Comparison between differential compensation technics for CMOS two stage amplifier

Operational amplifier is the most essential components in analogue integrated circuit. When designing a two or multistage amplifier, compensation circuit are required. This paper reviews the classic Miller compensation technics for two stage amplifier and compares the performance of various compensation technics includes Nulling resistor, voltage buffer with voltage follower and current buffer method with common gate stage in terms of phase margin, power consumption and bandwidth. According to the theoretical analysis and the simulations results, all the compensation techniques show some advantages compare with the single capacitor miller compensation method (SCMC). All the three compensation technics achieves better stability performance compare with SCMC. Consequently, limited operating range for voltage buffer, more power consumption for current buffer is occurred as a trade-off.