Greater Than 4-MHz Operation

Integrated Oscillator / Voltage Feed Forward

Compensation

>4:1 Input Voltage Range

25-ns Current Limit Delay

Programmable Maximum Duty Cycle Clamp

Optocoupler Interface

50-μA Start-Up Current

4.2-mA Operating Current @ 1 MHz

Smallest Footprint of the 8-pin MSOP

Package Minimizes Board Area and Height

description

The UCC35705 and UCC35706 devices are 8-pin voltage mode primary side controllers with fast over-current

protection. These devices are used as core high-speed building blocks in high performance isolated and non-isolated

power converters.

UCC35705/UCC35706 devices feature a high speed oscillator with integrated feed-forward compensation for

improved converter performance. A typical current sense to output delay time of 25 ns provides fast response to

overload conditions. The IC also provides an accurate programmable maximum duty cycle clamp for increased

protection which can also be disabled for the oscillator to run at maximum possible duty cycle.

Two UVLO options are offered. The UCC35705 with lower turn-on voltage is intended for dc-to-dc converters while

the higher turn-on voltage and the wider UVLO range of the UCC35706 is better suited for offline applications.

The UCC35705/UCC35706 family is offered in 8-pin MSOP (DGK), SOIC (D) and PDIP (P) packages.