UC3849QTR

Power Supply Controllers, Monitors Overview

The UC3849QTR is a secondary-side average current mode PWM controller manufactured by Texas Instruments. It operates within a frequency range up to 1000 kHz and supports a maximum switching frequency of 500 kHz. The device features a 28-pin PLCC package with dimensions of 11.51x11.51 mm. It functions within an operating temperature range of 0°C to +70°C. The controller provides dual outputs and includes integrated protection features such as undervoltage lockout, cycle-by-cycle current limiting, and soft-start capability for stable power supply regulation.

Power Supply Controllers, Monitors Feature Summary

• Implements secondary-side average current mode control for precise regulation
• Supports high-frequency operation up to 1 MHz for compact magnetics
• Integrates comprehensive protection mechanisms including UVLO and current limiting

Power Supply Controllers, Monitors Applications

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

Power Supply Controllers, Monitors Procurement Notes

Verify the specific suffix QTR indicates tape and reel packaging configuration when ordering. Confirm the 28-PLCC package variant matches your PCB footprint requirements. Ensure the commercial temperature grade (0°C to +70°C) aligns with your system environmental specifications. Cross-reference the manufacturer part number with official Texas Instruments documentation to avoid counterfeit components.

Power Supply Controllers, Monitors Selection Notes

Select this component for applications requiring secondary-side sensing to improve load regulation accuracy. Consider the 28-pin PLCC package for surface-mount assembly compatibility. Evaluate the 500 kHz to 1 MHz frequency range against transformer size constraints. Verify that the commercial temperature range meets operational needs without additional cooling measures.

Power Supply Controllers, Monitors Part Context

The UC3849 belongs to the UC series of PWM controllers designed for isolated power conversion. It complements primary-side controllers by providing accurate secondary feedback. The QTR suffix typically denotes reel packaging for automated assembly. This component fits within the broader portfolio of Texas Instruments power management solutions for industrial and consumer electronics.

Power Supply Controllers, Monitors Replacement Considerations

Check for direct pin-compatible alternatives in the UC384x family. Verify functional equivalence regarding current mode control architecture. Ensure package dimensions and thermal characteristics match existing designs.