LT1243
PRODUCTIONHigh Speed Current Mode Pulse Width Modulators
- Part Models
- 6
- 1ku List Price
- Starting From $3.30
Overview
- Low Start-Up Current: <250µA
- 50ns Current Sense Delay
- Current Mode Operation: To 500kHz
- Pin Compatible with UC1842 Series
- Undervoltage Lockout with Hysteresis
- No Cross-Conduction Current
- Trimmed Bandgap Reference
- 1A Totem Pole Output
- Trimmed Oscillator Frequency and Sink Current
- Active Pull-Down on Reference and Output During Undervoltage Lockout
- High Level Output Clamp: 18V
- Current Sense Leading Edge Blanking
The LT1241 series devices are 8-pin, fixed frequency, current mode, pulse width modulators. They are improved plug compatible versions of the industry standard UC1842 series. These devices have both improved speed and lower quiescent current. The LT1241 series is 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 output stage have been eliminated, making 500kHz operation practical. Several new features have been incorporated. Leading edge blanking has been added to the current sense comparator. 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 VOUT of 18V in the on state. The output and the reference output are actively pulled low during undervoltage lockout.
Applications
- Off-Line Converters
- DC/DC Converters
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 |
|---|---|---|---|
| LT1243CN8#PBF | 8-Lead PDIP (Narrow 0.3 Inch) | ||
| LT1243CS8#PBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1243CS8#TRPBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1243IN8#PBF | 8-Lead PDIP (Narrow 0.3 Inch) | ||
| LT1243IS8#PBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1243IS8#TRPBF | 8-Lead SOIC (Narrow 0.15 Inch) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Oct 8, 2024 - 24_0234 Migrating Bottom Trace Code Marking to Top Side Laser Marking for PDIP Package |
||
| LT1243CN8#PBF | PRODUCTION | |
| LT1243IN8#PBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0241 Epoxy Change from Henkel 8290 to 8290A for PDIP Package |
||
| LT1243CN8#PBF | PRODUCTION | |
| LT1243IN8#PBF | PRODUCTION | |
|
Aug 6, 2022 - 22_0172 Laser Top Mark Conversion for PDIP Packages Assembled in ADPG [PNG] |
||
| LT1243CN8#PBF | PRODUCTION | |
| LT1243IN8#PBF | PRODUCTION | |
|
Dec 14, 2023 - 22_0255 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 2 of 2) |
||
| LT1243CS8#PBF | PRODUCTION | |
| LT1243CS8#TRPBF | PRODUCTION | |
| LT1243IS8#PBF | PRODUCTION | |
| LT1243IS8#TRPBF | PRODUCTION | |
|
Jun 11, 2021 - 21_0060 Laser Top Mark for 8SOICN Assembled in ADPG, UTL and CRM |
||
| LT1243CS8#PBF | PRODUCTION | |
| LT1243CS8#TRPBF | PRODUCTION | |
| LT1243IS8#PBF | PRODUCTION | |
| LT1243IS8#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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LTspice 1
Models for the following parts are available in LTspice:
- LT1243
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.