CAT4026_11 Datasheet, PDF (1/14 Pages) ON Semiconductor – 6-Channel LED Controller

CAT4026
6-Channel LED Controller
with Fault Diagnostics for
Large Panel LED
Backlighting
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.
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.
The device will automatically enter low current shutdown mode by
taking the PWM pin low for an extended length of time.
Features
• 6 Channel LED Controller
• 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
• Thermal Shutdown Protection
• Automatic Inactivity Power Down Mode
• SOIC−28L Package
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Typical Applications
• LCD−TV LED Backlighting
• LED General Lighting
http://onsemi.com
SOIC−28
V SUFFIX
CASE 751BM
PIN CONNECTIONS
VDD
1
28
GND
PWM
2
27
SCA
ANLG
3
26
VCS
BASE1
4
25
BASE6
RSET1
5
24
RSET6
BASE2
6
23
BASE5
RSET2
7
22
RSET5
BASE3
8
21
BASE4
RSET3
9
20
RSET4
OCA
10
19
FLT−OCA
C1
11
18
C3
N.C.
12
17
FLT−SCA
VA
13
16
IFB
N.C.
14
15
VC
(Top View)
MARKING DIAGRAM
L3A
CAT4026V
YYWWXXXX
L
= Assembly Location Code
3
= Mark “3” for (lead finish Matte−Tin)
A
= Product Revision: Fixed as “A”
CAT4026V = Specific Device Code
YY
= Production Year (Last Two Digits)
WW
= Production Week (Two Digits)
XXXX = Last Four Digits of Assembly Lot Number
ORDERING INFORMATION
Device
CAT4026V−T1
(Note 1)
Package
SOIC−28
(Pb−Free)
Shipping
1,000/
Tape & Reel
1. Matte Tin Plated Finish (RoHS−compliant)
© Semiconductor Components Industries, LLC, 2011
1
May, 2011 − Rev. 5
Publication Order Number:
CAT4026/D