UCC2804D/81221G4

Overview

The UCC2804D/81221G4 is a high-performance PWM controller manufactured by Texas Instruments, designed for advanced power conversion applications. It supports Boost, Flyback, and Forward topologies with a maximum switching frequency of 1 MHz. The device operates within a supply voltage range of 8.3V to 12V and features a maximum duty cycle of 50%. It provides a drive output current of 1 A and includes an internal reference voltage of 5.075 V. The component is housed in an SOIC-8 surface-mount package and is rated for operation across a temperature range of -40°C to 85°C.

Feature Summary

• Supports multiple converter topologies including Boost, Flyback, and Forward configurations
• Features a high-speed switching capability up to 1 MHz for compact design
• Includes integrated soft-start functionality to limit inrush current during startup

Applications

• High-density DC-DC converters
• Flyback power supplies
• Forward converter designs

Procurement Notes

Verify the specific suffix '81221' against official Texas Instruments documentation to confirm its exact meaning, as it may denote a specific customer or quality revision rather than a standard commercial variant. Ensure that the G4 suffix indicates lead-free compliance consistent with current manufacturing standards. Cross-reference the datasheet version to ensure all electrical parameters match the intended application requirements before finalizing procurement.

Selection Notes

Select this component when designing isolated or non-isolated converters requiring high-frequency operation and robust control features. The 1 MHz switching frequency allows for smaller passive components compared to lower-frequency alternatives. Consider the SOIC-8 package for space-constrained PCB layouts. Verify that the 50% maximum duty cycle aligns with the specific transformer turns ratio and input-output voltage requirements of the target circuit design.

Part Context

This part belongs to the UCC2804 series of PWM controllers from Texas Instruments, which are widely used in power management solutions. The UCC2804 family is known for its versatility in supporting various power stages. The specific designation UCC2804D/81221G4 indicates a tape-and-reel packaged version with specific manufacturing attributes, distinct from the through-hole DIP variants like the UCC3804N.

Replacement Considerations

The UCC2804DG4 is a direct lead-free equivalent of the UCC2804D series. For pin-compatible replacements, consider the UCC2804DR or UCC2804DTR variants, ensuring the packaging matches the assembly process.