Maxim Integrated Products introduces the MAX16807-MAX16810 family of multichannel, constant-current, linear LED drivers with an integrated switch-mode voltage controller. These devices are fully integrated, high-brightness LED drivers that address industry needs for mercury-free, high-contrast lighting in displays. These drivers also provide the accurate and matched constant-current control in multiple LED strings required for automotive and other premium LCD displays, such as in notebook and desktop monitors, LCD TVs and industrial LCD panels.
Produced with an environmentally friendly, lead-free technology, these LED drivers also are packaged in the industry's smallest footprint. The MAX16807-MAX16810 feature a current-mode PWM controller. These LED drivers provide 8 or 16 open-drain, constant-current sinking, parallelable outputs, which are resistor-programmable up to 55mA per channel and rated for 36V continuous operation. The PWM controller delivers up to 1A of load current at the maximum 40V output voltage and high efficiency (up to 92% overall efficiency) using an external MOSFET. The MAX16807/MAX16808 operate either in stand-alone mode or with a microcontroller using a 25Mbps, industry-standard (shift-register-plus-latch-type), 4-wire serial interface. A dedicated dimming input provides fast turn-off and turn-on of all LED channels, thus enabling dimming ratios up to 5000:1.
The drivers feature a wide adjustable frequency range (25kHz to 1MHz) that allows design optimization based on trade-offs in efficiency, space (by using miniature inductor and capacitors), and EMI minimization. The MAX16807-MAX16810 combine individual constant-current control of each channel with an accurate bandgap reference for the proper accuracy and channel-to-channel matching. By using the integrated switch-mode controller for boost or in a single-ended, primary-inductance converter (SEPIC) buck-boost topology, the wide input-voltage range can be regulated up to 36V continuous (40V absolute maximum) LED voltage. The device input can be directly biased from 8V to 26.5V and higher with a simple external biasing device. LED technology development is fast-paced and challenges LED driving electronics. It is imperative that LED drivers provide accurate and matched constant-current control over multiple LED strings. Driver control must operate from a wide-range input supply, optimized for an application, and must span a wide temperature range.
These devices operate over the -40°C to +125°C temperature range and are available in a thermally enhanced, 28-pin, exposed pad TSSOP package (MAX16807, MAX16808) and 38-pin, 7mm x 5mm TQFN package (MAX16809, MAX16810). The pricing starts at $2.71 for MAX16809/10 and $2.04 for MAX16807/08 (1000-up, FOB USA).
