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UCC28C45DR

TIUCC28C45DR

Texas Instruments
Boost, Flyback, Forward Converter Regulator Positive Output Step-Up, Step-Up/Step-Down DC-DC Controller IC 8-SOIC
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Overview

The UCC28C45DR is a high-performance, BiCMOS current-mode PWM controller designed for efficient DC-DC conversion. It supports Boost, Flyback, and Forward topologies with a maximum duty cycle of 48 percent and features a high-speed 35ns current-limit-to-output delay. This device is a pin-to-pin compatible, lower-power upgrade for the industry-standard UC284x family.

Why Choose This Part

It offers significantly lower startup and operating currents (2.3mA at 52kHz) compared to older bipolar versions, extending efficiency in low-load conditions. The controller provides a precise 2.5V reference with 1 percent accuracy and includes robust undervoltage lockout (UVLO) protections to ensure safe power-up sequences.

Applications

Isolated Flyback Converters
Used in AC-DC or DC-DC power supplies providing galvanic isolation for industrial equipment.
Boost Converters
Efficiently stepping up lower bus voltages to higher levels for driving loads or intermediate rails.
Forward Converters
Utilized in high-density power modules where duty cycles under 50 percent are required for transformer reset.
Switch-Mode Power Supplies (SMPS)
General purpose power conversion in systems requiring a regulated 7.6V to 18V supply range.

Key Specifications

Function Step-Up, Step-Up/Step-Down
Topology Boost, Flyback, Forward Converter
Clock Sync No
Output Type Transistor Driver
Mounting Type Surface Mount
Output Phases 1
Package / Case 8-SOIC (0.154", 3.90mm Width)
Control Features Frequency Control
Duty Cycle (Max) 48%
Number of Outputs 1
Output Configuration Positive
Frequency - Switching Up to 1MHz
Operating Temperature -40degC ~ 105degC (TJ)
Synchronous Rectifier No
Supplier Device Package 8-SOIC
Voltage - Supply (Vcc/Vdd) 7.6V ~ 18V

Getting Started

To evaluate this controller, engineers typically use a prototype PCB with a SOIC-8 footprint or the UCC28C45EVM evaluation module. Design involves selecting an external MOSFET driven by the 1A peak rail-to-rail output and tuning the oscillator frequency using an external RC network.

Also Consider

UCC28C43DR TITexas Instruments - An alternative in the same BiCMOS family that allows for duty cycles up to 100 percent instead of the 48 percent limit.
LT1243 Analog Devices - A high-speed pin-compatible alternative that offers faster internal comparators for improved transient response.