The LM3409, LM3409-Q1, LM3409HV, and
LM3409HV-Q1 are P-channel MOSFET (PFET)
controllers for step-down (buck) current regulators.
They offer wide input voltage range, high-side
differential current sense with low adjustable
threshold voltage and fast output enable/disable
function and a thermally enhanced 10-pin, HVSSOP
package. These features combine to make the
LM3409 family of devices ideal for use as constant
current sources for driving LEDs where forward
currents up to 5 A are easily achievable.
The LM3409 devices use constant off-time (COFT)
control to regulate an accurate constant current
without the need for external control loop
compensation. Analog and PWM dimming are easy to
implement and result in a highly linear dimming range
with excellent achievable contrast ratios.
Programmable UVLO, low-power shutdown, and
thermal shutdown complete the feature set