Design of Temperature-insensitive and High Gain Operational Amplifier

The power amplifier is a high-power device,which can consume most of the power,and change the temperature of the chip in a large extent,therefore,the output power control circuit of PA should be insensitive to the change of ambient temperature.A temperature-insensitive and fully differential CMOS operational amplifier is designed based on TSMC 0.18μm process,and it consists of folding cascode opamp and wide-swing bias circuit.The maximum DC gain up to 115dBm and the phase margin is 70 degrees under the conditions that load capacitance is 10p;the gain variation is only 1dBm and the phase margin is only 5 degrees in the entire temperature range(-40~125 ℃).