The UCC28089 is a versatile BiCMOS controller for dc-to-dc or off-line fixed-frequency switching power supplies. The UCC28089 has dual alternating output stages in dual-alternating push-pull configuration. Both outputs switch at half the oscillator frequency using a toggle flip-flop and duty cycle is limited to less than 50%.
The UCC28089 is optimized for use as the primary-side companion controller for a cascaded converter that has secondary-side control. The device incorporates dead-time programming. The synchronization output also provides dead-time information. The retry and soft-start duration scales with the oscillator clock frequency for high performance fault recovery.
The UCC28089 also provides primary side under-voltage protection (UVLO), and over-current protection. Both the soft start and retry after fault durations scale with oscillator frequency for high performance. The turn-on/off UVLO thresholds are 10.5 V/8.0 V.
Push-Pull Oscillator With Programmable Deadtime
High-Current Totem-Pole Dual Output Stage Drives Push-Pull Configuration with 1-A Sink and 0.5-A Source Capability
Can be Used in Push-Pull, Half-Bridge, or Full-Bridge Topologies
Oscillator Synchronization Output
Low Start-Up Current of 130 µA and 1.4-mA Typical Run Current