ACT6357/ACT6358
www.DataSheet4U.com
Rev0, 03-Feb-08 Advanced Product Information―All Information Subject to Change
Hig...
ACT6357/ACT6358
www.DataSheet4U.com
Rev0, 03-Feb-08 Advanced Product Information―All Information Subject to Change
High-Efficiency, 40V Step-Up WLED Bias Supplies FEATURES
High-Efficiency DC/DC WLED Bias Supply Internal 40V, 0.55Ω Power
MOSFET Up to 10 WLEDs per String Two Peak Current Options:
− ACT6357: 0.5A − ACT6358: 1A
GENERAL DESCRIPTION
The ACT6357 and ACT6358 step-up DC/DC converters drive white LEDs with an externally programmable constant current. These devices feature integrated, 40V power
MOSFETs that are capable of driving up to ten white LEDs in series, providing inherent current matching for uniform brightness. WLED brightness adjustment is easily achieved via a dual-function pin, which accepts either a PWM or an analog dimming control signal. The ACT6357 and ACT6358 feature a variety of protection circuits, including integrated over
voltage protection (OVP), programmable soft-start, cycleby-cycle current limiting, and thermal shutdown protection circuitry. The ACT6357 has 500mA current limit, while the ACT6358 has 1A current limit. Both parts are available in a small 3mm x 3mm 8-pin TDFN33-8.
Supports Analog and PWM LED Dimming Integrated Over-
Voltage Protection (OVP) Programmable Soft-Start Function Thermal Shutdown Cycle-by-Cycle Over Current Protection Tiny TDFN33-8 Package
APPLICATIONS
TFT LCD Displays Smart Phones Portable Media Players GPS/Personal Navigation Devices
SIMPLIFIED APPLICATION CIRCUIT
L1 Up to 10 WLEDs OUT R...