The UC1842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC3842/3/4/5 family....
Switching Controller, Current-mode, 1A, 500kHz Switching Freq-Max, BIPolar, PDIP8,
Switching Controller, Current-mode, 1A, 500kHz Switching Freq-Max, BIPolar, PDSO14,