Rainbow Electronics MAX6983 - 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 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 -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
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 -40°C to +125°C 24 TSSOP —
MAX6983ANG -40°C to +125°C 24 Narrow PDIP —