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LED driver integrates analog, PWM dimming control

Sunnyvale, Calif. — Maxim Integrated Products has introduced the MAX16812 high-voltage, switch-mode, high-brightness (HB) LED driver with analog and PWM-dimming control. To minimize component count and cost, this device integrates a high-side/differential LED current-sense amplifier and a PWM-dimming MOSFET driver.

The MAX16812 also integrates a 76-V rated, 0.2-ohm switching MOSFET and provides a 100 kHz to 500 kHz operating frequency range. The highly integrated MAX16812 is suitable for compact HB LED driver applications that require a wide 100:1 dimming-control range such as interior and exterior automotive, as well as emergency, architectural, and other lighting applications.

The use of an internal dimming MOSFET driver enhances system reliability by automatically switching off power to the LED strings during automotive load-dump events, said Maxim. The MAX16812 also provides ±5% accurate LED-current control for enhanced reliability and brightness matching. An on-board, 200-Hz ramp generator allows PWM-dimming control with an external analog signal, or it can be synchronized to an external PWM signal.

Linearly controlled PWM dimming is said to simplify implementation of two-level brightness control and theater dimming. During PWM dimming, the MAX16812 controls the LED current rise and fall times to suppress electromagnetic interference (EMI) and system noise. To further reduce EMI, an external resistor can be connected between the gate driver and internal switching MOSFET for control of the switching current rise and fall times, said Maxim.

Designed to withstand harsh operating environments, the MAX16812 operates from a 5.5-V to 76-V supply-voltage range for cold-start and load-dump compliance. This HB LED driver also features over-voltage protection, under-voltage lockout, soft-start, and thermal shutdown. The MAX16812 is fully specified over the -40° to +125°C automotive temperature range, and is available in a thermally enhanced, 5 x 5-mm, 28-pin TQFN package.

Pricing: Starts at $2.10 (1000-up, FOB USA).
Datasheet: MAX16812

Maxim Integrated Products , 1-800-998-8800, www.maxim-ic.com

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