DESCRIPTION
The LT®1246/LT1247 are 8-pin, fixed frequency, current mode, pulse width modulators. These devices are de signed 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.
FEATURES
â Current Mode Operation to 1MHz
â 30ns Current Sense Delay
â < 250µA Low Start-Up Current
â Current Sense Leading Edge Blanking
â Pin Compatible with UC1842
â Undervoltage Lockout with Hysteresis
â No Cross-Conduction Current
â Trimmed Bandgap Reference
â 1A Totem Pole Output
â Trimmed Oscillator Frequency and Sink Current
â Active Pull-Down on Reference and Output During Undervoltage Lockout
â 18V High Level Output Clamp
APPLICATIONS
â Off-Line Converters
â DC/DC Converters
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