Datasheet UC1846, UC1847, UC2846 UC2847, UC3846, UC3847 (Texas Instruments) - 4

UC1846, UC1847 , UC2846 UC2847, UC3846 , UC3847
SLUS352C – JANUARY 1997 – REVISED DECEMBER 2015
www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Supply Voltage (Pin 15) 40 V Collector Supply Voltage (Pin 13) 40 V Output Current, Source or Sink (Pins 11, 14) 500 mA Analog Inputs (Pins 3, 4, 5, 6, 16) –0.3 +VIN V Reference Output Current (Pin 2) –30 mA Sync Output Current (Pin 10) –5 mA Error Amplifier Output Current (Pin 7) –5 mA Soft Start Sink Current (Pin 1) 50 mA Oscillator Charging Current (Pin 9) 5 mA Power Dissipation at TA = 25°C 1000 mW Power Dissipation at TC = 25°C 2000 mW Storage temperature, Tstg –65 150 °C (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
6.2 ESD Ratings VALUE UNIT
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2500 V(ESD) Electrostatic discharge V Charged-device model (CDM), per JEDEC specification JESD22- ±1500 C101(2) (1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. (2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
VREF terminal external capacitance 1 2.2 µF
6.4 Thermal Information UCx846/7 N or DW (PDIP or J or DW (CDIP or THERMAL METRIC(1) UNIT SOIC) SOIC) 16 PINS 16 PINS
RθJA Junction-to-ambient thermal resistance 41.8 73.1 °C/W RθJC(top) Junction-to-case (top) thermal resistance 28.5 34.2 °C/W RθJB Junction-to-board thermal resistance 21.8 38.0 °C/W ψJT Junction-to-top characterization parameter 13.0 7.7 °C/W ψJB Junction-to-board characterization parameter 21.7 37.4 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance N/A N/A °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. 4 Submit Documentation Feedback Copyright © 1997–2015, Texas Instruments Incorporated Product Folder Links: UC1846 UC1847 UC2846 UC2847 UC3846 UC3847 Document Outline 1 Features 2 Applications 3 Description Table of Contents 4 Revision History 5 Pin Configuration and Functions 6 Specifications 6.1 Absolute Maximum Ratings 6.2 ESD Ratings 6.3 Recommended Operating Conditions 6.4 Thermal Information 6.5 Electrical Characteristics 6.6 Typical Characteristics 7 Detailed Description 7.1 Overview 7.2 Functional Block Diagram 7.3 Feature Description 7.3.1 Current Sense Amplifier 7.3.2 Oscillator 7.4 Device Functional Modes 7.4.1 Current Limit 7.4.2 Shutdown 8 Application and Implementation 8.1 Application Information 8.2 Typical Application 8.2.1 Design Requirements 8.2.2 Detailed Design Procedure 8.2.2.1 Design Switching Frequency 8.2.2.2 Error Amplifier Output Configuration 8.2.2.3 Parallel Operation Configuration 8.2.2.4 Design Pulse by Pulse Current Limit Threshold 8.2.2.5 Soft-Start and Shutdown, Restart Function Design 8.2.3 Application Curves 9 Power Supply Recommendations 10 Layout 10.1 Layout Guidelines 10.2 Layout Example 11 Device and Documentation Support 11.1 Related Links 11.2 Community Resources 11.3 Trademarks 11.4 Electrostatic Discharge Caution 11.5 Glossary 12 Mechanical, Packaging, and Orderable Information