The LT1243CS8#PBF is a high speed current-mode Pulse Width Modulator, an improved plug compatible versions of the industry standard UC1842 series. It has both improved speed and lower quiescent current. The LT1241 series is optimized for off-line and DC/DC converter applications. It contains 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.
<250μA Low start-up current
50ns Current sense delay
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
(EN)
