The UCC35701/UCC35702 pulse width modulator series is suitable for isolated switching power supplies using main side control. Available in 14-pin SOIC (D), 14-pin PDIP (N) or 14-pin TSSOP (PW) packages. UCC15701/2 comes in 14-pin CDIP (J) package. They can be used either in off-line applications or in DC/DC converter designs, such as distributed power system architectures or telecommunications power supplies.
Typical application diagram
The device has a low starting current that allows efficient off-line starting, but has enough output drivers to switch mosFets with power over 500kHz. Voltage feedforward compensation operates in the 5:1 input range and provides a fast and accurate response to input voltage changes in the 4:1 range. Precise volt-second clamping and maximum duty cycle limits are also featured.
Failure protection is provided by pulse-to-pulse current limitation and the ability to latch after a programmable number of repeated failures occur. Two UVLO options are available. The switch threshold of the UCC35701 series is 13V/9V, and that of the UCC35702 series is 9.6V/8.8V.
Detailed block diagram
