General Description
The MAX6983 serial-interfaced LED driver provides 16
open-drain, constant-current-sinking LED driver outputs
rated at 36V. The MAX6983 operates from a 3V to 5.5V
supply. The MAX6983 supply and the LEDs' supply can
power up in any order. The constant-current outputs
are programmed together to up to 55mA using a single
external resistor. The MAX6983 operates with a 25Mb,
industry-standard, 4-wire serial interface.
The MAX6983 includes circuitry that automatically
detects open-circuit LEDs. Fault status is loaded into the
serial-interface shift register when LE goes high and is
automatically shifted out on DOUT when the next data
transmission is shifted in.
The MAX6983 includes a fail-safe feature for safety-
related applications, which blanks the display if the ser-
ial interface fails. If the serial interface becomes
inactive for more than 1s, all driver output latches are
automatically cleared. This turns off all LEDs connected
to the outputs. The shift register data is not disturbed.
The outputs remain off until the driver output latches are
updated with data turning them on, so recovery is auto-
matic if the transmission failure is temporary. The
watchdog function requires no software change to the
application driving the MAX6983.
The MAX6983 uses the industry-standard shift-register-
plus-latch-type serial interface. The driver accepts data
shifted into a 16-bit shift register using data input DIN
and clock input CLK. Input data appears at the output
DOUT 16 clock cycles later to allow cascading of multi-
ple MAX6983s. The latch-enable input, LE, loads the 16
bits of shift-register data into a 16-bit output latch to set
which LEDs are on and which are off. The output-
enable input, OE, gates all 16 outputs on and off, and is
fast enough to be used as a PWM input for LED intensi-
ty control.
The MAX6983 is one of a family of 12 shift-register-plus-
latch-type LED drivers. The family includes 8-port and
16-port types, with 5.5V- or 36V-rated LED outputs, with
and without open-circuit LED detection and watchdog.
All versions operate from a 3V to 5.5V supply, and are
specified over the -40C to +125C temperature range.
Features
25Mb Industry-Standard, 4-Wire Serial Interface
3V to 5.5V Logic Supply
16 Constant-Current LED Outputs Rated at 36V
Up to 55mA Continuous Current per Output
Output Current Programmed by Single Resistor
3% Current Matching Between Outputs
6% Current Matching Between ICs
Watchdog Clears Display if Interface Fails
Reports Open-Circuit LED Faults
High-Dissipation, 24-Pin Packages
-40C to +125C Temperature Range
MAX6983
16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog
________________________________________________________________ Maxim Integrated Products
1
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
V+
SET
DOUT
OE
LE
CLK
DIN
GND
TOP VIEW
OUT15
OUT14
OUT13
OUT12
OUT3
OUT2
OUT1
OUT0
16
15
14
13
9
10
11
12
OUT11
OUT10
OUT9
OUT8
OUT7
OUT6
OUT5
OUT4
TSSOP/PDIP
MAX6983AUG
MAX6983ANG
Pin Configuration
Ordering Information
19-3751; Rev 0; 7/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Typical Application Circuit and Selector Guide appear at
end of data sheet.
