Texas Instruments

Description

The UC3842A , UC3843A series of high performance fixed frequency current mode controllers are specifically designed for off line and DC to DC converter UC3842A , UC3843A, UC3844A, UC3845A. SLUS224F SEPTEMBER 1994 REVISED OCTOBER 2017. UCx84xA Current-Mode PWM Controller. 1. The UTC UC3842A /3843A provide the necessary functions to implement off-line or DC to DC fixed frequency current mode , controlled switching circuits with utilizing UC3842 control. CURRENT-MODE CONTROL. Figure 1 shows the two- loop current-mode control system in a typical buck regulator application. A. for noise concerns. output ripple: if ripple pollutes feedback, tail chasing can occur. crossover frequency rolloff is mandatory, e.g. in PFC circuits.