Rainbow Electronics MAX6983 User Manual

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 safety­related applications, which blanks the display if the ser­ial 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 auto­matic 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-register­plus-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 multi­ple 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 output­enable input, OE, gates all 16 outputs on and off, and is
fast enough to be used as a PWM input for LED intensi­ty control.

The MAX6983 is one of a family of 12 shift-register-plus­latch-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 -40°C to +125°C 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
♦ -40°C to +125°C Temperature Range

MAX6983

16-Port, 36V Constant-Current LED Driver with

LED Fault Detection and Watchdog

________________________________________________________________ Maxim Integrated Products 1

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

MAX6983AUG -40°C to +125°C 24 TSSOP —

MAX6983ANG -40°C to +125°C 24 Narrow PDIP —

PK G

C O D E

TOP VIEW

GND

DIN

CLK

OUT0

OUT1

OUT2

OUT4

OUT5

OUT6

1

2

3

4

5

6

MAX6983AUG

7

MAX6983ANG

8

9

10

11

12

TSSOP/PDIP

V+

24

SET

23

DOUT

22

OELE

21

20

OUT15

19

OUT14

18

OUT13

17

OUT12OUT3

16

OUT11

15

OUT10

14

OUT9

13

OUT8OUT7

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 (TA= +70°C)

24-Pin PDIP (derate 13.3mW/°C over +70°C)............1067mW

24-Pin TSSOP (derate 12.2mW/°C over +70°C) .........975mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

ELECTRICAL CHARACTERISTICS

(Typical Operating Circuit, V+ = 3V to 5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at V+ = 5V, TA= +25°C.)

(Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Operating Supply Voltage V+ 3.0 5.5 V

Output Voltage V

Standby Current
(Interface Idle, All Output Ports
High Impedance, R

Standby Current
(Interface Running, All Output
Ports High Impedance,
R

= 360Ω)

SET

Supply Current
(Interface Idle, All Output Ports
Active Low, R

Input High Voltage
DIN_, CLK_, LE_, OE_

Input Low Voltage
DIN_, CLK_, LE_, OE_

Hysteresis Voltage
DIN_, CLK_, LE_, OE_

Input Leakage Current
DIN_, CLK_, LE_, OE_

Output High-Voltage DOUT_ V

Output Low-Voltage V

Output Current OUT_ I

Output Leakage Current OUT_ I

Watchdog Timeout t

SET

= 360Ω)

SET

= 360Ω)

OUT

V

V

∆V

I

IH

OUT

LEAK

WD

I

+

I

+

I

+

IH

, I

OH

OL

IL

I

IL

All logic inputs at V+ or GND, DOUT_
unloaded

f

CLK

or GND, DOUT_ unloaded

All logic inputs at V+ or GND,
DOUT_ unloaded

I

SOURCE

I

SINK

V+ = 3V - 5.5V, V
R

OE = V+ 1 µA

= 25MHz, OE = V+, DIN and LE = V+

= 4mA

= 4mA 0.5 V

= 360Ω

SET

36 V

5.7 8 mA

6 6.5 mA

18 25 mA

0.7 x V+ V

0.3 x V+ V

0.8 V

-1 +1 µA

V +

- 0.5V

= 0.8V - 2.5V,

OUT

37 50 61 mA

0.1 1 2.5 s

V

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, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CLK_ Clock Period t

CLK_ Pulse-Width High t

CLK_ Pulse-Width Low t

DIN_ Setup Time t

DIN_ Hold Time t

DOUT_ Propagation Delay t

DOUT_ Rise and Fall Time C

LE Setup Time t

LE Rising to OUT_ Rising Delay t

LE Rising to OUT_ Falling Delay t

CLK_ Rising to OUT_ Rising
Delay

CLK_ Rising to OUT_ Falling
Delay

OE_ Rising to OUT_ Rising Delay t
OE_ Falling to OUT_ Falling Delay t

LED Output OUT_ Turn-On Fall
Time

LED Output OUT_ Turn-Off Rise
Time

CP

CH

CL

DS

DH

DO

LRR

LRF

t

CRR

t

CRF

OEH

OEL

LS

t

t

f

r

DOUT

(Note 3) 100 ns

(Note 3) 300 ns

(Note 3) 100 ns

(Note 3) 310 ns

(Note 3) 100 ns

(Note 3) 320 ns

80% to 20%; pullup resistor = 65Ω (Note 3) 120 ns

20% to 80%; pullup resistor = 65Ω (Note 3) 120 ns

40 ns

19 ns

19 ns

4ns

8ns

12 32 ns

= 10pF, 20% to 80% 10 ns

10 ns

MAX6983

16-Port, 36V Constant-Current LED Driver with
LED Fault Detection and Watchdog

4 _______________________________________________________________________________________

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

3.3V TIMING CHARACTERISTICS

(Typical Operating Circuit, V+ = 3V to 5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

Note 1: All parameters tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2: See Figure 3.
Note 3: A 65Ω pullup resistor is connected from OUT_ to 5.5V.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CLK_ Clock Period t

CLK_ Pulse-Width High t

CLK_ Pulse-Width Low t

DIN_ Setup Time t

DIN_ Hold Time t

DOUT_ Propagation Delay t

CP

CH

CL

DS

DH

DO

DOUT_ Rise and Fall Time C

LE Setup Time t

LS

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
OE_ Falling to OUT_ Falling Delay t

LED Output OUT_ Turn-On Fall
Time

LED Output OUT_ Turn-Off Rise
Time

OEH

OEL

t

f

t

r

52 ns

24 ns

24 ns

4ns

8ns

12 50 ns

= 10pF, 20% to 80% 12 ns

DOUT

15 ns

(Note 3) 120 ns

(Note 3) 330 ns

80% to 20% (Note 3) 120 ns

20% to 80% (Note 3) 120 ns

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(INTERFACE IDLE, ALL OUTPUTS OFF, R

2.00

TA = +125°C

1.95

1.90

SUPPLY CURRENT (mA)

1.85

1.80

3.0 5.5
SUPPLY VOLTAGE (V)

TA = +85°C

TA = +25°C

TA = -40°C

= 720Ω)

SET

5.04.54.03.5

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(INTERFACE IDLE, ALL OUTPUTS OFF, R

3.70

MAX6983 toc01

3.65

3.60

SUPPLY CURRENT (mA)

3.55

3.50

TA = +125°C

TA =-40°C

3.0 5.5
SUPPLY VOLTAGE (V)

TA = +85°C

TA = +25°C

= 360Ω)

SET

5.04.54.03.5

(INTERFACE IDLE, ALL OUTPUTS ON, R

MAX6983 toc02

SUPPLY CURRENT (mA)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

= 720Ω)

45

40

TA = +125°C

35

30

25

20

TA = -40°C

15

3.0 5.5
SUPPLY VOLTAGE (V)

SET

TA = +85°C

TA = +25°C

5.04.54.03.5

MAX6983 toc03