Datasheet UC1846, UC1847, UC2846 UC2847, UC3846, UC3847 (Texas Instruments)
| Hersteller | Texas Instruments |
| Beschreibung | UCx846/7 Current Mode PWM Controller |
| Seiten / Seite | 24 / 1 — UC1846,. UC1847. , UC2846. UC2847,. UC3846. , UC3847. UCx846/7 Current … |
| Dateiformat / Größe | PDF / 1.3 Mb |
| Dokumentensprache | Englisch |
UC1846,. UC1847. , UC2846. UC2847,. UC3846. , UC3847. UCx846/7 Current Mode PWM Controller. 1 Features. 3 Description. 2 Applications
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UC1846, UC1847 , UC2846 UC2847, UC3846 , UC3847
SLUS352C – JANUARY 1997 – REVISED DECEMBER 2015
UCx846/7 Current Mode PWM Controller 1 Features 3 Description
The UC1846/7 family of control devices provides all • Automatic Feedforward Compensation 1 of the necessary features to implement fixed- • Programmable Pulse-by-Pulse Current Limiting frequency, current-mode control schemes while • Automatic Symmetry Correction in Push-Pull maintaining a minimum external parts count. The Configuration superior performance of this technique can be measured in improved line regulation, enhanced load • Enhanced Load Response Characteristics response characteristics, and a simpler, easier-to- • Parallel Operation Capability for Modular Power design control loop. Topological advantages include Systems inherent pulse-by-pulse current limiting capability, • Differential Current Sense Amplifier with Wide automatic symmetry correction for push-pull Common Mode Range converters, and the ability to parallel power modules while maintaining equal current sharing. • Double-Pulse Suppression • 500-mA (Peak) Totem-pole Outputs Protection circuitry includes built-in undervoltage lockout and programmable current limit, in addition to • ±1% Band Gap Reference soft-start capability. A shutdown function is also • Undervoltage Lockout available, which can initiate either a complete • Soft-Start Capability shutdown with automatic restart or latch the supply off. • Shutdown Terminal • 500-kHz Operation Other features include fully-latched operation, double- pulse suppression, deadline adjust capability, and a
2 Applications
±1% trimmed band gap reference. • Telecommunication Power Converters The UC1846 features low outputs in the OFF state, while the UCx847 features high outputs in the OFF • Industrial Power Converters state.
Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM)
LCCC (20) 8.89 mm × 8.89 mm UC1846 CDIP (16) 6.92 mm × 19.56 mm PLCC (20) 8.96 mm × 8.96 mm UC2846, UC3846 SOIC (16) 7.5 mm × 10.3 mm PDIP (16) 6.35 mm × 19.3 mm SOIC (16) 7.5 mm × 10.3 mm UC2847, UC3847 PDIP (16) 6.35 mm × 19.3 mm (1) For all available packages, see the orderable addendum at the end of the datasheet.
Block Diagram
VIN 15 180Ÿ .1µF V 2W IN 2 13 VREF VC .05µF .5k 1N42 4 4 2 5 4 9 11 RT AOUT 2N4150 UES1402 200µH .005µF 68Ÿ 8 1k VO CT 4 C/S+ UCX846 3.2k 5 68Ÿ 1k +E/A B 14 300µF OUT 100µF 2N4150 1N4245 UES1402 3.2k 6 -E/A 3 .5Q C/S- .05µF 7 COMP CS/SS 1 VREF 68k .0015 SH-DN GND 1.5k 16 12 1k 3.6k 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. 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
UC1846, UC1847 , UC2846 UC2847, UC3846 , UC3847
SLUS352C – JANUARY 1997 – REVISED DECEMBER 2015
UCx846/7 Current Mode PWM Controller 1 Features 3 Description
The UC1846/7 family of control devices provides all • Automatic Feedforward Compensation 1 of the necessary features to implement fixed- • Programmable Pulse-by-Pulse Current Limiting frequency, current-mode control schemes while • Automatic Symmetry Correction in Push-Pull maintaining a minimum external parts count. The Configuration superior performance of this technique can be measured in improved line regulation, enhanced load • Enhanced Load Response Characteristics response characteristics, and a simpler, easier-to- • Parallel Operation Capability for Modular Power design control loop. Topological advantages include Systems inherent pulse-by-pulse current limiting capability, • Differential Current Sense Amplifier with Wide automatic symmetry correction for push-pull Common Mode Range converters, and the ability to parallel power modules while maintaining equal current sharing. • Double-Pulse Suppression • 500-mA (Peak) Totem-pole Outputs Protection circuitry includes built-in undervoltage lockout and programmable current limit, in addition to • ±1% Band Gap Reference soft-start capability. A shutdown function is also • Undervoltage Lockout available, which can initiate either a complete • Soft-Start Capability shutdown with automatic restart or latch the supply off. • Shutdown Terminal • 500-kHz Operation Other features include fully-latched operation, double- pulse suppression, deadline adjust capability, and a
2 Applications
±1% trimmed band gap reference. • Telecommunication Power Converters The UC1846 features low outputs in the OFF state, while the UCx847 features high outputs in the OFF • Industrial Power Converters state.
Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM)
LCCC (20) 8.89 mm × 8.89 mm UC1846 CDIP (16) 6.92 mm × 19.56 mm PLCC (20) 8.96 mm × 8.96 mm UC2846, UC3846 SOIC (16) 7.5 mm × 10.3 mm PDIP (16) 6.35 mm × 19.3 mm SOIC (16) 7.5 mm × 10.3 mm UC2847, UC3847 PDIP (16) 6.35 mm × 19.3 mm (1) For all available packages, see the orderable addendum at the end of the datasheet.
Block Diagram
VIN 15 180Ÿ .1µF V 2W IN 2 13 VREF VC .05µF .5k 1N42 4 4 2 5 4 9 11 RT AOUT 2N4150 UES1402 200µH .005µF 68Ÿ 8 1k VO CT 4 C/S+ UCX846 3.2k 5 68Ÿ 1k +E/A B 14 300µF OUT 100µF 2N4150 1N4245 UES1402 3.2k 6 -E/A 3 .5Q C/S- .05µF 7 COMP CS/SS 1 VREF 68k .0015 SH-DN GND 1.5k 16 12 1k 3.6k 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. 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