A 100-MHz 100-dB operational amplifier with multipath nested Miller compensation structure

A 100-MHz bipolar operational amplifier has a gain of 100 dB. The op amp owes its high unity-gain bandwidth and high gain to an all-n-p-n signal path and multipath nested Miller compensation (MNMC). The phase margin with a 100-pF load is 40 degrees at 100 MHz and the amplifier settles in 60 ns to 0.1% on a 1-V step. For comparison, a similar op amp without the multipath technique has been realized. The unity-gain bandwidth of this nested Miller compensation (NMC) op amp is 60 MHz and the settling time is 70 ns. Theory and measurements confirm that the multipath technique almost doubles the bandwidth of nested Miller compensated amplifiers.>