4-Channel LED Backlight Controller
• 4 Channels
• 5.5V to 30V Input Voltage Supply
• Drive up to 68 (17x4) White LEDs
The APW7228B is a high efficiency driver for 4 channels
of LEDs. It contains an adjustable-frequency current-
mode PWM step-up controller, a 5V linear regulator, dim-
ming control circuit and eight regulated current source
• Current Match (Balance) ±1% (Typ.)
• Current Accuracy ±1% (Typ.)
The APW7228B is capable of driving typically 68 (4x17)
• External PWM Input from 100Hz to 50kHz Dim- pieces of 3.5V/160mA LEDs. It contains 4 channels of
voltage controlled current sources with typical currents
• Time Shift PWM Dimming Control
matching of +1%, which compensate for the non-unifor-
• Random Channel Selection for Dynamic Opera- mity effect of forward voltages variance in the LED stacks.
• Adjustable Switching Frequency
To minimize the voltage headroom and power loss in the
typical multi-strings operation, the APW7228B features a
dynamic headroom control that monitors the highest LED
- String Open Circuit Detection
forward voltage string and uses its feedback signal for
- String Short Circuit Detection
- Over-Temperature Protection
The APW7228B features extensive protection functions
- Over-Voltage Protection
that include LED strings open and short circuit detections,
• Available in TSSOP-16P, SOP-16, DIP-16 and Output Over-Voltage Protection (OVP) and Over-Tempera-
• Lead Free and Green Devices Available
ture Protection (OTP).
The APW7228B is available in TSSOP-16P, SOP-16, DIP-
16 and QFN4x4-16A package.
• NB LED Backlight
• LCD Monitor Backlight
• LCD TV LED Backlight
Simplified Application Circuit
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and
advise customers to obtain the latest version of relevant information to verify before placing orders.
Copyright © ANPEC Electronics Corp.
Rev. A.9 - Mar., 2013