The APA2057A is a monolithic integrated circuit, which combines a stereo power amplifier and a stereo output capacitor-less headphone amplifier. The stereo power amplifier provides 19-steps gain setting for flexible application. The headphone amplifier is ground-reference output, and no need the output capacitors for DC blocking. The advantages of eliminating the output capacitor are saving the cost, PCB’s space and component height. Both the de-pop circuitry and the thermal shutdown protection circuitry are integrated in the APA2057A, which reduces pops and clicks noise during power on/ off and in shutdown mode. Thermal shutdown protects the chip from being destroyed by over-temperature failure. To simplify the audio system design in notebook computer applications, the APA2057A provides the internal gain setting, and these features can minimize components and PCB area. The APA2057A is available in both TSSOP-28P and TQFN5x5-28 packages. Both packages are characterized by space saving and thermal efficiency.