Applications
Variable Message Signs
Marquee Displays
Point-of-Order Signs
Traffic Signs
Gaming Features
Architectural Lighting
PART
TEMP RANGE
PIN- PACKAGE
PK G
C O D E
MAX6983AUG
-40C to +125C
24 TSSOP
--
MAX6983ANG
-40C to +125C
24 Narrow PDIP
--
MAX6983
16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Voltage (with respect to GND)
V+ .............................................................................-0.3V to +6V
OUT_ ......................................................................-0.3V to +40V
DIN, CLK, LE, OE, SE ..................................-0.3V to (V+ + 0.3V)
DOUT_ Current .................................................................10mA
OUT_ Sink Current ..............................................................60mA
Total GND Current ............................................................960mA
Continuous Power Dissipation (T
A
= +70C)
24-Pin PDIP (derate 13.3mW/C over +70C)............1067mW
24-Pin TSSOP (derate 12.2mW/C over +70C) .........975mW
Operating Temperature Range .........................-40C to +125C
Junction Temperature ......................................................+150C
Storage Temperature Range .............................-65C to +150C
Lead Temperature (soldering, 10s) .................................+300C
ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, V+ = 3V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 5V, T
A
= +25C.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Supply Voltage
V+
3.0
5.5
V
Output Voltage
V
OUT
36
V
Standby Current
(Interface Idle, All Output Ports
High Impedance, R
SET
= 360
)
I
+
All logic inputs at V+ or GND, DOUT_
unloaded
5.7
8
mA
Standby Current
(Interface Running, All Output
Ports High Impedance,
R
SET
= 360
)
I
+
f
CLK
= 25MHz, OE = V+, DIN and LE = V+
or GND, DOUT_ unloaded
6
6.5
mA
Supply Current
(Interface Idle, All Output Ports
Active Low, R
SET
= 360
)
I
+
All logic inputs at V+ or GND,
DOUT_ unloaded
18
25
mA
Input High Voltage
DIN_, CLK_, LE_, OE_
V
IH
0.7 x V+
V
Input Low Voltage
DIN_, CLK_, LE_, OE_
V
IL
0.3 x V+
V
Hysteresis Voltage
DIN_, CLK_, LE_, OE_
V
I
0.8
V
Input Leakage Current
DIN_, CLK_, LE_, OE_
I
IH
, I
IL
-1
+1
A
Output High-Voltage DOUT_
V
OH
I
SOURCE
= 4mA
V +
- 0.5V
V
Output Low-Voltage
V
OL
I
SINK
= 4mA
0.5
V
Output Current OUT_
I
OUT
V+ = 3V - 5.5V, V
OUT
= 0.8V - 2.5V,
R
SET
= 360
37
50
61
mA
Output Leakage Current OUT_
I
LEAK
OE = V+
1
A
Watchdog Timeout
t
WD
0.1
1
2.5
s
MAX6983
16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog
_______________________________________________________________________________________
3
5V TIMING CHARACTERISTICS
(Typical Operating Circuit, V+ = 4.5V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CLK_ Clock Period
t
CP
40
ns
CLK_ Pulse-Width High
t
CH
19
ns
CLK_ Pulse-Width Low
t
CL
19
ns
DIN_ Setup Time
t
DS
4
ns
DIN_ Hold Time
t
DH
8
ns
DOUT_ Propagation Delay
t
DO
12
32
ns
DOUT_ Rise and Fall Time
C
DOUT
= 10pF, 20% to 80%
10
ns
LE Setup Time
t
LS
10
ns
LE Rising to OUT_ Rising Delay
t
LRR
(Note 3)
100
ns
LE Rising to OUT_ Falling Delay
t
LRF
(Note 3)
300
ns
CLK_ Rising to OUT_ Rising
Delay
t
CRR
(Note 3)
100
ns
CLK_ Rising to OUT_ Falling
Delay
t
CRF
(Note 3)
310
ns
OE_ Rising to OUT_ Rising Delay
t
OEH
(Note 3)
100
ns
OE_ Falling to OUT_ Falling Delay
t
OEL
(Note 3)
320
ns
LED Output OUT_ Turn-On Fall
Time
t
f
80% to 20%; pullup resistor = 65
(Note 3)
120
ns
LED Output OUT_ Turn-Off Rise
Time
t
r
20% to 80%; pullup resistor = 65
(Note 3)
120
ns
MAX6983
16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog
4
_______________________________________________________________________________________
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(INTERFACE IDLE, ALL OUTPUTS OFF, R
SET
= 720
)
MAX6983 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.0
4.5
4.0
3.5
1.85
1.90
1.95
2.00
1.80
3.0
5.5
T
A
= +125
C
T
A
= +85
C
T
A
= -40
C
T
A
= +25
C
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(INTERFACE IDLE, ALL OUTPUTS OFF, R
SET
= 360
)
MAX6983 toc02
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.0
4.5
4.0
3.5
3.55
3.60
3.65
3.70
3.50
3.0
5.5
T
A
= +125
C
T
A
= +85
C
T
A
=-40
C
T
A
= +25
C
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(INTERFACE IDLE, ALL OUTPUTS ON, R
SET
= 720
)
MAX6983 toc03
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.0
4.5
4.0
3.5
20
25
30
35
40
45
T
A
= +125
C
T
A
= +85
C
T
A
= -40
C
T
A
= +25
C
15
3.0
5.5
Typical Operating Characteristics
(T
A
= +25C, unless otherwise noted.)
