1 MHz current-mode PWM controller for isolated offline supplies
The UCC3808AD-1 is a current-mode PWM controller from Texas Instruments designed for isolated offline power supplies. It supports multiple topologies including Boost, Buck, Half-Bridge, and Push-Pull, making it a flexible choice for a range of DC-DC converter architectures. Switching at up to 1 MHz allows the use of smaller magnetics, shrinking the overall power supply footprint. The 49% maximum duty cycle suits half-bridge and push-pull stages where balanced flux reset is critical. The 8.3 V to 15 V supply range gives headroom for startup and hold-up in regulated offline rails.
Package and board-fit note
The 8-SOIC footprint is standard for low-pin-count PWM controllers and mates with common SOIC-8 land patterns. The control features include Frequency Control, allowing the oscillator timing to be set with external R-C components. Output isolation is built into the control architecture, enabling galvanically isolated designs with an external transformer and optocoupler feedback.
Lifecycle and compliance
Compliant with ROHS3 — no restricted substances above the exemption thresholds. This simplifies compliance for products destined for EU or other RoHS-regulated markets.