CAT4026
6-Channel LED Controller
with Fault Diagnostics for
Large Panel LED
Backlighting
http://onsemi.com
Description
The CAT4026 is a high performance, large panel LED controller
designed to control six constant current high voltage LED strings.
Added control circuitry monitors the lowest cathode voltage and
generates a feedback control signal to an external Switch Mode Power
Supply (SMPS) to provide a low cost and efficient solution for large
panel high voltage LED backlighting.
SOIC−28
V SUFFIX
Each LED channel current is accurately matched and controlled by
sensing an external resistor in series with a low cost bipolar power
transistor. This allows current and heat dissipation concerns to be
mitigated from the CAT4026 device package.
For added system reliability, both Open−Cathode−Anode (OCA)
and Shorted−Cathode−Anode (SCA) fault detection circuitry has been
included along with independent Fault flag logic outputs for
diagnostic purposes.
LED current dimming in all six channels can be precisely controlled
by either a Pulse Width Modulation signal via the PWM input pin or
by an analog dimming voltage applied at the ANLG pin. In addition
the ANLG pin provides a convenient method for limiting the overall
maximum power dissipation in the event of excessive LED shorting
within any LED string.
CASE 751BM
PIN CONNECTIONS
1
GND
VDD
PWM
ANLG
BASE1
RSET1
BASE2
RSET2
BASE3
RSET3
OCA
SCA
VCS
BASE6
RSET6
BASE5
RSET5
BASE4
RSET4
FLT−OCA
C3
C1
FLT−SCA
IFB
VC
N.C.
VA
N.C.
The device will automatically enter low current shutdown mode by
taking the PWM pin low for an extended length of time.
(Top View)
MARKING DIAGRAM
Features
• 6 Channel LED Controller
L3A
CAT4026V
YYWWXXXX
• Adaptive Feedback Control to External SMPS for Better Efficiency
• PWM and Analog Mode Dimming
• Short Cathode−Anode (SCA) Fault Protection
• Open Cathode−Anode (OCA) Fault Protection
• Over−Voltage Protection
L
3
A
= Assembly Location Code
= Mark “3” for (lead finish Matte−Tin)
= Product Revision: Fixed as “A”
• Thermal Shutdown Protection
• Automatic Inactivity Power Down Mode
• SOIC−28L Package
CAT4026V = Specific Device Code
YY
WW
XXXX
= Production Year (Last Two Digits)
= Production Week (Two Digits)
= Last Four Digits of Assembly Lot Number
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Typical Applications
ORDERING INFORMATION
• LCD−TV LED Backlighting
• LED General Lighting
Device
Package
Shipping
CAT4026V−T1
(Note 1)
SOIC−28
(Pb−Free)
1,000/
Tape & Reel
1. Matte Tin Plated Finish (RoHS−compliant)
© Semiconductor Components Industries, LLC, 2010
1
Publication Order Number:
CAT4026/D
February, 2010 − Rev. 2