitance and a 1MΩload resistance and other advantages. The other is the design of amplifier with constant trans-conductance (gm) rail-to-rail input stage. When common mode input voltage changes, it provides nearly constant-gm independent of input transistor operating region (strong, moderate or weak inversion), and the quiet nods of the circuit for current addition and the output stage keep unchanged. These chips based on this design may be used for mobile communication, personal digital assistant, portable audios etc.In this thesis, developing situation and characteristic and basic application of operational amplifiers are introduced in chapter l. The electric characteristic of MOSFETS is analyzed in detail in chapter 2. In chapter 3, the configuration of an operational amplifier is confirmed in base of the characteristic parameter, which is needed firstly, and the probable value of configuration parameter in this circuit is calculated artificially. The operational amplifier that is designed in chapter 3 is simulated...