2-Stage HiFi Headphone Amplifier Schematic

This was the final project for our Integrated Circuit Design and Analysis class. We needed to build a 2 stage amplifier that met the following specifications: 1) Maximum output power (continuous): >100 mW/ch (on battery) 2) Output impedance: <5ohms 3) Input impedance: >10kohms 4) 3-dB full-power bandwidth: 20Hz-15kHz (min), 18Hz-20kHz (max) 5) Total harmonic distortion + noise (THD+N): <0.2% with 100mW on nominal load at 1kHz 6) Power consumption: <100mA (on battery) or <200mA (on regulated AC power) at max output power For extra credit, we designed our second stage of the amplifier using BJTs in a push pull configuration.