This part is a kind of semiconductor called C1251.

Function of this product has UPC1251.

Manufacturers : NEC

Image and pinout :

Some of the text within the PDF file :

DATA SHEET BIPOLAR ANALOG INTEGRATED CIRCUIT μ PC1251GR-9LG, μ PC1251MP-KAA, μ PC358GR-9LG SINGLE POWER SUPPLY DUAL OPERATIONAL AMPLIFIERS www.datasheet4u.com DESCRIPTION The μ PC1251GR-9LG, μ PC1251MP-KAA, μ PC358GR-9LG are dual operational amplifiers which are designed to operate for a single power supply. It includes features of low-voltage operation, a common-mode input voltage that range from V− (GND) level, an output from a V− (GND) level that is determined by the output stage of class C pushpull circuit and a 50 μA(TYP.) constant current, and a low current consumption. In addition, this can operate at both positive and negative power supply and it can be extensively used in various amplifier circuits. The μ PC1251GR-9LG, μ PC1251MP-KAA which expands temperature t [ ... ]

C1251 PDF Datasheet Download