19-3057; Rev 3; 4/05
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
The MAX7312 2-wire-interfaced expander provides 16-bit
parallel input/output (I/O) port expansion in SMBus™ and
I2C™ applications. The MAX7312 consists of input port
registers, output port registers, polarity inversion registers, configuration registers, a bus timeout register, and
an I2C-compatible serial interface logic, compatible with
SMBus. The system master can invert the MAX7312 input
data by writing to the active-high polarity inversion register. The system master can enable or disable bus timeout
by writing to the bus timeout register.
Any of the 16 I/O ports can be configured as an input or
an output. A power-on reset (POR) initializes the 16 I/Os
as inputs. Three address select pins configure the part
to one of 64 slave ID addresses.
The MAX7312 supports hot insertion. All port pins, the
INT output, SDA, SCL, and the slave address inputs
AD0-2 remain high impedance in power-down (Vt = 0V)
up to 6V.
The MAX7312 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.
For applications requiring I/Os with integrated 100kΩ
pullup resistors, refer to the MAX7311 data sheet.
Applications
Servers/Blades
RAID Systems
Medical Equipment
Instrumentation and Test Measurement
Networking
Features
♦ 400kbps I2C-Compatible Serial Interface
♦ 2V to 5.5V Operation
♦ 5V Overvoltage Tolerant I/Os
♦
♦
♦
♦
♦
Supports Hot Insertion
16 I/O Pins that Default to Inputs on Power-Up
Open-Drain Interrupt Output (INT)
Bus Timeout for Lock-Up-Free Operation
Noise Filter on SCL/SDA Inputs
♦
♦
♦
♦
♦
64 User-Selectable Slave ID Addresses
Low Standby Current (2.9µA typ)
Polarity Inversion
4mm ✕ 4mm, 0.8mm Thin QFN Package
-40°C to +125°C Operation
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
PKG
CODE
MAX7312AWG -40°C to +125°C 24 Wide SO
—
MAX7312AAG
-40°C to +125°C 24 SSOP
—
MAX7312ATG
24 Thin QFN
-40°C to +125°C
(4mm x 4mm)
T2444-4
MAX7312AUG -40°C to +125°C 24 TSSOP
—
SMBus is a trademark of Intel Corp.
I2C Purchase of I2C components of Maxim Integrated Products,
Inc., or one of its Sublicense Associate Companies conveys a
license under the Philips I2C Patent Rights to use these components in an I2C system provided that the system conforms to the
I2C Standard Specifications as defined by Philips.
21 AD0
20 I/O15
I/O2 6
19 I/O14
I/O3 7
18 I/O13
13
SCL 19
12 I/O10
SDA 20
11 I/O9
V+ 21
10 I/O8
MAX7312ATG
INT 22
9
GND
AD1 23
8
I/O7
AD2 24
7
I/O6
1
I/O6 10
15 I/O10
I/O7 11
14 I/O9
GND 12
2
3
4
5
6
I/O5
16 I/O11
I/O4
I/O5 9
17 I/O12
14
I/O3
I/O4 8
15
I/O2
MAX7312
16
I/O1
I/O1 5
17
I/O11
I/O0 4
18
I/O13
22 SCL
I/O12
23 SDA
AD2 3
I/O15
24 V+
AD0
INT 1
AD1 2
I/O0
TOP VIEW
I/O14
Pin Configurations
13 I/O8
THIN QFN
TSSOP/SSOP/SO
________________________________________________________________ Maxim Integrated Products
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.
1
MAX7312
General Description
