The AL5817 is an 8-terminal adjustable linear LED driver-controller offering excellent temperature stability and output current capability. It works with a wide input voltage range from 4.5V to 60V. With an external LED driving power device, its internal power dissipation is minimized compared with traditional linear LED drivers. This makes it ideal for medium to high current LED circuits.
The AL5817 has internal output drive capability up to 15mA, which enables it to drive external Bipolar transistors or MOSFETs. It also provides the capability to drive longer LED chains with low drop out voltage and multiple LED channels.
The VSET pin is used to directly set output current feedback level. Using a resistor divider between REF pin and VSET pin, the output current can be set. Additionally, the use of an NTC resistor allows the creation of an accurate and configurable thermal fold-back behavior.
The AL5817 provides an LED-open detection feature through its VFAULT pin. If VFAULT is brought lower than 2.5V (by any one of the multiple LED channels going open) the AL5817’s output will go low turning off the external transistors. The device will recover when the open condition is removed. This ability of VFAULT to turn off the external transistors also allows PWM dimming of the LED current by adding PWM control signal on VFAULT pin.
An enable pin ENB is available to externally turn on and off the LEDs.
The AL5817 is available in the thermally enhanced MSOP-8EP package.
Automotive Rear Combination Light
Wide Input Voltage Range from 4.5V to 60V
Configurable LED Current Setting
4% Reference Voltage Tolerance
Low Temperature Drift
15mA Output Drive Capability for MOSFET or Bipolar Transistor
LED Open Protection Detected by VFAULT Pin
LED Thermal Fold-back Configured by VSET
Overtemperature Protection (OTP)
Input Under Voltage Lock-Out
PWM Dimming Realized Through VFAULT Pin or ENB Pin