LM3429 PowerWise® N-Channel Controller

N-Channel Controller for Constant Current LED Drivers - Now Available at Digi-Key

National Semiconductor LM3429 PowerWise® N-Channel ControllerNational Semiconductor's LM3429 is a versatile high voltage N-channel MOSFET controller for LED drivers. It can be easily configured in buck, boost, buck-boost and SEPIC topologies. This flexibility, along with an input voltage rating of 75V, makes the LM3429 ideal for illuminating LEDs in a very diverse, large family of applications.

Adjustable high-side current sense voltage allows for tight regulation of the LED current with the highest efficiency possible. The LM3429 uses Predictive Off-time (PRO) control, which is a combination of peak current-mode control and a predictive off-timer. This method of control eases the design of loop compensation while providing inherent input voltage feed-forward compensation.

The LM3429 includes a high-voltage startup regulator that operates over a wide input range of 4.5V to 75V. The internal PWM controller is designed for adjustable switching frequencies of up to 2.0MHz, thus enabling compact solutions. Additional features include analog dimming, PWM dimming, over-voltage protection, under-voltage lock-out, cycle-by-cycle current limit, and thermal shutdown.
The LM3429 comes in a low profile, thermally-efficient TSSOP EP 14-lead package.      LM3429 Datasheet

  • Features & Applications
  • Diagram
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  • VIN range from 4.5V to 75V
  • Adjustable current sense voltage
  • High-side current sensing
  • 2Ω, 1A peak MOSFET gate driver
  • Input under-voltage protection
  • Over-voltage protection
  • PWM dimming
  • Analog dimming
  • Cycle-by-cycle current limit
  • Programmable switching frequency
  • Thermal shutdown
  • TSSOP EP 14-lead package

  • LED drivers
  • Constant-current buck-boost (or flyback) regulator
  • Constant-current boost regulator
  • Constant-current buck regulator
  • Constant-current SEPIC regulator
  • Thermo-electric cooler (Peltier) driver

  • RoHS Compliant

Typical Application Circuit Diagram

National Semiconductor LM3429 PowerWise® N-Channel Controller

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Part Number
National Semiconductor
Part Number
Current Output /
Package / Case
Switched Inductor,
Step-Up (Boost),
Step-Down (Buck)
14-TSSOP Exposed Pad, 14-eTSSOP 14-HTSSOP

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