LT1247

PRODUCTION

1MHz Off-Line Current Mode PWM and DC/DC Converter

Part Models: 3
1ku List Price: Starting From $2.59

Viewing:

Overview

Current Mode Operation to 1MHz
30ns Current Sense Delay
<250µA Low Start-Up Current
Current Sense Leading Edge Blanking
Pin Compatible with UC1842
Undervoltage Lockout with Hysteresis
No Cross-Conduction Current
Trimmed Bandgap Reference
1A Totem Pole Output

The LT1246/LT1247 are 8-pin, fixed frequency, current mode, pulse width modulators. These devices are designed to be improved plug compatible versions of the industry standard UC1842 PWM circuit. The LT1246/LT1247 are optimized for off-line and DC/DC converter applications. They contain a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output stage ideally suited to driving power MOSFETs. Start-up current has been reduced to less than 250µA. Cross-conduction current spikes in the totem pole output stage have been eliminated, making 1MHz operation practical. Several new features have been incorporated. Leading edge blanking has been added to the current sense comparator. This minimizes or eliminates the filter that is normally required. Eliminating this filter allows the current sense loop to operate with minimum delays. Trims have been added to the oscillator circuit for both frequency and sink current, and both of these parameters are tightly specified. The output stage is clamped to a maximum V_OUT of 18V in the on state. The output and the reference output are actively pulled low during under-voltage lockout.

Applications

Off-Line Converters
DC/DC Converters

Part Models: 3
1ku List Price: Starting From $2.59

Documentation

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LT1247CN8#PBF	8-Lead PDIP (Narrow 0.3 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT1247CS8#PBF	8-Lead SOIC (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT1247CS8#TRPBF	8-Lead SOIC (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Oct 8, 2024 - 24_0234 Migrating Bottom Trace Code Marking to Top Side Laser Marking for PDIP Package
		PCN24_0234_Form Material_Report Marking Comparison
LT1247CN8#PBF	PRODUCTION	PCN24_0234_Form Material_Report Marking Comparison
Oct 11, 2022 - 22_0241 Epoxy Change from Henkel 8290 to 8290A for PDIP Package
		PCN22_0241_Form Material_Report Qualification Results Summary
LT1247CN8#PBF	PRODUCTION
Aug 6, 2022 - 22_0172 Laser Top Mark Conversion for PDIP Packages Assembled in ADPG [PNG]
		PCN22_0172_Form Material_Report Delta Qualification Matrix
LT1247CN8#PBF	PRODUCTION
Dec 14, 2023 - 22_0255 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 2 of 2)
		PCN22_0255_Form Material_Report Qualification Results Summary Delta Qualification Matrix
LT1247CS8#PBF	PRODUCTION
LT1247CS8#TRPBF	PRODUCTION
Jun 11, 2021 - 21_0060 Laser Top Mark for 8SOICN Assembled in ADPG, UTL and CRM
		PCN21_0060_Form Material_Report Delta Qualification Matrix
LT1247CS8#PBF	PRODUCTION
LT1247CS8#TRPBF	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Software Resources

Can't find the software or driver you need?

Request a Driver/Software

Tools & Simulations

LTspice

Models for the following parts are available in LTspice:

LT1247

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.