UC2543, UC3543 Power Supply Supervisory Circuit

Category: Electronics, Other Semiconductors, Texas Instruments HighPerformance Analog

Overview

The Texas Instruments UC1544/2544/3544 series integrated circuits are sophisticated supervisory components designed for power supply systems. The main features include over-voltage (O.V.), under-voltage (U.V.), and current sensing circuits, along with an accurate reference generator and various programmability options.

Key Features

The core functionalities incorporate:

Over-voltage sensing with options to trigger an external SCR “crowbar” shutdown.
Under-voltage monitoring with programmable delays.
Current sensing usable as a linear amplifier or high-gain comparator.
All circuits feature open-collector outputs that can be used individually or combined.
An internally accurate reference to within 1%, eliminating the need for external adjustments.
Remote activation capability for flexible control.
An optional over-voltage latch for persistent fault indication.

The device allows for external programming of fault duration before triggering and offers uncommitted comparator inputs for low voltage sensing—an exclusive feature to the UC1544 series.

Description

The Texas Instruments datasheet describes the UC1544/2544/3544 family as monolithic integrated circuits that centralize the control and monitoring of power supply outputs. These chips are ideal for managing over-voltage and under-voltage conditions and offer considerable versatility. For example, the UC1544 model includes additional customizable inputs for monitoring levels as low as 2.5V. The inclusion of an SCR “crowbar” feature provides a means to shut down power supplies quickly in response to over-voltage events.

Block Diagram Explanation

The block diagram included on the datasheet illustrates the operational segments of the ICs:

U.V. Sense and Delay show the arrangement for under-voltage detection and the delay before signaling an error condition.
O.V. Sense and Delay components highlight the features for over-voltage fault detection with adjustable response timing.
The Reference Generator, labeled as VREF, is centralized and provides precise voltage for comparator references and other uses.
An SCR Trigger circuit is directly related to the O.V. Sense block, capable of activating the SCR “crowbar.”
Uncommitted comparator inputs (inv) and offset/compensation elements are shown, granting flexibility for various types of voltage sensing.

General Information

The datasheet concludes with notices concerning the availability, standard warranty, and usage in critical applications of Texas Instruments semiconductor products. It emphasizes that all the production data is current as of the publication date and that the products conform to specifications per the terms of the Texas Instruments standard warranty. Moreover, it clarifies that the production process may not include testing of all parameters.