MAX6956_09 Datasheet, PDF (1/24 Pages) Maxim Integrated Products – 2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or 28-Port LED Display Driver and I/O Expander

19-2414; Rev 3; 3/09
2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or
28-Port LED Display Driver and I/O Expander
General Description
The MAX6956 compact, serial-interfaced LED display
driver/I/O expander provide microprocessors with up to
28 ports. Each port is individually user configurable to
either a logic input, logic output, or common-anode
(CA) LED constant-current segment driver. Each port
configured as an LED segment driver behaves as a
digitally controlled constant-current sink, with 16 equal
current steps from 1.5mA to 24mA. The LED drivers are
suitable for both discrete LEDs and CA numeric and
alphanumeric LED digits.
Each port configured as a general-purpose I/O (GPIO)
can be either a push-pull logic output capable of sink-
ing 10mA and sourcing 4.5mA, or a Schmitt logic input
with optional internal pullup. Seven ports feature config-
urable transition detection logic, which generates an
interrupt upon change of port logic level. The MAX6956
is controlled through an I²C-compatible 2-wire serial
interface, and uses four-level logic to allow 16 I²C
addresses from only 2 select pins.
The MAX6956AAX and MAX6956ATL have 28 ports
and are available in 36-pin SSOP and 40-pin thin QFN
packages, respectively. The MAX6956AAI and
MAX6956ANI have 20 ports and are available in 28-pin
SSOP and 28-pin DIP packages, respectively.
For an SPI-interfaced version, refer to the MAX6957
data sheet. For a lower cost pin-compatible port
expander without the constant-current LED drive capa-
bility, refer to the MAX7300 data sheet.
Features
o 400kbps I²C-Compatible Serial Interface
o 2.5V to 5.5V Operation
o -40°C to +125°C Temperature Range
o 20 or 28 I/O Ports, Each Configurable as
Constant-Current LED Driver
Push-Pull Logic Output
Schmitt Logic Input
Schmitt Logic Input with Internal Pullup
o 11µA (max) Shutdown Current
o 16-Step Individually Programmable Current
Control for Each LED
o Logic Transition Detection for Seven I/O Ports
Ordering Information
PART
TEMP RANGE
MAX6956ANI
-40°C to +125°C
MAX6956AAI
-40°C to +125°C
MAX6956AAX
-40°C to +125°C
MAX6956ATL
-40°C to +125°C
*EP = Exposed pad.
PIN-PACKAGE
28 DIP
28 SSOP
36 SSOP
40 Thin QFN-EP*
Pin Configurations
Set-Top Boxes
Panel Meters
White Goods
Automotive
Applications
Bar Graph Displays
Industrial Controllers
System Monitoring
Typical Operating Circuit appears at end of data sheet.
TOP VIEW
ISET 1
GND 2
GND 3
AD0 4
P12 5
P13 6
P14 7
P15 8
P16 9
P17 10
P18 11
P19 12
P20 13
P21 14
MAX6956
28 V+
27 AD1
26 SCL
25 SDA
24 P31
23 P30
22 P29
21 P28
20 P27
19 P26
18 P25
17 P24
16 P23
15 P22
SSOP/DIP
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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.