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
■ 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
■ Trimmed Oscillator Frequency and Sink Current
■ Active Pull-Down on Reference and Output During Undervoltage Lockout
■ 18V High Level Output Clamp

APPLICATIONS
■ Off-Line Converters
■ DC/DC Converters