A8519 and A8519-1 Wide Input Voltage Range, High-Efficiency, Fault-Tolerant LED Driver FEATURES AND BENEFITS DESCRIPTION The A8519 is a multi-output LED driver for small-size LCD Automotive AEC-Q100 qualified backlighting. It integrates a current-mode boost converter Fully integrated 42 V MOSFET for boost converter with internal power switch and four current sinks. The boost Fully integrated LED current sinks converter can drive up to 44 white LEDs, 11 LED per string, at Withstands surge input up to 40 V for load dump IN 100 mA. The LED sinks can be paralleled together to achieve Operates down to 3.9 V (max) for idle stop IN higher LED currents up to 400 mA. The A8519 operates from Drives four strings of LEDs a single power supply from 4.5 to 40 V, which allows the part Maximum output voltage 40 V to withstand load dump conditions encountered in automotive Up to 11 white LEDs in series systems. Drive current for each string is 100 mA Programmable boost switching frequency (200 kHz to The A8519 can control LED brightness through a digital 2.15 MHz) (PWM) signal. An LED brightness contrast ratio of 10,000:1 Synchronized boost switching frequency option (320 kHz can be achieved using PWM dimming at 100 Hz a higher ratio to 2.3 MHz) of 100,000:1 is possible when using a combination of PWM Dithering of boost switching frequency to reduce EMI and analog dimming. Extremely high LED contrast ratio If required, the A8519 can drive an external P-channel 10,000:1 using PWM dimming alone MOSFET to disconnect input supply from the system in the 100,000:1 when combining PWM and analog dimming event of a fault. The A8519 provides protection against output Continued on the next page short, overvoltage, open or shorted diode, open or shorted LED pin, and overtemperature. A cycle-by-cycle current limit PACKAGES: protects the internal boost switch against high-current overloads. 20-Pin TSSOP with Exposed 28-Pin QFN with Exposed Continued on the next page Thermal Pad (suffix LP) Thermal Pad (suffix ET) APPLICATIONS: Automotive infotainment backlighting Automotive cluster Automotive center stack Not to scale Typical Application Diagram V IN Optional L1 V> V D1 OUT IN Q1 R SC RADJ ROVP C IN C C OUT1 OUT2 GATE SW VOUT VSENSE VIN OVP VDD V C LED1 CVDD A8519 R LED2 PU FAULT LED3 PWM LED4 APWM CLKOUT COMP ISET FSET AGND PGND R Z C P R RFSET ISET C Z GND Typical Application Circuit Showing VOUT-to-Ground Short Protection Using Optional P-Channel MOSFET A8519-DS, Rev. 10 March 14, 2019 MCO-0000554A8519 and Wide Input Voltage Range, High-Efficiency, Fault-Tolerant LED Driver A8519-1 FEATURES AND BENEFITS (CONTINUED) DESCRIPTION (CONTINUED) Excellent input voltage transient response at lowest PWM duty cycle The A8519 has a synchronization pin that allows boost switching Gate driver for optional P-channel MOSFET input disconnect switch frequencies to be synchronized in the range of 320 kHz to 2.3 MHz. LED current accuracy 0.7% The high switching frequency allows the converter to operate above the LED string current-matching accuracy 0.8% AM radio band. The IC contains a clock output pin that allows other Protection against: converters to be synchronized to the A8519s boost switching frequency. Shorted boost switch, inductor or output capacitor The A8519 employs hysteresis control to help regulate the LED Shorted FSET or ISET resistor current at extremely short PWM on-time. The A8519-1 is identical Open or shorted LED pins and LED strings to the A8519, except that it uses a smaller hysteresis window to Open boost diode reduce output voltage ripple during PWM dimming. Overtemperature SELECTION GUIDE Operating Ambient Hysteresis Leadframe 1 Part Number Temperature Range Package Packaging Window Plating T (C) A A8519KLPTR-T 40 to 125 350 mV 20-pin TSSOP with exposed thermal pad 4000 pieces per reel 100% matte tin 28-pin 5 5 mm QFN with exposed ther- A8519KETTR-R 40 to 125 350 mV 1500 pieces per reel 100% matte tin mal pad and sidewall plated A8519KLPTR-T-1 40 to 125 150 mV 20-pin TSSOP with exposed thermal pad 4000 pieces per reel 100% matte tin 28-pin 5 5 mm QFN with exposed ther- A8519KETTR-R-1 40 to 125 150 mV 1500 pieces per reel 100% matte tin mal pad and sidewall plated 1 Contact Allegro for additional packing options. 2 ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Unit LEDx Pins V x = 1, 2, 3, or 4 0.3 to 40 V LEDx OVP Pin V 0.3 to 40 V OVP VIN, VOUT Pins V V 0.3 to 40 V IN, OUT VSENSE, GATE Pins V V V 7.4 to V +0.4 V SENSE, GATE IN IN Continuous 0.6 to 42 V 3 SW Pin V SW t < 50 ns 1 to 48 V FAULT Pin V 0.3 to 40 V FAULT APWM, PWM, CLKOUT, COMP, 0.3 to 5.5 V FSET, ISET, VDD Pins Operating Ambient Temperature T K temperature range 40 to 125 C A Maximum Junction Temperature T 150 C J(max) Storage Temperature T 55 to 150 C stg 2 Operation at levels beyond the ratings listed in this table may cause permanent damage to the device. The absolute maximum ratings are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the electrical characteristics table is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability. 3 SW DMOS is self-protecting and will conduct when V exceeds 48 V. SW 2 Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com