UCC38C4x family is a high-performance current- mode PWM controller. It is an enhanced BiCMOS version with pin-for-pin compatibility to the industry standard UC384xA family and UC384x family of PWM controllers. In addition, lower startup voltage versions of 7 V are offered as UCC38C40 and UCC38C41. Providing necessary features to control fixed frequency, peak current-mode power supplies, this family offers the following performance advantages. The device offers high-frequency operation up to 1 MHz with low start-up and operating currents, thus minimizing start-up loss and low operating power consumption for improved efficiency. The device also features a very fast current-mode output limiting function that can limit the output current in each cycle to prevent the output current from exceeding the maximum permissible value.