19-3381; Rev 2; 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 MAX7318 2-wire-interfaced expander provides 16-
bit parallel input/output (I/O) port expansion for
SMBus™ and I2C™ applications. The MAX7318 con-
sists of input port registers, output port registers, polari-
ty inversion registers, configuration registers, a bus
timeout register, and an I2C-compatible serial interface
logic compatible with SMBus. The system master can
invert the MAX7318 input data by writing to the active-
high polarity inversion register.
♦ 2V to 5.5V Operation
♦ 5.5V 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)
♦ Noise Filter on SCL/SDA Inputs
♦ 64 Slave ID Addresses Available
♦ Low Standby Current (5.4µA 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 MAX7318 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 MAX7318 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 an SMBus timeout function,
refer to the MAX7311 data sheet.
PKG
PART
TEMP RANGE PIN-PACKAGE
Applications
CODE
MAX7318AWG -40°C to +125°C 24 Wide SO
MAX7318AAG -40°C to +125°C 24 SSOP
—
—
Servers
RAID Systems
Industrial Control
Medical Equipment
PLCs
24 Thin QFN
MAX7318ATG -40°C to +125°C
(4mm ✕ 4mm)
T2444-4
—
MAX7318AUG -40°C to +125°C 24 TSSOP
Instrumentation and Test Measurement
SMBus is a trademark of Intel Corp.
I2C is a trademark of Philips Corp.
Purchase of I2C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys a
license under the Philips 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 Philips.
Pin Configurations
TOP VIEW
18 17 16 15 14 13
INT
AD1
AD2
I/O0
I/O1
I/O2
I/O3
I/O4
I/O5
1
2
3
4
5
6
7
8
9
24 V+
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
MAX7318ATG
INT
AD1
AD2
GND
I/O7
I/O6
22
23
24
9
8
7
MAX7318
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.