ACT6358 High-Efficiency, 40V Step-Up WLED Bias Supply FEATURES GENERAL DESCRIPTION High-Efficiency DC/DC WLED Bias Supply The ACT6358 step-up DC/DC converter drives white LEDs with an externally programmable constant current. Internal 40V, 0.55 Power MOSFET This device features integrated, 40V power MOSFETs Up to 10 WLEDs per String that are capable of driving up to ten white LEDs in series, 1A Peak Current providing inherent current matching for uniform Supports Analog and PWM LED Dimming brightness. WLED brightness adjustment is easily Integrated Over-Voltage Protection (OVP) achieved via a dual-function pin, which accepts either a Programmable Soft-Start Function PWM or an analog dimming control signal. Thermal Shutdown The ACT6358 features a variety of protection circuits, Cycle-by-Cycle Over Current Protection including integrated over voltage protection (OVP), Tiny TDFN33-8 Package programmable soft-start, cycle-by-cycle current limiting, and thermal shutdown protection circuitry. The ACT6358 has a 1A current limit. It is available in a APPLICATIONS small 3mm x 3mm 8-pin TDFN33-8. TFT LCD Displays Smart Phones Portable Media Players GPS/Personal Navigation Devices SIMPLIFIED APPLICATION CIRCUIT Data Sheet Rev. 2.0, January 19, 2020 Subject to change without notice 1 of 10 www.qorvo.com ACT6358 High-Efficiency, 40V Step-Up WLED Bias Supply ORDERING INFORMATION PART NUMBER CURRENT LIMIT TEMPERATURE RANGE PACKAGE PINS PACKING ACT6358NH-T 1A -40C to 85C TDFN33-8 8 TAPE & REEL PIN CONFIGURATION TDFN33-8 PIN DESCRIPTIONS PIN NAME DESCRIPTION 1 G Ground 2 IN Supply Input Enable Control. Drive to a logic high to enable the device. Connect to a logic low to disable the 3 EN device. EN should not be left floating connect EN to IN when unused. Brightness Control. Multifunction pin accepts either a PWM or analog control signal. When using a PWM control signal, the best results are achieved when the PWM frequency is in the 100Hz to 4 BC 10kHz range and when the PWM high voltage is 1.8V or higher. When using an analog control signal, the best results are achieved when the control voltage is in the 0V to 1.8V range. Feedback Input. Connect this pin to the cathode of the bottom LED, and a current feedback resistor 5 FB between this pin and G to set the LED bias current. Soft Start Control Input. Connect a capacitor from this pin to G to program the soft start duration. SS 6 SS is internally discharged when IC the is disabled Over Voltage Protection Input. The IC is automatically disabled when the voltage at this pin 7 OV exceeds 1.21V. Connect OV to the center point of a resistive voltage divider connected across the LED string. 8 SW Switch Output. Connect this pin to the inductor and the Schottky diode. EP EP Exposed Pad. Connect to ground. Data Sheet Rev. 2.0, January 19, 2020 Subject to change without notice 2 of 10 www.qorvo.com