Optimized for industrial and automotive LED applications, this new family provides constant current through LEDs and features low feedback voltage to minimize power dissipation.
National’s LM3402, LM3404 and LM3405 light-emitting diode (LED) drivers are designed to power the new generation of 1W to 5W, high-brightness LEDs found in automotive, industrial and general illumination applications.
These products offer the wider input voltage range required by this fast-growing market segment. In addition, National’s new LED drivers provide a constant current to regulate the LED brightness and low feedback voltage to minimize power dissipation.
Optimized for 1W LEDs, National Semiconductor offers two versions of the LM3402 LED driver that provide wide input voltage ranges of either 6V to 42V or 6V to 75V. For 3W and 5W LEDs, the LM3404 and LM3405 have additional output current drive capability.
Technical Features of the LED Drivers
The LM3402 is a compact, constant-current buck regulator with up to 95 percent efficiency that drives up to 525 mA of current. Offered in an 8-pin mini SOIC package, the LM3402 has an enable pin that also can be used for dimming via pulse-width modulation (PWM) inputs and a reduced feedback of 0.2V for current sensing. The LM3402‘s input voltage ranges from 6V to 42V. For higher input voltages, the LM3402HV offers the same features and a 6V-to-75V voltage range.
Offered in an 8-pin SOIC narrow package, the LM3404 and LM3404HV share the same functionality as the LM3402 and LM3402HV, but have the ability to drive currents up to 1.2A. These products are well-suited to power 3W and 5W LEDs at current levels of 700 mA or 1A respectively.
Offered in an 8-pin mini SOIC package, the LM3405 constant-current buck regulator delivers up to 1A of current to drive 3W or 5W LEDs. With a 0.2V reference voltage for constant-current feedback control and a switching frequency that is internally set to either 550 kHz or 1.6 MHz, the LM3405 provides a simple, highly-efficient solution for driving LEDs. In addition, the LM3405 has an input voltage range of 3V to 22V, is internally compensated and has an En/Dim pin for PWM dimming.
Features & benefits :
LM3402
- Integrated 0.5A N-channel MOSFET
- VIN range from 6V to 42V (LM3402)
- VIN range from 6V to 75V (LM3402HV)
- 500 mA output current over temperature
- Cycle-by-cycle current limit
- No control loop compensation required
- Separate PWM dimming and low power shutdown
- Supports all-ceramic output capacitors and capacitor-less output
- Thermal shutdown protection
- MSOP-8, PSOP-8 packages
LM3404
- Integrated 1.0A MOSFET
- VIN range 6V to 42V (LM3404)
- VIN range 6V to 75V (LM3404HV)
- 1.2A Output current over temperature
- Cycle-by-cycle current limit
- No control loop compensation required
- Separate PWM dimming and low power shutdown
- Supports all-ceramic output capacitors and capacitor-less outputs
- Thermal shutdown protection
- SO-8 package, PSOP-8 package
LM3405
- VIN operating range of 3V to 15V
- Thin SOT23-6 package
- 1.6MHz switching frequency
- 300mΩ NMOS switch
- 40nA shutdown current at VIN = 5V
- EN/DIM input for enabling and PWM dimming of LEDs
- Internally compensated current-mode control
- Cycle-by-cycle current limit
- Input voltage UVLO
- Over-current protection
- Thermal shutdown
Application information:
- LED driver
- Constant current source
- Automotive lighting
- General illumination
- Industrial lighting
- LED flashlights
Product information table:
| Mftrs. Part No. | Product Description |