BUY A817 https://www.utsource.net/itm/p/195002.html
LOW-DROPOUT 7.7 V PREREGULATOR
Manufacturer: Agilent/FSC Description: NPN Transistor Package/Case: DIP4 Features: Low Collector-Emitter Saturation Voltage High DC Current Gain High Switching Speed High Reliability High Power Dissipation Low Noise Applications: General Purpose Amplifiers Audio Amplifiers High Speed Switching Motor Control Power Management (For reference only)