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CM3842/3843
CURRENT MODE PWM CONTROLLER
GENERAL DESCRIPTION
FEATURES
The CM3842/43 are fixed frequency current-mode PWM !
controllers specially designed for OFF-Line switching !
power supply and DC-to-DC converters with a minimum !
number of external components. These devices feature !
a trimmed oscillator for precise duty cycle control, a !
temperature compensated reference, high gain error !
amplifier, current sensing comparator, and high current !
totem pole output which is suitable for driving !
MOSFETs.
!
The under voltage lock-out (U.V.L.O.) is designed to
operated with 200µA typ. start-up current, allowing an
efficient bootstrap supply voltage design. The U.V.L.O.
thresholds for the CM3842 are 16V (on) and 10V (off)
which are ideal for off-line applications.