This part is a kind of semiconductor called A8178LLR.
Function of this product has LOW-DROPOUT/ 7.7 V PREREGULATOR.
Manufacturers : Allegro MicroSystems
Image and pinout :
Some of the text within the PDF file :
8178 PRODUCT PREVIEW (Subject to change without notice) April 5, 1996 Data Sheet 27468.22 LOW-DROPOUT, 7.7 V PREREGULATOR Designed specifically to meet the stringent requirements of automotive applications, the A8178LLR and A8178LLT provide an output voltage of 7.7 V ±15% for supply voltages greater than 6.9 V. They also provide a low-dropout tracking output for supply voltages down to 2.5 V. These regulators are intended to be used with sensitive automotive electronics systems that do not have the capability of low dropout operation and cannot withstand the high-voltage transients typical of automotive applications. These 7.7 V preregulators will withstand all ISO pulses (ignition coil disconnect requires an external diode) and will continue to operate during positive power supply tran [ ... ]