A8503 Datasheet | Allegro MicroSystems

Features and Benefits - Active current sharing between LED strings for ±0.6% accuracy and matching - Drives up to 12 series × 6 parallel = 72 LEDs (Vf = 3.2 V, If = 20 m A) at 5 V ▫ Each individual current sink is capable of 35 m A ▫ Adjustable overvoltage protection (OVP) - 600 k Hz to 2 MHz adjustable switching frequency ▫ Open or shorted LED string protection ▫ Open Schottky diode protection ▫ Overtemperature, cycle-by-cycle current limit, undervoltage, and soft start time-out protections ▫ Selectable latched/auto-restart protection modes - No audible MLCC noise during PWM dimming - No pull-up resistors required for LED modules that use ESD capacitors Continued on the next page… Package: 26 contact MLP/QFN (suffix EC) Not to scale Description The A8503 is a multi-output WLED/RGB LED driver for medium-size LCD backlighting. It integrates a current-mode boost converter with internal power switch and six current sinks. The boost converter can provide output voltages up to 47 V. The boost converter can drive up to 72 LEDs at 20 m A per LED with a battery voltage down to 5 V. The LED sinks are capable of sinking up to 35 m A each, and can also be paralleled together to achieve even higher LED currents. The A8503 provides protection against overvoltage, open diode, open or shorted LED string, and overtemperature. A dual level cycle-by-cycle current limit function provides soft start and protects against overloads. A soft start timeout monitor is provided to enhance protection when starting up into a fault condition. When the MODE pin is set low, the A8503 latches on a fault, and can be re-enabled only by cycling the input voltage, VIN, or by toggling the EN pin. Connecting the MODE pin high provides auto-restart after fault events. The A8503 features Continued on the next page… Applications - Notebook and sub-notebook displays - LCD monitors - LCD panels Typical Application VBAT 5 to 27 V VIN 4.3 to 5.5 V CBAT 4.7 µF 35 V D1 L1 10 µH ROVP COUT 2.2 µF SW SW...