19-3057; Rev 3; 4/05
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
General Description
Features
♦ 400kbps I C-Compatible Serial Interface
♦ 2V to 5.5V Operation
2
The MAX7312 2-wire-interfaced expander provides 16-bit
parallel input/output (I/O) port expansion in SMBus™ and
2
I C applications. The MAX7312 consists of input port
♦ 5V Overvoltage Tolerant I/Os
registers, output port registers, polarity inversion regis-
ters, configuration registers, a bus timeout register, and
♦ Supports Hot Insertion
2
an I C-compatible serial interface logic, compatible with
♦ 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
SMBus. The system master can invert the MAX7312 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.
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
♦ 4mm ✕ 4mm, 0.8mm Thin QFN Package
♦ -40°C to +125°C Operation
INT output, SDA, SCL, and the slave address inputs
AD0-2 remain high impedance in power-down (V = 0V)
t
up to 6V.
Ordering Information
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.
PKG
CODE
PART
TEMP RANGE PIN-PACKAGE
MAX7312AWG -40°C to +125°C 24 Wide SO
MAX7312AAG -40°C to +125°C 24 SSOP
—
—
For applications requiring I/Os with integrated 100kΩ
pullup resistors, refer to the MAX7311 data sheet.
24 Thin QFN
MAX7312ATG -40°C to +125°C
(4mm x 4mm)
T2444-4
—
Applications
Servers/Blades
MAX7312AUG -40°C to +125°C 24 TSSOP
RAID Systems
SMBus is a trademark of Intel Corp.
Medical Equipment
Instrumentation and Test Measurement
Networking
Pin Configurations
TOP VIEW
+
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
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
18 17 16 15 14 13
19
12
SCL
I/O10
SDA 20
11 I/O9
MAX7312
21
22
23
24
10
9
V+
I/O8
MAX7312ATG
INT
GND
AD1
AD2
I/O7
I/O6
8
7
1
2
3
4
5
6
I/O6 10
I/O7 11
GND 12
THIN QFN
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.