Maxim Integrated Products has introduced what the company claims is the industry's only two-string HB (high-brightness) LED driver for automotive applications.
The MAX16838 integrates a boost or SEPIC switching converter, two linear current sinks, and all necessary power MOSFETs. The device is able to optimize conversion efficiency, provide complete fault protection, and allow a 5000:1 dimming range-without any external components.
The HB LED driver is well suited for LCD backlighting applications, particularly in automotive displays.
The MAX16838 optimizes conversion efficiency by automatically adjusting the switching converter's output voltage to the voltage supply required by the LEDs. A patent-pending architecture allows the device to dim LEDs over a wide 5000:1 range at 200 Hz, while its 200 kHz to 2 MHz switching frequency can be synchronized to an external clock for improved EMC performance. Additionally, the MAX16838 includes a complete set of protections including LED fault, overtemperature, and overvoltage. If an LED fails open or short, the driver automatically disables the affected string while keeping the others working.
Availability and Pricing
Capable of delivering up to 150mA per string, the MAX16838 operates over the -40 to +125 degrees Celsius automotive temperature range and accepts a wide, 4.75V to 40V input range. The device is available in thermally enhanced, 4 mm x 4 mm, 20-pin TQFN and TSSOP packages. Prices start at $1.45 (1000-up, FOB USA).