AL5817MP-13 Diodes Incorporated

AL5817 60V LINEAR DIMMABLE LED CONTROLLER Description Pin Assignments The AL5817 is an 8-terminal adjustable linear LED driver-controller (Top View) 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 VCC 1 8 VFAULT minimized compared with traditional linear LED drivers. This makes it ideal for medium to high current LED circuits. 2 ENB REF 7 The AL5817 has internal output drive capability up to 15mA, which EP enables it to drive external Bipolar transistors or MOSFETs. It also 3 6 VSET OUT provides the capability to drive longer LED chains with low drop out voltage and multiple LED channels. 4 GND 5 FB 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. MSOP-8EP 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 AL5817s output will go low Applications turning off the external transistors. The device will recover when the open condition is removed. This ability of VFAULT to turn off the Automotive Rear Combination Light external transistors also allows PWM dimming of the LED current by LED Signs adding PWM control signal on VFAULT pin. Instrumentation Illumination An enable pin ENB is available to externally turn on and off the LEDs. Refrigerator Lights The AL5817 is available in the thermally enhanced MSOP-8EP package. Features 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 Over Temperature Protection (OTP) Input Under Voltage Lock-Out PWM Dimming Realized Through VFAULT Pin or ENB Pin Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See AL5817 Typical Application Circuit V IN V IN AL5817 D1 AL5817 D1 VCC VFAULT VCC VFAULT REF ENB R3 R3 REF ENB Q1 R2 Q1 R2 R4 VSET OUT R4 VSET OUT C1 C1 GND FB GND FB R1 R5 R1 R5 Figure 1 Pin Descriptions Pin Number Pin Name Function 1 VCC Supply input Internal reference voltage. The maximum recommended output current is 50A and the maximum recommended capacitor 2 REF connected from this pin to GND is less than 100pF. A potential divider from REF to VSET can be used to accurately set the output LED current. LED current setting threshold. The voltage on VSET sets the reference voltage for the FB pin. This pin is pulled down internally if left 3 VSET floating. The capacitance if needed between VSET and GND is recommended to be less than 1nF. Ground 4 GND Feedback input. When control loop is operating in linear mode the FB pin will be regulated to the level set by VSET. This pin is pulled up internally if left floating. 5 FB A capacitor may be added between FB and GND to improve noise rejection. Value needs to be limited 100pF or less. 6 OUT Driving output Chip Enable 7 ENB An input voltage >2V disables the device and external transistor drive. This pin can be used for low frequency PWM dimming of the LED current. Input for LED-open detection. When LED-open detection function is active, if VFAULT is brought lower than approximately 2.5V the 8 VFAULT device output will be turned off and will auto-retry driving the output to see if the fault still exists. A PWM dimming function will be realized by adding an open collector/drain signal on this pin. Exposed Pad (bottom). Recommended to be connected to a large-area contiguous copper GND plane for effective thermal EP EP dissipation. Do not use as the ICs only electrical GND connection. 2 of 13 AL5817 August 2018 Diodes Incorporated www.diodes.com Document number: DS40391 Rev. 3 - 2 NEW PRODUCT