Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - I/O extensions POR I²C 400 kHz TQFN 16 EP

Pin Configurations are continued at end of data sheet.

Typical Application Circuit and Functional Diagram appear

at end of data sheet.

● Cell Phones

● SAN/NAS

● Servers

● Notebooks

● Satellite Radio

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

C communication to or from the MAX7321.

The MAX7321 uses two address inputs with four-level

logic to allow 16 I

C 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).

Features

● 400kHz I

C 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

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

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 —

PART TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX7321AEE+ -40°C to +125°C 16 QSOP —

MAX7321ATE+ -40°C to +125°C 16 TQFN-EP* ADC

AD0

V+

SDA

SCL

INT

MAX7321

QSOP

RST

AD2

GND

MAX7321 I

C Port Expander with 8 Open-Drain I/Os

19-3738; Rev 4; 7/14

Selector Guide

Ordering Information

Pin Congurations

Applications

Summary of content (15 pages)

PAGE 1
I2C Port Expander with 8 Open-Drain I/Os MAX7321 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.
PAGE 2
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Absolute Maximum Ratings (All voltages referenced to GND.) Supply Voltage V+....................................................-0.3V to +6V SCL, SDA, AD0, AD2, RST, INT, P0–P7................-0.3V to +6V P0–P7 Sink Current........................................................ 25mA SDA Sink Current............................................................... 10mA INT Sink Current.................................................................
PAGE 3
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Port and Interrupt INT Timing Characteristics (V+ = +1.71V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at V+ = +3.3V, TA = +25°C.
PAGE 4
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) 1.4 1.2 V+ = +5.0V 1.0 V+ = +2.5V 0.8 V+ = +3.3V 0.6 0.4 V+ = +1.71V 0.2 0 V+ = +5.0V 50 40 V+ = +3.3V 30 20 V+ = +2.5V 10 -40 -25 -10 5 20 35 50 65 80 95 110 125 0 0.40 0.35 0.30 V+ = +5.0V ISINK = 20mA 0.25 0.20 0.15 V+ = +2.5V V+ = +3.3V ISINK = 10mA ISINK = 15mA 0.10 0.05 V+ = +1.
PAGE 5
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Detailed Description Functional Overview MAX7319–MAX7329 Family Comparison The MAX7319–MAX7323 family consists of five pincompatible, eight-port expanders. Each version is optimized for different applications. The MAX7328 and MAX7329 are industry standard parts. The MAX7324–MAX7327 family consists of four pincompatible, 16-port expanders that integrate the functions of the MAX7320 and one of either the MAX7319, MAX7321, MAX7322, or MAX7323.
PAGE 6
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Table 1. MAX7319–MAX7329 Family Comparison (continued) PART MAX7323 I2C INPUT SLAVE INPUTS INTERRUPT ADDRESS MASK 110xxxx Up to 4 — OPENDRAIN OUTPUTS Up to 4 PUSHPULL OUTPUTS 4 APPLICATION 4 I/O, 4 output-only versions: 4 open-drain I/O ports with latching transition detection interrupt and selectable pullups. 4 push-pull outputs with selectable power-up default levels.
PAGE 7
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Table 2.
PAGE 8
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Table 3.
PAGE 9
I2C Port Expander with 8 Open-Drain I/Os MAX7321 SDA tSU,STA tSU,DAT tLOW tHD,DAT tBUF tHD,STA tSU,STO tHIGH SCL tHD,STA tR tF START CONDITION REPEATED START CONDITION STOP CONDITION START CONDITION Figure 1. 2-Wire Serial Interface Timing Details Serial Interface Serial Addressing SDA The MAX7321 operates as a slave that sends and receives data through an I2C interface.
PAGE 10
MAX7321 I2C Port Expander with 8 Open-Drain I/Os Accessing the MAX7321 The MAX7321 is accessed through an I2C interface. The transition flags are cleared, and INT is deasserted each time the device acknowledges the I2C slave address. A single-byte read from the MAX7321 returns the status of the eight I/O ports. A 2-byte read returns first the status of the eight I/O ports (as for a single-byte read), followed by the transition flags.
PAGE 11
I2C Port Expander with 8 Open-Drain I/Os MAX7321 1 SDA 1 0 A2 A3 A1 A0 R/W ACK LSB MSB SCL Figure 5. Slave Address PORT I/O P6 P7 S 1 1 0 MAX7321 SLAVE ADDRESS 1 A R/W D7 P5 D6 P4 P3 DATA D5 D4 P1 P2 D3 D2 P0 D1 D0 N P PORT SNAPSHOT PORT SNAPSHOT SCL tPH PORT I/O tIV tPSU tIR INT OUTPUT tIP INT REMAINS HIGH UNTIL STOP CONDITION Figure 6.
PAGE 12
I2C Port Expander with 8 Open-Drain I/Os MAX7321 1 SCL 2 3 4 5 6 7 8 DATA TO PORT SLAVE ADDRESS SDA S 0 START CONDITION A DATA TO PORT DATA 1 A DATA 2 A R/W tPV INTERNAL WRITE TO PORT DATA OUT FROM PORT tPV DATA 1 VALID tPV DATA 2 VALID tPV S = START CONDITION SHADED = SLAVE TRANSMISSION P = STOP CONDITION N = NOT ACKNOWLEDGE Figure 8.
PAGE 13
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Functional Diagram AD0 P7 P6 P5 P4 P3 P2 P1 P0 AD2 SCL SDA RST INPUT I2 C CONTROL FILTER I/O PORTS INT POWERON RESET MAX7321 Driving LED Loads When driving LEDs, a resistor must be fitted in series with the LED to limit the LED current to no more than 20mA. Connect the LED cathode to the MAX7321 port, and the LED anode to V+ through the series currentlimiting resistor (RLED). Set the port output low to illuminate the LED.
PAGE 14
Typical Application Circuit 0.047µF SCL SCL SDA SDA RST RST INT INT P5 P4 P3 P2 I/O I/O I/O I/O P1 P0 GND P6 TOP VIEW P7 Pin Configurations (continued) 12 11 10 9 SDA 13 V+ 14 MAX7321 AD0 15 1 2 3 4 P2 RST 16 The MAX7321 clears data stored in the interrupt flag and deasserts the corresponding interrupt when an I2C master reads any I2C slave on the same bus.
PAGE 15
I2C Port Expander with 8 Open-Drain I/Os MAX7321 Revision History REVISION NUMBER REVISION DATE 0 7/05 Initial release 1 4/06 Updates to data sheet 2 7/13 Added the I2C Flag Clearing Deassertion Anomaly section 14 3 5/14 No /V OPNs; removed automotive reference from Applications section 1 7/14 Revised the Issue: I2C Flag Clearing Deassertion Anomaly section 14 4 PAGES CHANGED DESCRIPTION — 1–17 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629