Research On Low - Voltage And Low - Power Operational Amplifier Based On Constant - Current Diode

With the popularization of tablet, mobile phones, and other various mobile electronic devices, the batteries are widely used as the power of microelectronics products. An urgent need on battery as a power source of electronic products is to adopt low current low voltage analog circuits to reduce power consumption. JEFT combined with bipolar devices, has become one of the main development directions of integrated operational amplifier. With this background, this thesis studies on general integrated op-amp design from another innovative thought, that is to put forward the operational amplifier based on current rectifying diode(CRD).In this thesis, a JEFT is designed to constitute a current rectifying diode(CRD),the first step in research is to study its constant current characteristics, such as the constant current value of the current rectifying diode, open voltage, breakdown voltage, temperature characteristic are studied, respectively. Then the compatibility of current rectifying diode with bipolar transistor processing is studied. Finally, the bipolar junction transistors, which used as constant current source and active load, is replaced by current rectifying diode. Meanwhile, the circuit structure is optimized in order to reduce number of devices, so that to reduce the chip area and lower the power dissipation to realize low power consumption in further. The simulation results show that with the variation of power supply, the input current varies between 0.290 mA and0.433 mA in bipolar operational amplifier; while the input current would reduce about a half for an operational amplifier based on current rectifying diode, the input current keeps between 0.239 m A and 0.244 mA, the total change of current is of only 0.005 mA.When the power supply is kept at 13 V, the bias current of bipolar operational amplifier reach 0.739 mA, which is about 3 times larger 0.222 mA that used in operational amplifier based current rectifying diode. The simulation results can draw a conclusion that the operational amplifier based on current rectifying diode can realize even lower static current and power consumption.