The MAX16814 high-efficiency, high-brightness LED (HB LED) driver provides up to four integrated LED current-sink channels. An integrated current-mode switching DC-DC controller drives a DC-DC converter that provides the necessary voltage to multiple strings of HB LEDs. The MAX16814 accepts a wide 4.75V to 40V input voltage range and withstands direct automotive load-dump events. The wide input range allows powering HB LEDs for small to medium-sized LCD displays in automotive and general lighting applications.
An internal current-mode switching DC-DC controller supports the boost, coupled-inductor buck-boost, or SEPIC topologies and operates in an adjustable frequency range between 200kHz and 2MHz. It can also be used for single-inductor buck-boost topology in conjunction with the MAX15054 and an additional MOSFET. The current-mode control with programmable slope compensation provides fast response and simplifies loop compensation. The MAX16814 also features an adaptive output-voltage control scheme that minimizes the power dissipation in the LED current-sink paths.
The MAX16814 consists of four identical linear current source channels to drive four strings of HB LEDs. The channel current is adjustable from 20mA to 150mA with an accuracy of ±3% using an external resistor. The external resistor sets all 4-channel currents to the same value. The device allows connecting multiple channels in parallel to achieve higher current per LED string. The MAX16814 also features pulsed dimming control, with very short minimum pulse width as low as 1µs, on all four channels through a logic input (DIM).
The MAX16814 includes an output overvoltage, open-LED detection and protection, programmable shorted LED detection and protection, and overtemperature protection. The device operates over the -40°C to +125°C automotive temperature range. The MAX16814 is available in the 6.5mm x 4.4mm, 20-pin TSSOP and 4mm x 4mm, 20-pin TQFN packages.
Key Features
Applications/Uses
4-Channel Linear LED Current Sinks with Internal MOSFETs
Full-Scale LED Current Adjustable from 20mA to 150mA
Drives One to Four LED Strings
Boost, SEPIC, or Coupled-Inductor Buck-Boost Current-Mode DC-DC Controller
200kHz to 2MHz Programmable Switching Frequency
External Switching Frequency Synchronization
Adaptive Output-Voltage Optimization to Minimize Power Dissipation
4.75V to 40V Operating Input Voltage Range
Less than 40µA Shutdown Current
5000:1 PWM Dimming at 200Hz
Open-Drain Fault Indicator Output
Open-LED and LED Short Detection and Protection
Overtemperature Protection
Thermally Enhanced, 20-Pin TQFN and TSSOP Packages
Architectural, Industrial, and Ambient Lighting
Automotive Displays LED Backlights
Automotive RCL, DRL, Front Position, and Fog Lights
