LM3409EVAL

The LM3409EVAL evaluation 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 = 525kHz) is targeted for the nominal operating point, however Fsw varies across the entire operating range. However, if the input voltage drops below the regulated LED string voltage, the converter goes into dropout and VO = VIN ideally. The evaluation 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.

• 6V to 42V input voltage range
• Differential, high side current sense
• Cycle by cycle current limit
• No control loop compensation required
• 10,000:1 PWM dimming range
• 250:1 analog dimming range
• Supports all ceramic output capacitors and capacitor less outputs
• Low power shutdown and thermal shutdown

Applications

Automotive, LED Lighting, Industrial, Power Management