MAX7321 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – I2C Port Expander with 8 Open-Drain I/Os

19-3738; Rev 0; 7/05
I²C Port Expander with 8 Open-Drain I/Os
General Description
The MAX7321 2-wire serial-interfaced peripheral features
eight open-drain I/O ports with selectable internal pullups
and transition detection. Any port may be used as a logic
input or an open-drain output. Ports are overvoltage pro-
tected to +6V independent of supply voltage.
All I/O ports configured as inputs are continuously mon-
itored for state changes (transition detection). State
changes are indicated by the open-drain, +6V tolerant
INT output. The interrupt is latched, allowing detection
of transient changes. When the MAX7321 is subse-
quently accessed through the serial interface, any
pending interrupt is cleared.
The open-drain outputs are rated to sink 20mA and are
capable of driving LEDs.
The +6V tolerant RST input clears the serial interface,
terminating any I²C* communication to or from the
MAX7321.
The MAX7321 uses two address inputs with four-level
logic to allow 16 I²C slave addresses. The slave
address also determines the power-up logic level for
the I/O ports, and enables or disables internal 40kΩ
pullups in groups of four ports.
The MAX7321 supports hot insertion. All eight I/O ports,
the serial interface SDA, SCL, AD0, AD2, INT, and RST
remain high impedance in power-down (V+ = 0) with
up to +6V asserted on them.
The MAX7321 is one device in a family of pin-compatible
port expanders with a choice of input ports, open-drain
I/O ports, and push-pull output ports (see Table 1).
The MAX7321 is available in 16-pin QSOP and 16-pin
TQFN packages, and is specified over the automotive
temperature range (-40°C to +125°C).
Cell Phones
SAN/NAS
Servers
Applications
Notebooks
Satellite Radio
Automotive
Pin Configurations, Typical Application Circuit, and
Functional Diagram appear at end of data sheet.
*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 com-
ponents in an I²C system, provided that the system conforms
to the I²C Standard Specification as defined by Philips.
Features
♦ 400kHz, +6V Tolerant I²C Serial Interface
♦ +1.71V to +5.5V Operating Voltage
♦ 8 Open-Drain I/O Ports Rated to 20mA Sink Current
♦ I/O Ports Are Overvoltage Protected to +6V
♦ Any Port Can Be a Logic Input or an Open-Drain
Output
♦ Selectable I/O Port Power-Up Default Logic Levels
♦ Transient Changes Are Latched, Allowing Detection
Between Read Operations
♦ INT Output Alerts Change on Inputs
♦ AD0 and AD2 Inputs Select from 16 Slave
Addresses
♦ Low 0.6µA (typ), 1.5µA (max) Standby Current
♦ -40°C to +125°C Operating Temperature
Ordering Information
PART
TEMP PIN-
RANGE PACKAGE
TOP PKG
MARK CODE
MAX7321AEE
-40°C to
+125°C
16 QSOP
— E16-4
MAX7321ATE
-40°C to
+125°C
16 TQFN
3mm x 3mm
x 0.8mm
ADC T1633-4
-40°C to
MAX7321ASE* _+125°C 16 SO
—
—
MAX7321AUP* ^{-40°C to} 20 TSSOP
+125°C
—
—
MAX7321AAP* ^{-40°C to} 20 SSOP
+125°C
—
—
*Future product—contact factory for availability.
Selector Guide
PART
INPUTS
INTERRUPT
MASK
OPEN-
DRAIN
OUTPUTS
PUSH-PULL
OUTPUTS
MAX7319 8
Yes
—
—
MAX7320 —
—
—
8
MAX7321 Up to 8
—
Up to 8
—
MAX7322 4
Yes
—
4
MAX7323 Up to 4
—
Up to 4
4
MAX7328 Up to 8
—
Up to 8
—
MAX7329 Up to 8
—
Up to 8
—
________________________________________________________________ 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.