Compensation-Based Optimization Methodology for Gain-Boosted OPAMP

摘要

A gain-boosted OPAMP design methodology is presented. The methodology provides a systematic way of gain-boosted OPAMP optimization in terms of AC response and settling performance. The evolution of the major poles and zeros of the gain-boosted OPAMP is studied, which reveals the rationale behind our optimization effort. A sample OPAMP was implemented in 0.6 micrometere CMOS technology. It achieves a DC gain of 88 decibels, a bandwidth of 725MHz with 490 phase margin and a 0.1 settling time of 4.5ns. The sample/hold front-end of a 12-bit 5OMSample/s ADC was implemented with this OPAMP. It achieves an SNR of 78 decibels for an 8.1MHz input signal.