This wide range evaluation board showcases the LM3423 NFET controller used with a buck-boost current regulator. It is designed to drive 4 to 8 LEDs at a maximum average LED current of 700 mA from a DC input voltage of 10 to 70V.
The evaluation board showcases most features of the LM3423 including PWM dimming, fault and LED status flags, output overvoltage protection and input under-voltage lockout. It also has a connector footprint (J7) which can mate with an external LED load board allowing for the LEDs to be mounted close to the driver. Alternatively, the LED+ and LED- banana jacks can be used to connect the LED load.
The buck-boost circuit can be easily redesigned for different specifications by changing only a few components (see the Alternate Designs section found at the end of this application note). This board can also be used to evaluate the features and topology of the LM3421 as the LM3423 is a superset of the features and functionality of the LM3421 IC.