The LM3404MRX/NOPB from Texas Instruments is a 1A constant current buck regulator for driving high power LEDs in 8 pin SO PowerPAD package. This monolithic switching regulator is designed to deliver constant currents to high power LEDs. This device contains a high side N-channel MOSFET switch with a current limit of 1.5A (typical) for step-down (buck) regulators. The LM3404HV device is a buck regulator with a wide input voltage range, low voltage reference and a fast output enable and disable function. Hysteretic controlled on-time and an external resistor allow the converter output voltage to adjust as needed to deliver a constant current to series and series-parallel connected LED arrays of varying number and type. Some features are: LED dimming using pulse width modulation (PWM), broken or open LED protection, low-power shutdown and thermal shutdown.
VIN range from 6V to 42V
1.2A output current overtemperature
Cycle by cycle current limit, thermal shutdown protection
No control loop compensation required
Separate PWM dimming and low power shutdown
Supports all ceramic output capacitors and capacitor-less outputs
IIN operating current is 625µA (non-switching, CS=0.5V), IIN shutdown current is 95µA (RON / SD=0V)
