The UCC35705 and UCC35706 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.
The UCC25705 is an 8‑pin voltage‑mode primary‑side controller featuring a high‑speed oscillator with integrated feed‑forward compensation, fast over‑current protection, and a programmable maximum duty‑cycle clamp. It is offered in MSOP‑8, SOIC‑8, and PDIP‑8 packages and is suited for high‑performance isolated and non‑isolated power converters.
The document provides absolute maximum ratings, electrical characteristics, pin descriptions, functional description, mechanical dimensions, and regulatory notices. It also lists available UVLO options and ordering information for taped‑and‑reeled devices.
| Output current (OUT) | up to 20 mA |
|---|---|
| Storage temperature | -65 °C to 150 °C |
The propagation delay from PWM to OUT is typically 65 ns to 120 ns.
The UVLO start‑threshold for the UCC25705 is typically 8.8 V (range 8.0 V to 9.6 V).