3544 Power Supply Supervisory Circuit

Category: Electronics, Other Semiconductors, Texas Instruments HighPerformance Analog

Overview

The UC1544/2544/3544 series are monolithic integrated circuits from Texas Instruments designed for the monitoring and control of power supply systems. These devices are integrated with multiple sensing and control functionalities to ensure reliability and performance of power supply units.

Key Features

These supervisory circuits boast a range of features including:

Over-Voltage (O.V.) and Under-Voltage (U.V.) Sensing: Programmable circuits capable of detecting both over and under voltage conditions with optional latch and reset for the O.V. circuit.
Current Sensing: This can be utilized as either a linear amplifier or a high-gain comparator with external compensation.
Internal 1% Accurate Reference: This allows for precise monitoring without external adjustment.
Programmable Time Delays: Timing for fault conditions can be set to ensure accurate triggering of control mechanisms.
SCR “Crowbar” Drive: An integrated circuit capable of delivering 300 mA to trigger an external SCR for power shutdown in O.V. conditions.
Remote Activation: The O.V. sensing circuit can also be remotely activated, enhancing its application versatility.
Uncommitted Comparator Inputs for UC1544 Series: Flexible inputs allow for voltage level monitoring less than 2.5 V by leveraging the internal reference voltage.

Description

The ICs in the UC1544/2544/3544 series contain all necessary components to monitor over-voltage, under-voltage, and current sensing operations. They include undervoltage (U.V.) circuits that can be used to keep tabs on output or input line voltage and a separate op-amp/comparator usable for current sensing or additional voltage monitoring. The reference generator within the circuit is internally trimmed, negating the need for manual calibration. Additionally, the device can be powered directly from the power supply output it is monitoring, or through a separate bias voltage, as required by the specific application.

Block Diagram Description

The block diagram outlines the internal structure and operative connections of the supervisory circuit. Key components include:

U.V. and O.V. sense circuitry, each with their own delay mechanisms and indicators.
Input and ground connections for interfacing with external circuits.
An SCR trigger output connected to the O.V. sense circuit.
Additional output for remote activation of the O.V. circuit.
Uncommitted comparator inputs and offset/compensation provision for additional system flexibility.

An important note emphasizes that specifications are subject to the terms of Texas Instruments’ standard warranty, and production data is current as of the publication date with cautionary advice regarding the use of semiconductor products in critical applications.