LM3409EVAL: 1A @ 15V MAx, 6 ~ 42V in


This demonstration board showcases the LM3409 PFET controller for a buck current regulator. It is designed to drive 4 LEDs (VO = 15V) at a maximum average LED current (ILED = 1A) from a DC input voltage (VIN = 24V). The switching frequency (fSW = 525 kHz) is targeted for the nominal operating point, however fSW varies across the entire operating range. The circuit can accept an input voltage of 6V-42V. However, if the input voltage drops below the regulated LED string voltage, the converter goes into dropout and VO = VIN ideally.

The demonstration board showcases several features of the LM3409 including both analog dimming using a potentiometer (R5) tied to the IADJ pin and internal PWM dimming using the EN pin. There is a header (J1) with a removable jumper, which is used to select PWM dimming or low power shutdown. The board has a right angle connector (J2) which can mate with an external LED load board allowing for the LEDs to be mounted close to the driver. This reduces potential ringing when there is no output capacitor. Alternatively, the LED+ and LED- turrets can be used to connect the LED load.


Manufacturer Texas Instruments
Category Lighting
Sub-Category LED Drivers - DC In
Eval Board Part Number LM3409EVAL/NOPB-ND
Eval Board Supplier Texas Instruments
Eval Board Normally In Stock
Voltage In 6 ~ 42 V (24 V)
Topology Step Down
Current Out 1 A
Voltage Out (Max) 15 V
Outputs and Type 1 Non-Isolated
Efficiency @ Conditions >94%, 24V in, 4 LEDs(15V) @ 1 A
Features Dimming Control
Shutdown, Enable, Standby
Switching Frequency 525 kHz
Component Count + Extras 13 + 7
Design Author Texas Instruments
Application / Target Market
Main I.C. Base Part LM3409
Date Created By Author 2009-11
Date Added To Library 2012-10

Share This Design

Eval Board

Order a fully assembled board:

Quantity Available: 5