This part is a kind of semiconductor called UC3843A.

Function of this product has (UC3842A - UC3845A) HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

UC284XA UC384XA HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER NOT FOR NEW DESIGN 1 FEATURES Figure 1. Package ■ TRIMMED OSCILLATOR DISCHARGE CURRENT ■ CURRENT MODE OPERATION TO 500kHz AUTOMATIC FEED FORWARD COMPENSATION DIP-8 SO-8 ■ LATCHING PWM FOR CYCLE-BY-CYCLE CURRENT LIMITING Table 1. Order Codes ■ INTERNALLY TRIMMED REFERENCE WITH Part Number Package UNDERVOLTAGE LOCKOUT ■ HIGH CURRENT TOTEM POLE OUTPUT t(s)UNDERVOLTAGE LOCKOUT WITH HYSTERESIS c■ LOW START-UP CURRENT (< 0.5mA) uDOUBLE PULSE SUPPRESSION rod2 DESCRIPTION PThe UC384xA family of control ICs provides the necessary features to implement off-line or DC to teDC fixed frequency current mode control schemes lewith a minimal external parts count. Internally imoplemented circuits include a trimmed osci [ ... ]

UC3843A PDF Datasheet Download