This part is a kind of semiconductor called TC59.

Function of this product has Low Dropout / Negative Output Voltage Regulator Designed Specifically.

Manufacturers : Microchip Technology

Image and pinout :

Some of the text within the PDF file :

TC59 Low Dropout, Negative Output Voltage Regulator Features • Low Dropout Voltage - Typically 120mV @ 50mA; 380mV @ 100mA for -5.0V Output Part • Tight Output Voltage Tolerance: ±2% Max • Low Supply Current: 3.5µA, Typ • Small Package: 3-Pin SOT-23A General Description The TC59 is a low dropout, negative output voltage regulator designed specifically for battery-operated systems. Its full CMOS construction eliminates the wasted ground current typical of bipolar LDOs. This reduced supply current significantly extends battery life, particularly when the TC59 is operated in dropout. Other TC59 key features include low supply current (typically 3.0µA) and low dropout operation (typically 120mV at 50mA). The TC59 is packaged in a small 3-Pin SOT-23A package. Applications • • [ ... ]

TC59 PDF Datasheet Download