3.3V TIMING CHARACTERISTICS
(Typical Operating Circuit, V+ = 3V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CLK_ Clock Period
t
CP
52
ns
CLK_ Pulse-Width High
t
CH
24
ns
CLK_ Pulse-Width Low
t
CL
24
ns
DIN_ Setup Time
t
DS
4
ns
DIN_ Hold Time
t
DH
8
ns
DOUT_ Propagation Delay
t
DO
12
50
ns
DOUT_ Rise and Fall Time
C
DOUT
= 10pF, 20% to 80%
12
ns
LE Setup Time
t
LS
15
ns
LE Rising to OUT_ Rising Delay
(Note 3)
120
ns
LE Rising to OUT_ Falling Delay
(Note 3)
310
ns
C LK_ Ri si ng to OU T_ Ri si ng D el ay
(Note 3)
120
ns
C LK_ Ri si ng to OU T_ Fal l i ng D el ay
(Note 3)
330
ns
OE_ Rising to OUT_ Rising Delay
t
OEH
(Note 3)
120
ns
OE_ Falling to OUT_ Falling Delay
t
OEL
(Note 3)
330
ns
LED Output OUT_ Turn-On Fall
Time
t
f
80% to 20% (Note 3)
120
ns
LED Output OUT_ Turn-Off Rise
Time
t
r
20% to 80% (Note 3)
120
ns
Note 1: All parameters tested at T
A
= +25C. Specifications over temperature are guaranteed by design.
Note 2: See Figure 3.
Note 3: A 65
pullup resistor is connected from OUT_ to 5.5V.
MAX6983
16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog
_______________________________________________________________________________________
5
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(INTERFACE IDLE, ALL OUTPUTS ON, R
SET
= 360
)
MAX6983 toc04
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.0
4.5
4.0
3.5
20
25
30
35
40
T
A
= +125
C
45
15
3.0
5.5
T
A
= +85
C
T
A
= -40
C
T
A
= +25
C
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 720
, V+ = 3.3V)
MAX6983 toc05
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
5
10
15
20
25
30
T
A
= -40
C
T
A
= +25
C
T
A
= +85
C
T
A
= +125
C
0
0
3.0
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 360
, V+ = 3.3V)
MAX6983 toc06
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
10
20
30
40
50
60
T
A
= -40
C
T
A
= +25
C
T
A
= +85
C
T
A
= +125
C
0
0
3.0
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 720
, V+ = 5.0V)
MAX6983 toc07
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
5
10
15
20
25
30
T
A
= -40
C
T
A
= +25
C
T
A
= +85
C
T
A
= +125
C
0
0
3.0
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 360
V+ = 5.0V)
MAX6983 toc08
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
10
20
30
40
50
60
T
A
= -40
C
T
A
= +25
C
T
A
= +85
C
T
A
= +125
C
0
0
3.0
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 720
, V
OUT
= 2V)
MAX6983 toc09
PORT OUTPUT VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
5.0
4.5
4.0
3.5
23.5
24.0
24.5
25.0
T
A
= +125
C
T
A
= +85
C
T
A
= +25
C
T
A
= -40
C
23.0
3.0
5.5
PORT OUTPUT CURRENT vs. PORT OUTPUT VOLTAGE
(R
SET
= 360
, V
OUT
= 2V)
MAX6983 toc10
SUPPLY VOLTAGE (V)
PORT OUTPUT CURRENT (mA)
5.0
4.5
4.0
3.5
47
48
49
T
A
= -40
C
T
A
= +25
C
T
A
= +85
C
T
A
= +125
C
46
3.0
5.5
PORT OUTPUT CURRENT vs. R
SET
RESISTANCE
(V+ = 5.0V)
MAX6983 toc11
R
SET
RESISTANCE (k
)
PORT OUTPUT CURRENT (mA)
4
3
2
1
10
20
30
40
50
0
0
5
Typical Operating Characteristics (continued)
(T
A
= +25C, unless otherwise noted.)
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