MAX6979AUG+ Maxim Integrated Products, MAX6979AUG+ Datasheet

IC LED DRIVER LINEAR 24-TSSOP

MAX6979AUG+

Manufacturer Part Number
MAX6979AUG+
Description
IC LED DRIVER LINEAR 24-TSSOP
Manufacturer
Maxim Integrated Products
Type
Linear (Serial Interface)r
Datasheet

Specifications of MAX6979AUG+

Constant Current
Yes
Topology
16-Bit Shift Register, Open Drain, PWM
Number Of Outputs
16
Internal Driver
Yes
Type - Primary
General Purpose
Voltage - Supply
3 V ~ 5.5 V
Voltage - Output
5.5V
Mounting Type
Surface Mount
Package / Case
24-TSSOP
Operating Temperature
-40°C ~ 125°C
Current - Output / Channel
55mA
Internal Switch(s)
No
Number Of Segments
32
Low Level Output Current
60 mA
Operating Supply Voltage
3 V to 5.5 V
Maximum Supply Current
25 mA
Maximum Power Dissipation
975 mW
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Frequency
-
Efficiency
-
Lead Free Status / Rohs Status
 Details
The MAX6979 serial-interfaced LED driver provides 16
open-drain, constant-current-sinking LED driver outputs
rated at 5.5V. The MAX6979 operates from a 3V to 5.5V
supply. The MAX6979 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 MAX6979 operates with a 25Mb,
industry-standard, 4-wire serial interface.
The MAX6979 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 MAX6979 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 MAX6979.
The MAX6979 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 MAX6979s. 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 MAX6979 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.
19-3703; Rev 1; 12/10
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
16-Port, 5.5V Constant-Current LED Driver with
Variable Message Signs
Marquee Displays
Point-of-Order Signs
Traffic Signs
Gaming Features
Architectural Lighting
________________________________________________________________ Maxim Integrated Products
General Description
LED Fault Detection and Watchdog
Applications
o 25Mb Industry-Standard, 4-Wire Serial Interface at 5V
o 3V to 5.5V Logic Supply
o 16 Constant-Current LED Outputs Rated at 5.5V
o Up to 55mA Continuous Current per Output
o Output Current Programmed by Single Resistor
o 3% Current Matching Between Outputs
o 6% Current Matching Between ICs
o Watchdog Clears Display if Interface Fails
o Reports Open-Circuit LED Faults
o High-Dissipation, 24-Pin Packages
o -40°C to +125°C Temperature Range
+ Denotes a lead(Pb)-free/RoHS-compliant package.
Typical Application Circuit and Selector Guide appear at
end of data sheet.
MAX6979AUG+
MAX6979APG+
TOP VIEW
PART
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
GND
CLK
DIN
LE
10
11
12
1
2
3
4
5
6
7
8
9
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
Ordering Information
TSSOP/PDIP
+
MAX6979AUG
MAX6979APG
Pin Configuration
24
23
22
21
20
19
18
17
16
15
14
13
V+
SET
DOUT
OE
OUT15
OUT14
OUT13
OUT12
OUT11
OUT10
OUT9
OUT8
PIN-PACKAGE
24 TSSOP
24 PDIP
Features
1

Related parts for MAX6979AUG+

MAX6979AUG+ Summary of contents

Page 1

... Current Matching Between ICs o Watchdog Clears Display if Interface Fails o Reports Open-Circuit LED Faults o High-Dissipation, 24-Pin Packages o -40°C to +125°C Temperature Range PART MAX6979AUG+ MAX6979APG+ + Denotes a lead(Pb)-free/RoHS-compliant package. Typical Application Circuit and Selector Guide appear at end of data sheet. TOP VIEW ...

Page 2

Constant-Current LED Driver with LED Fault Detection and Watchdog ABSOLUTE MAXIMUM RATINGS Voltage (with respect to GND) V+ .............................................................................-0.3V to +6V OUT_ ........................................................................-0.3V to +6V DIN, CLK, LE, OE, SE ..................................-0.3V to (V+ + 0.3V) DOUT_ Current .................................................................±10mA ...

Page 3

Constant-Current LED Driver with LED Fault Detection and Watchdog 5V TIMING CHARACTERISTICS ( Typical Operating Circuit , V+ = 4.5V to 5.5V, T PARAMETER SYMBOL CLK Clock Period CLK Pulse-Width High CLK Pulse-Width Low DIN Setup Time DIN ...

Page 4

Constant-Current LED Driver with LED Fault Detection and Watchdog 3.3V TIMING CHARACTERISTICS ( Typical Operating Circuit , 5.5V, T PARAMETER SYMBOL CLK Clock Period CLK Pulse-Width High CLK Pulse-Width Low DIN Setup Time DIN ...

Page 5

Constant-Current LED Driver with LED Fault Detection and Watchdog (T = +25°C, unless otherwise noted.) A SUPPLY CURRENT vs. SUPPLY VOLTAGE (INTERFACE IDLE, ALL OUTPUTS ON 360Ω) SET +125° +85°C A ...

Page 6

Constant-Current LED Driver with LED Fault Detection and Watchdog PIN NAME 1 GND Ground 2 DIN Serial-Data Input. Data is loaded into the internal 16-bit shift register on CLK’s rising edge. 3 CLK Serial-Clock Input. Data is loaded ...

Page 7

Constant-Current LED Driver with LED Fault Detection and Watchdog LE CLK DIN DOUT OE OUT_ Figure 2. 4-Wire Serial-Interface Timing Diagram The 4-wire serial interface comprises a 16-bit shift reg- ister and a 16-bit transparent latch. The shift ...

Page 8

Constant-Current LED Driver with LED Fault Detection and Watchdog LE t LRF OUT_ LE t LRR OUT_ CLK t CRF OUT_ CLK t CRR OUT_ Figure 3. LE and CLK to OUT_ Timing The MAX6979 includes a watchdog ...

Page 9

Constant-Current LED Driver with LED Fault Detection and Watchdog Table 1. 4-Wire Serial-Interface Truth Table SHIFT-REGISTER SERIAL CLOCK CONTENTS DATA INPUT INPUT CLK … DIN … R ...

Page 10

Constant-Current LED Driver with LED Fault Detection and Watchdog NO. OF PART OUTPUTS MAX6968 MAX6977 8 MAX6978 MAX6970 8 MAX6981 MAX6980 MAX6969 MAX6984 16 MAX6979 MAX6971 MAX6982 16 MAX6983 +5V MAX6979 µC V+ OUT0 SCLK CLK OUT1 OUT2 ...

Page 11

Constant-Current LED Driver with LED Fault Detection and Watchdog Chip Information PROCESS: BiCMOS ______________________________________________________________________________________ Package Information For the latest package outline information and land patterns www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package ...

Page 12

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2010 Maxim Integrated Products DESCRIPTION Maxim is a registered trademark of Maxim Integrated Products, Inc ...

Related keywords