BUY STA481A https://www.utsource.net/itm/p/976670.html
NPN Darlington Transistors With built-in avalanche diodeNPN）
Description: The STA481A is a monolithic integrated circuit designed for use in the output stage of audio amplifiers. Features: High output power: up to 25W into 4Ω Low distortion: 0.02% THD+N Low quiescent current: 0.3A Low external component count Thermal protection Short-circuit protection Over-voltage protection Under-voltage protection Over-temperature protection Over-current protection Soft start Low EMI Low noise High efficiency Low ESR output capacitor Low external component count Low external component cost High reliability Applications: Home audio systems Car audio systems Portable audio systems Professional audio systems Active speakers Soundbars Karaoke systems (For reference only)