The MAX16812 is a peak-current-mode LED driver with an integrated 0.2Ω power MOSFET designed to control the current in a single string of high-brightness LEDs (HB LEDs). The MAX16812 can be used in multiple converter topologies such as buck, boost, or buck-boost. The MAX16812 operates over a 5.5V to 76V wide supply voltage range.

The MAX16812 features a low-frequency, wide-range brightness adjustment (100:1), analog and PWM dimming control input, as well as a resistor-programmable EMI suppression circuitry to control the rise and fall times of the internal switching MOSFET. A high-side LED current-sense amplifier and a dimming MOSFET driver are also included, simplifying the design and reducing the total component count.

The MAX16812 uses peak-current-mode control, adjustable slope compensation that allows for additional design flexibility. The device has two current regulation loops. The first loop controls the internal switching MOSFET peak current, while the second current regulation loop controls the LED current. Switching frequency can be adjusted from 125kHz to 500kHz.

Additional features include adjustable UVLO, soft-start, external enable/disable input, thermal shutdown, a 1.238V 1% accurate buffered reference, and an on-chip oscillator. An internal 5.2V linear regulator supplies up to 20mA to power external devices.

The MAX16812 is available in a thermally enhanced 5mm x 5mm, 28-pin TQFN-EP package and is specified over the automotive -40°C to +125°C temperature range.

MAX16812: Simplified Diagram

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Key Features

Integrated 76V, 0.2Ω (typ) Power MOSFET
5.5V to 76V Wide Input Range
Adjustable LED Current with 5% Accuracy
Floating Differential LED Current-Sense Amplifier
Floating Dimming N-Channel MOSFET Driver
PWM LED Dimming with:
- PWM Control Signal
- Analog Control Signal
- Chopped V_IN Input
Peak-Current-Mode Control
125kHz to 500kHz Adjustable Switching Frequency
Adjustable UVLO and Soft-Start
Output Overvoltage Protection
5µs LED Current Rise/Fall Times During Dimming Minimize EMI
Overtemperature and Short-Circuit Protection