The LM3421/23 are versatile high voltage N-channel MosFET controllers for LED drivers . They can be easily configured in buck, boost, buck-boost and SEPIC topologies. This flexibility, along with an input voltage rating of 75V, makes the LM3421/23 ideal for illuminating LEDs in a large family of applications.
Adjustable high-side current sense voltage allows for tight regulation of the LED current with the highest efficiency possible. The LM3421/23 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 LM3421/23 devices include 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 2.0 MHz, thus enabling compact solutions. Additional features include "zero current" shutdown, analog dimming, PWM dimming, over-voltage protection, under-voltage lock-out, cycle-by-cycle current limit, and thermal shutdown.
The LM3423 also includes an LED output status flag, a fault flag, a programmable fault timer, and a logic input to select the polarity of the dimming output driver.
The LM3421Q1/23Q1 are AEC-Q100 grade 1 qualified and LM3421Q0/23Q0 are AEC-Q100 grade 0 qualified.
LM3421Q1/LM3423Q1 are Automotive Grade Products That are AEC-Q100 Grade 1 Qualified (-40°C to +125°C Operating Junction Temperature) and Similarly LM3421Q0/LM3423Q0 are AEC-Q100 Grade 0 Qualified (-40°C to +150°C Operating Junction Temperature)
VIN Range From 4.5V to 75V
High-Side Adjustable Current Sense
2Ω, 1A Peak MosFET Gate Driver
Input Under-Voltage and Output Over-Voltage Protection
PWM and Analog Dimming
Cycle-by-Cycle Current Limit
Programmable Switching Frequency
"Zero Current" Shutdown and Thermal Shutdown
LED Output Status Flag (LM3423/23Q1/23Q0 Only)
Fault Status Flag and Timer (LM3423/23Q1/23Q0 Only)