UC3854A/B Advanced High-Power Factor Preregulator

Category: Electronics, Other Semiconductors, Texas Instruments HighPerformance Analog

Overview

The UC3854A/B from Texas Instruments is an advanced high-power factor preregulator designed for robust power management and improved energy efficiency. It provides nearly ideal power factor correction by controlling a boost pulse-width modulation (PWM) topology. This datasheet, particular to the UC3854A and UC3854B models, provides a comprehensive look at the features, block diagram, and specifications of the devices, aimed to facilitate integration into various power supply and conversion applications.

Key Features

Efficient Power Conversion: The UC3854A/B controls a boost PWM, enhancing line current shaping to achieve near-unity power factor and limiting line current distortion to less than 3%. This makes the device suitable for worldwide operation without requiring any operational switches.

Accurate Regulation and Control: Incorporating fixed-frequency average current-mode control, the UC3854A/B provides stable, low distortion sinusoidal line current. It comes with a high-bandwidth low-offset current amplifier and integrated output clamps for the current- and voltage-amplifiers, enhancing the precision of power delivery.

Improved Functional Range: The UC3854A/B integrates a number of enhancements over its predecessors, including improved linearity, low voltage offset, and an expanded common-mode range (0 V to 5 V) for the multiplier output (MULTOUT).

Comprehensive Monitoring and Safety Features: With a “VREF GOOD” comparator for reference voltage verification, an ENABLE comparator for improved accuracy, Under Voltage Lock Out (UVLO) options, and over-current protection features, the UC3854A/B ensures safe operation across its use-cases.

Low Power and Versatile Start-Up Conditions

The device features a low start-up supply current of 300 µA, minimizing the standby power consumption. UVLO options are provided for different operational thresholds, specifically 16 V/10 V or 10.5 V/10 V, accommodating varying start-up conditions.

Availability and Packaging

The UC3854A/B is available in several packaging options, including 16-pin N (PDIP), DW (SOIC Wide), CDIP, and 20-pin Q (PLCC) packages. The ordering information table (not provided in the excerpt) details the availability for various temperature ranges, ensuring flexibility for different environmental conditions.

General Notice

Critical usage warnings emphasize that information regarding the availability, standard warranty, and functional purpose in critical applications of semiconductor products are subject to standard Texas Instruments’ disclaimers. The datasheet also notifies that the information contained is current as of the publication date and that the products conform to specifications as stipulated by the Texas Instruments standard warranty. Furthermore, production processing may not include testing of all parameters.