19-2747; Rev 4; 4/05
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
General Description
Features
♦ 400kbps I2C-Compatible Serial Interface
The MAX7311 2-wire-interfaced expander provides 16-bit
parallel input/output (I/O) port expansion for SMBus™
and I2C™ applications. The MAX7311 consists of input
port registers, output port registers, polarity inversion reg-
isters, configuration registers, a bus timeout register, and
an I2C-compatible serial interface logic compatible with
SMBus. The system master can invert the MAX7311 input
data by writing to the active-high polarity inversion regis-
ter. The system master can enable or disable bus timeout
by writing to the bus timeout register.
♦ 2V to 5.5V Operation
♦ 5V Overvoltage Tolerant I/Os
♦ Supports Hot Insertion
♦ 16 I/O Pins that Default to Inputs on Power-Up
♦ 100kΩ Pullup on Each I/O
♦ Open-Drain Interrupt Output (INT)
♦ Bus Timeout for Lock-Up-Free Operation
♦ Noise Filter on SCL / SDA Inputs
♦ 64 Slave ID Addresses Available
♦ Low Standby Current (2.9µA typ)
♦ Polarity Inversion
Any of the 16 I/O ports can be configured as an input or
output. A power-on reset (POR) initializes the 16 I/Os
as inputs. Three address select pins configure one of
64 slave ID addresses.
The MAX7311 supports hot insertion. All port pins, the
INT output, SDA, SCL and the slave address inputs
AD0–2 remain high impedance in power down (V+ =
0V) with up to 6V asserted upon them.
♦ 4mm ✕ 4mm, 0.8mm Thin QFN Package
♦ -40°C to +125°C Operation
The MAX7311 is available in 24-pin SO, SSOP, TSSOP,
and thin QFN packages and is specified over the -40°C
to +125°C automotive temperature range.
Ordering Information
For applications requiring I/Os without pullup resistors,
refer to the MAX7312 data sheet.
PKG
CODE
PART
TEMP RANGE PIN-PACKAGE
Applications
MAX7311AWG -40°C to +125°C 24 Wide SO
MAX7311AAG -40°C to +125°C 24 SSOP
—
—
Servers
RAID Systems
24 Thin QFN
MAX7311ATG -40°C to +125°C
(4mm ✕ 4mm)
T2444-4
—
Industrial Control
Medical Equipment
PLCs
MAX7311AUG -40°C to +125°C 24 TSSOP
SMBus is a trademark of Intel Corp.
Purchase of I2C components of Maxim Integrated Products, Inc.
or one of its sublicensed Associated Companies, conveys a
license under the Phillips I2C Patent Rights to use these compo-
nents in an I2C system, provided that the system conforms to the
I2C Standard Specification as defined by Phillips.
Instrumentation and Test Measurement
Pin Configurations
TOP VIEW
18 17 16 15 14 13
+
24 V
INT
AD1
AD2
I/O0
I/O1
I/O2
I/O3
I/O4
I/O5
1
2
3
4
5
6
7
8
9
SCL 19
SDA 20
V+ 21
12 I/O10
11 I/O9
10 I/O8
23 SDA
22 SCL
21 AD0
20 I/O15
19 I/O14
18 I/O13
17 I/O12
16 I/O11
15 I/O10
14 I/O9
13 I/O8
MAX7311ATG
INT
AD1
AD2
GND
I/O7
I/O6
22
23
24
9
8
7
MAX7311
1
2
3
4
5
6
THIN QFN
I/O6 10
I/O7 11
GND 12
TSSOP/SSOP/SO
________________________________________________________________ Maxim Integrated Products
1
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.