CAT4008
8-Channel Constant Current
LED Driver
Description
The CAT4008 is an 8 channel constant current driver for LED
billboard and other general display applications. LED channel
currents are programmed together via an external RSET resistor. Low
output voltage operation on the LED channels as low as 0.4 V (for 2 to
100 mA LED current) allows for more power efficient designs.
A high−speed 4−wire serial interface of up to 25 MHz clock
frequency controls each individual channel using a shift register and
latch configuration. A serial output data pin (SOUT) allows multiple
devices to be cascaded and programmed via one serial interface. The
device also includes a blanking control pin (BLANK) that can be used
to disable all channels independently of the interface.
Thermal shutdown protection is incorporated in the device to
disable the LED outputs if the die temperature exceeds a set limit.
The device is available in the 16−lead SOIC (narrow and wide), and
TSSOP packages.
Features
http://onsemi.com
1
SOIC−16
W SUFFIX
CASE 751BG
1
SOIC−16
V SUFFIX
CASE 751BH
TSSOP−16
Y SUFFIX
CASE 948AN
1
PIN CONNECTIONS
GND
SIN
SCLK
XLAT
LED1
LED2
LED3
LED4
1
VDD
RSET
SOUT
BLANK
LED8
LED7
LED6
LED5
•
•
•
•
•
•
•
•
8 Constant Current−sink Channels
Serial Interface up to 25 MHz Clock Frequency
3 V to 5.5 V Logic Supply
LED Current Range from 2 mA to 100 mA
LED Current set by External RSET Resistor
300 mV LED Dropout at 30 mA
Thermal Shutdown Protection
Available in 16−lead SOIC (150 and 300 mil wide), and TSSOP
Packages
•
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
16−Lead SOIC (W, V), TSSOP (Y)
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 13 of this data sheet.
•
•
•
•
Billboard Display
Marquee Display
Instrument Display
General Purpose Display
MARKING DIAGRAMS
A = Assembly Location
3 = Lead Finish
−
Matte−Tin
B = Product Revision (Fixed as “B”)
CAT4008W, CAT4008V, 4008Y = Device Code
Z or ZZ = Leave Blank
Y = Production Year (Last Digit)
M = Production Month (1-9, A, B, C)
XXX or XXXX = Last Three of Four Digits of
XXX or XXXX =
Assembly Lot Number
A3B
CAT4008VZ
YMXXXX
A3B
CAT4008WZ
YMXXXX
CAT4008W−T2
AB
4008YZZ
3YMXXX
CAT4008V−T1
©
Semiconductor Components Industries, LLC, 2010
CAT4008Y−T2 or
CAT4008Y−GT2
March, 2010
−
Rev. 2
1
Publication Order Number:
CAT4008/D
CAT4008
VIN
3 V to
5.5 V
20 mA
LED8
1
mF
VDD LED1 LED2
CONTROLLER
BLANK
LATCH
SIN
CLK
GND
CAT4008
SOUT
RSET
to next
device
3.09 kW
Figure 1. Typical Application Circuit
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
V
DD
Supply Voltage
Logic input/output voltage (SIN, SOUT, CLK, BLANK, LATCH)
LEDn voltage
DC output current on LED1 to LED8
Storage Temperature Range
Junction Temperature Range
Lead Soldering Temperature (10 sec.)
