UCC3817DG4

Overview

The UCC3817DG4 is a high-performance power factor correction controller manufactured by Texas Instruments. It operates in critical conduction mode (CRM) to optimize efficiency across varying load conditions. The device integrates a precision multiplier, error amplifier, and oscillator to manage input current shaping. Key electrical parameters include an operating supply voltage range of 8.5V to 20V and a maximum switching frequency capability of 100kHz. It features a peak current limit threshold and a soft-start timer for controlled startup sequences. The component is housed in a SOIC-8 surface-mount package.

Feature Summary

• Enables critical conduction mode operation for enhanced power factor correction efficiency
• Integrates a precision analog multiplier for accurate input current sinusoidal shaping
• Includes built-in protection mechanisms such as overvoltage lockout and thermal shutdown

Applications

• Active power factor correction stages in AC-DC power supplies
• High-efficiency desktop computer power adapters
• Charger modules for consumer electronics

Procurement Notes

Verify the specific suffix 'G4' indicates lead-free compliance and RoHS adherence according to Texas Instruments documentation. Confirm the package designation matches the required PCB footprint. Ensure the ordering part number aligns with the exact functional variant intended for the design.

Selection Notes

Select this component when designing systems requiring critical conduction mode PFC controllers. Evaluate the thermal performance requirements for the SOIC-8 package based on the expected power dissipation. Compare the internal oscillator frequency limits against the desired switching speed for EMI filtering considerations.

Part Context

This device belongs to the UCC381x family of power factor correction controllers from Texas Instruments. These components are designed to replace traditional continuous conduction mode solutions, offering improved light-load efficiency. The family focuses on reducing component count and size in offline power conversion applications.

Replacement Considerations

Consult official substitution guides for compatible alternatives within the UCC381x series or equivalent CRM PFC controllers. Verify pin compatibility and control loop stability before replacing existing designs.