Micropower two-stage amplifier employing recycling current-buffer Miller compensation

Proposed is a two-stage amplifier exploiting recycling current-buffer Miller compensation (CBMC). By reusing the most current-consuming devices in the 1
^st
stage as current buffer, such an amplifier not only can preserve the merits of typical CBMC implementation in creating the beneficial left-half-plane (LHP) zero, but also can avoid the drawbacks of typical CBMC scheme from degrading the power efficiency, DC gain, dc offset and noise performances. Optimized in 0.18μm CMOS via a low-power design procedure, the amplifier achieves >90dB DC gain, 4.5MHz unity-gain frequency and 57.2° phase margin at a 100pF capacitive load. The average slew rate and 1% settling time are 2.68V/μs and 0.239μs, respectively. The amplifier draws 22μA at a 1.2V supply.