Rating
6
−0.3
V to V
DD
+0.3 V
6
150
−55
to +160
−40
to +150
300
Units
V
V
V
mA
_C
_C
_C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Table 2. RECOMMENDED OPERATING CONDITIONS
Parameter
V
DD
Voltage applied to LED1 to LED8
LED current RSET control range
Ambient Temperature Range
Range
3.0 to 5.5
0.4 to 5.5
up to 100
−40
to +85
Units
V
V
mA
_C
http://onsemi.com
2
CAT4008
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
Symbol
DC CHARACTERISTICS
I
LED−ACC
LED Current (any channel)
V
LED
= 1 V, R
SET
= 3.08 kW
V
LED
= 1 V, R
SET
= 1.54 kW
V
LED
= 1 V, R
SET
= 769
W
I
LED−MAT
LED Current Matching
(I
LED
−
I
LEDAVR
) / I
LEDAVR
V
LED
= 1 V, R
SET
= 3.08 kW
V
LED
= 1 V, R
SET
= 1.54 kW
V
LED
= 1 V, R
SET
= 769
W
ΔI
VDD
ΔI
VLED
I
DDOFF
I
DDON
I
LKG
R
LATCH
R
BLANK
V
IH
V
IL
V
HYS
I
IL
V
OH
V
OL
V
RSET
T
SD
T
HYST
LED current regulation vs. V
DD
LED current regulation vs. V
LED
Supply Current (all outputs off)
V
DD
within 4.5 V and 5.5 V
LED current 30 mA
V
LED
within 1 V and 3 V
LED current 30 mA
R
SET
= 3.08 kW
R
SET
= 769
W
Supply Current (all outputs on)
R
SET
= 3.08 kW
R
SET
= 769
W
LEDn output Leakage
LATCH Pull−down Resistance
BLANK Pull−up Resistance
Logic high input voltage
Logic low input voltage
Logic input hysteresis voltage
Logic Input leakage current
(CLK, SIN)
SOUT logic high output voltage
SOUT logic low output voltage
RSET Regulated Voltage
Thermal Shutdown
Thermal Hysteresis
V
I
= V
DD
or GND
I
OH
=
−1
mA
I
OL
= 1 mA
BLANK high, outputs off
−5
V
CC
−0.3
V
0.3
1.17
1.20
160
20
1.23
V
°C
°C
V
LED
= 5 V, outputs off
−1
100
100
0.7xV
DD
0.3xV
DD
0.1xV
DD
0
5
V
mA
V
180
180
−6.0
18
36
20
40
80
±1.5
±1.5
±2.0
±0.1
±0.05
2
5.5
2.5
6.2
1
300
300
mA
kW
kW
V
9
mA
8
%/V
%/V
mA
+6.0
%
22
44
mA
Name
(V
DD
= 5.0 V, T
AMB
= 25°C, over recommended operating conditions unless specified otherwise.)
Conditions
Min
Typ
Max
Units
http://onsemi.com
3
CAT4008
Table 4. TIMING CHARACTERISTICS
(For 3.0 V
≤
V
DD
≤
5.5 V, T
AMB
= 25°C, unless specified otherwise.)
Symbol
CLK
f
clk
t
cwh
t
cwl
SIN
t
ssu
t
sh
LATCH
t
lwh
T
lh
T
lsu
LEDn
t
ld
t
ls
t
lst
t
bd
t
lr
t
lf
LED1 Propagation delay
LED Propagation delay stagger
LED Propagation delay stagger total
BLANK Propagation delay
LED rise time (10% to 90%)
LED fall time (90% to 10%)
LATCH to LED1 off/on
LED(n) to LED(n+1)
LED1 to LED8
BLANK to LED(n) off/on
Pull−up resistor = 50
W
to 3.0 V
Pull−up resistor = 50
W
to 3.0 V
40
17
120
60
40
30
300
200
250
300
40
ns
ns
ns
ns
ns
ns
LATCH Pulse width
Hold time LATCH to CLK
Setup time LATCH to CLK
Channel Stagger Delay
20
4
400
ns
ns
ns
Setup time SIN to CLK
Hold time SIN to CLK
4
4
ns
ns
CLK Clock Frequency
CLK Pulse Width High
CLK Pulse Width Low
20
20
25
MHz
ns
ns
Name
Conditions
Min
(Note 1)
Typ
(Note 2)
Max
(Note 1)
Units
SOUT
t
or
t
of
t
od
SOUT rise time (10% to 90%)
SOUT fall time (90% to 10%)
Propagation delay time SOUT
C
L
= 15 pF
C
L
= 15 pF
CLK to SOUT
8
5
5
15
25
ns
ns
ns
1. All min and max values are guaranteed by design.
2. V
DD
= 5 V, LED current 30 mA.
VDD
1
mF
VDD
LED1
CONTROLLER
BLANK
LATCH
SIN
CLK
RSET
RSET
GND
CAT4008
LED8
SOUT
Rp
50
W
Rp
50
W
V1
Cl
15 pF
3V
Figure 2. Test Circuit for AC Characteristics
http://onsemi.com
4
CAT4008
1/f
clk
CLK
t
ssu
SIN
t
od
SOUT
t
lh
LATCH
t
lwh
t
lsu
t
sh
t
cwl
t
cwh
Figure 3. Serial Input Timing Diagram
t
ld
LATCH
t
bd
BLANK
t
ls
LED1
LED2
t
lst
= 7 t
ls
LED8
Figure 4. LED Output Timing Diagram
http://onsemi.com
5
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
