Maxim introduces the MAX16831 high-voltage, high-power, constant-current LED driver with built-in analog and PWM dimming. The LED driver integrates a floating LED current sense amplifier with a dimming MOSFET driver to minimize component count and meet the high reliability requirements of automotive and general lighting applications with high brightness (HB) LEDs. Operating over a 5.4V to 76V input voltage range, the MAX16831 withstands harsh operating conditions, ensuring compatibility with cold-start and load rejection (up to 80V). The device is specifically optimized to meet the latest automotive headlamp design requirements, ideal for high beam and low beam, adaptively adjusted headlight systems, daytime running lights and fog lights.
The MAX16831 operates at high frequencies with a wide (1000:1) dimming range and built-in analog and PWM control. The analog control signal simplifies the design of multi-level brightness adjustment compared to the on-chip 200Hz ramp signal. The LED driver provides ±5% LED current control accuracy over the entire automotive operating temperature range, ensuring excellent brightness matching. An LED current sense reference as low as 100mV and an internal gate driver with 1.4A/1.2A source/sink current capability enable high efficiency to minimize device heat generation. A dedicated enable/shutdown input reduces the current in shutdown mode to less than 45μA.
The MAX16831 features output overvoltage and overcurrent protection, as well as overtemperature and LED short-circuit protection. The device operates over the automotive temperature range of -40°C to +125°C and is available in a lead-free, 5mm x 5mm, 32-pin TQFN package with an exposed pad. The chip starts at $2.33 (1000 sheets, FOB USA).
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September 18, 2018