MAXIM Integrated Products, represented by Arrow Electronics Australia Pty Ltd , has introduced high-brightness (HB) LED drivers with a wide input-voltage range, the MAX16801/MAX16802.
The MAX16801 is suitable for universal ac input (rectified 85V to 265Vac) LED drivers, while the MAX16802 is intended for dc-input-voltage LED drivers (10.8V to 24VDC or higher with external bias).
The MAX16801/MAX16802 have a 262kHz fixed switching frequency and current-mode control.
An external MOSFET provides high-power (over 50W) and high-efficiency (over 85%) operation and allows for small size components which reduces system cost.
Strings of HB LEDs can be driven with a wide (0 to 100%) dimming range by using PWM or linear dimming control.
When the LED current requires tight regulation, designers can use the additional on-board error amplifier with a 1% accurate reference.
These devices are ideal for buck, boost, SEPIC and isolated or nonisolated flyback topologies in general lighting applications, decorative and architectural lighting, display backlighting and other constant current-source LED applications.
Both devices feature an ultra-low 45μA startup current, allowing the use of high-value startup resistors and low-value startup capacitors. LED driver startup is fast, while dissipation is substantially reduced.
An input voltage undervoltage lockout (UVLO) allows setting of the input start voltage with an external resistor-divider. Pulling the UVLO pin low shuts down the devices.
The MAX16801/MAX16802 include digital soft-start, which results in superior control of the output current rise during startup. This eliminates virtually all output current overshoots.
Both devices include thermal shutdown and are available with a 50% or 75% maximum duty cycle.
Rated for operation over the extended temperature range (-40°C to +85°C), the MAX16801/MAX16802 are available in a surface-mount, lead-free, 8-pin microMAX package.