The UCC35701/UCC35702 family of pulse width modulators is intended for isolated switching power supplies using primary side control. They can be used for both off-line applications and DC/DC converter designs such as in a distributed power system architecture or as a telecom power source.
The devices feature low startup current, allowing for efficient off-line starting, yet have sufficient output drive to switch power MOSFETs in excess of 500kHz.
Voltage feed forward compensation is operational over a 5:1 input range and provides fast and accurate response to input voltage changes over a 4:1 range. An accurate volt-second clamp and maximum duty cycle limit are also featured.
Fault protection is provided by pulse by pulse current limiting as well as the ability to latch off after a programmable number of repetitive faults has occurred.
Two UVLO options are offered. UCC35701 family has turn-on and turn-off thresholds of 13V/9V and UCC35702 family has thresholds of 9.6V/8.8V.
The UCC35701/2 and the UCC25701/2 are offered in the 14 pin SOIC (D), 14 pin PDIP (N) or in 14 pin TSSOP (PW) packages. The UCC15701/2 is offered in the 14 pin CDIP (J) package.
| Topology | Boost, Flyback, Forward |
| Control mode | Feedforward, Voltage |
| Duty cycle (max) (%) | 99 |
| Switching frequency (max) (kHz) | 700 |
| Features | Adjustable switching frequency, Current limiting, Multi-topology, Programmable max duty cycle, Soft start, Synchronization pin |
| UVLO thresholds on/off (V) | 9.6/8.8 |
| Operating temperature range (°C) | -40 to 85 |
| Rating | Catalog |
| Gate drive (typ) (A) | 1 |
| Vin (max) (V) | 15 |
| PDIP (N) | 14 | 181.42 mm² 19.3 x 9.4 |
| SOIC (D) | 14 | 51.9 mm² 8.65 x 6 |
| TSSOP (PW) | 14 | 32 mm² 5 x 6.4 |