High Voltage 8-CH LED Driver
The RT8561C is a 40V 8-CH LED driver capable of
delivering 30mA to each channel with 10 LEDs (3.6V per
diode), for a total of 80 LEDs with one driver. The RT8561C
is a current mode boost converter that operates at 1MHz,
with a wide VIN range from 4.5V to 24V and an on chip
current switch rated at 2.5A.
The PWM output voltage loop regulates the LED pins to
0.6V with an auto adjustment circuit allowing voltage
mismatches between LED strings. The RT8561C automati
cally detects and disconnects any unconnected and/or
broken strings during operation from the PWM loop to
prevent VOUT from over voltage.
The 1.5% matched LED currents on all channels can be
simply programmed with a resistor or a current sink. A
very high contrast ratio true digital PWM dimming can be
achieved by driving the PWM pin with a PWM signal.
Other protection features include programmable output
over voltage protection, LED current limit, PWM switch
current limit and thermal shutdown.
The RT8561C is available in a WQFN-24L 4x4 package.
QW : WQFN-24L 4x4 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
E4= : Product Code
YMDNN : Date Code
z High Voltage : VIN up to 24V, VOUT up to 40V
z Programmable Channel Current from 10mA to 30mA
and Matched to 1.5%
z Current Mode PWM 1MHz Boost Converter
z Easy and High Accuracy Digital Dimming by PWM
z Programmable Soft-Start
z Automatic Detection of Unconnected and/or Broken
z Programmable Over Voltage Protection
z Disconnects LED in Shutdown
z No Power Sequence Concern
z VIN Under Voltage Lockout
z Over Temperature Protection
z Current Limiting Protection
z Small 24-Lead WQFN Package
z RoHS Compliant and Halogen Free
z UMPC and Notebook Computer Backlight
z GPS, Portable DVD Backlight
z Desk Lights and Room Lighting
24 23 22 21 20 19
25 13 EN
7 8 9 10 11 12
DS8561C-00 April 2011