MAX7321_14 Datasheet, PDF (1/15 Pages) Maxim Integrated Products – I2C Port Expander with 8 Open-Drain I/Os

MAX7321
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
protected to +6V independent of supply voltage.
All I/O ports configured as inputs are continuously
monitored for state changes (transition detection). State
changes are indicated by the open-drain INT output.
The interrupt is latched, allowing detection of transient
changes. When the MAX7321 is subsequently 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 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 state for the I/O ports,
and enables or disables internal 40kΩ pullups in groups
of four ports.
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 TQFN
packages, and is specified over the automotive temper-
ature range (-40°C to +125°C).
Applications
●● Cell Phones
●● SAN/NAS
●● Servers
●● Notebooks
●● Satellite Radio
Pin Configurations
+
AD0 1
RST 2
AD2 3
P0 4
MAX7321
P1 5
P2 6
P3 7
GND 8
QSOP
16 V+
15 SDA
14 SCL
13 INT
12 P7
11 P6
10 P5
9 P4
Features
●● 400kHz 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 States
●● 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) Standby Current
●● -40°C to +125°C Operating Temperature
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
MAX7321AEE+ -40°C to +125°C 16 QSOP
MAX7321ATE+ -40°C to +125°C 16 TQFN-EP*
TOP
MARK
—
ADC
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
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
—
Pin Configurations are continued at end of data sheet.
Typical Application Circuit and Functional Diagram appear
at end of data sheet.
19-3738; Rev 4; 7/14