MAXIM MAX7312 User Manual

19-3057; Rev 3; 4/05

with Interrupt and Hot-Insertion Protection

EVALUATION KIT

AVAILABLE

2-Wire-Interfaced 16-Bit I/O Port Expander

General Description

The MAX7312 2-wire-interfaced expander provides 16-bit
parallel input/output (I/O) port expansion in SMBus™ and

2

C applications. The MAX7312 consists of input port

I
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

MAX7312AWG -40°C to +125°C 24 Wide SO —

MAX7312AAG -40°C to +125°C 24 SSOP —

MAX7312ATG -40°C to +125°C

24 Thin QFN
(4mm x 4mm)

MAX7312AUG -40°C to +125°C 24 TSSOP —

SMBus is a trademark of Intel Corp.

I,
Ia
l­ne
I.

CODE

T2444-4

MAX7312

PKG

Pin Configurations

TOP VIEW

1

INT

2

AD1

3

AD2

4

5

I/O1

6

I/O2

7

I/O3

8

9

I/O5

10

I/O6

11

I/O7

12

TSSOP/SSOP/SO

MAX7312

________________________________________________________________ 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.

+

24

V

23

SDA

22

SCL

21

AD0I/O0

20

I/O15

19

I/O14

18

I/O13

17

I/O12I/O4

16

I/O11

15

I/O10

14

I/O9

13

I/O8GND

SCL

SDA

INT

AD1

AD2

AD0

18 17 16 15 14 13

19

20

21

V+

22

23

24

12 3456

I/O0

I/O13

I/O15

I/O14

MAX7312ATG

I/O1

I/O2

I/O3

THIN QFN

I/O12

I/O4

I/O11

I/O5

12

I/O10

11

I/O9

10

I/O8

GND

9

I/O7

8

I/O6

7

MAX7312

2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(V+= 2V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at V+= 3.3V, TA= +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

V+to GND ................................................................-0.3V to +6V

I/O0–I/O15 as Inputs ....................................(GND - 0.3V) to +6V

SCL, SDA, AD0, AD1, AD2, INT...................(GND - 0.3V) to +6V

Maximum V

+

Current ......................................................+250mA

Maximum GND Current ...................................................-250mA

DC Input Current on I/O0–I/O15 .......................................±20mA

DC Output Current on I/O0–I/O15 ....................................±80mA

Continuous Power Dissipation (T

A

= +70°C)

24-Pin Wide SO (derate 11.8mW/°C above +70°C) ....941mW

24-Pin SSOP (derate 8.0mW/°C above +70°C) ...........640mW

24-Pin TSSOP (derate 12.2mW/°C above +70°C) .......975mW

24-Pin Thin QFN (derate 20.8mW/°C above +70°C) .1668mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Supply Voltage V

Power-On Reset Voltage V

SCL, SDA

Input Voltage Low V

Input Voltage High

Low-Level Output Voltage V

Leakage Current I

Input Capacitance 10 pF

I/O_

Input Voltage Low V

Input Voltage High V

Input Leakage Current TA = -40°C to +85°C -1 +1 µA

Low-Level Output Current I

High Output Current I

AD0, AD1, AD2

Input Voltage Low V

Input Voltage High V

PARAMETER SYM B O L CONDITIONS MIN TYP MAX UNITS

+

+

STBY

POR

IL

V

IH

OL

L

IL

IH

SINK

SOURCE

IL

IH

All I/Os unloaded,

= 400kHz

f

SCL

All I/Os unloaded,

= 0

f

SCL

I

= 6mA 0.4 V

SINK

V+ = 2V, VOL = 0.5V 8.5 17

V+ = 3.3V, VOL = 0.5V 17 32

V+ = 5V, VOL = 0.5V 43

V+ = 3.3V, VOH = 2.4V 29 41

V+ = 5V, VOH = 4.5V 31

V+ = 2V 23 35

V+ = 3.3V 43 60Supply Current I

+

= 5.5V 80 120

V

V+ = 2V 2.3 11

V+ = 3.3V 2.9 12Standby Current I

+

= 5.5V 3.8 15.5

V

2 5.5 V

1.4 1.7 V

+

0.3 x V

+

0.7 x V

-1 +1 µA

0.8 V

1.8 V

+

0.3 x V

0.7 x V

+

µA

µA

V

V

mA

mA

V

V

MAX7312

2-Wire-Interfaced 16-Bit I/O Port Expander

with Interrupt and Hot-Insertion Protection

_______________________________________________________________________________________ 3

Note 1: All parameters are 100% production tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Minimum SCL clock frequency is limited by the MAX7312 bus timeout feature, which resets the serial bus interface if either

SDA or SCL is held low for a minimum of 25ms. Disable bus timeout feature for DC operation.

Note 3: A master device must internally provide a hold time of at least 300ns for the SDA signal (referred to the V

IL

of the SCL

signal) in order to bridge the undefined region SCL’s falling edge.

Note 4: C

B

= total capacitance of one bus line in pF.

Note 5: The maximum t

F

for the SDA and SCL bus lines is specified at 300ns. The maximum fall time for the SDA output stage tFis
specified at 250ns. This allows series protection resistors to be connected between the SDA and SCL pins and the
SDA/SCL bus lines without exceeding the maximum specified t

F

.

Note 6: Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.

DC ELECTRICAL CHARACTERISTICS (continued)

(V+= 2V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at V+= 3.3V, TA= +25°C.) (Note 1)

AC ELECTRICAL CHARACTERISTICS

(V+= 2V to 5.5V, TA= -40°C to +125°C, unless otherwise noted.) (Note 1)

Leakage Current -1 +1 µA

Input Capacitance 4pF

INT

Low-Level Output Current I

PARAMETER SYM B O L CONDITIONS MIN TYP MAX UNITS

V

OL

= 0.4V 6 mA

OL

SCL Clock Frequency f

Bus Timeout t

Bus Free Time Between STOP
and START Conditions

Hold Time (Repeated) START
Condition

Repeated START Condition
Setup Time

STOP Condition Setup Time t

Data Hold Time t

Data Setup Time t

SCL Low Period t

SCL High Period t

SDA Fall Time t

Pulse Width of Spike Suppressed t

PORT TIMING

Output Data Valid t

Input Data Setup Time 27 µs

Input Data Hold Time 0µs

INTERRUPT TIMING

Interrupt Valid t

Interrupt Reset t

PARAMETER SYM B O L CONDITIONS MIN TYP MAX UNITS

SCL

TIMEOUT

t

BUF

t

HD,STA

t

SU,STA

SU,STO

HD,DAT

SU,DAT

LOW

HIGH

SP

PV

(Note 2) 400 kHz

29 61 ms

Figure 2 1.3 µs

Figure 2 0.6 µs

Figure 2 0.6 µs

Figure 2 0.6 µs

Figure 2 (Note 3) 0.9 µs

Figure 2 100 ns

Figure 2 1.3 µs

Figure 2 0.7 µs

Figure 2 (Notes 4, 5)

F

(Note 6) 50 ns

Figure 7 3 µs

Figure 9 30.5 µs

IV

Figure 9 2 µs

IR

V+ < 3.3V 500

V+ ≥ 3.3V 250

ns

MAX7312

2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection

4 _______________________________________________________________________________________

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

SUPPLY CURRENT

vs. TEMPERATURE

MAX7312 toc01

TEMPERATURE (°C)

SUPPLY CURRENT (μA)

1007525 500-25

10

20

30

40

50

60

70

80

90

100

0

-50 125

f

SCL

= 400kHz

ALL I/Os UNLOADED

V+ = 3.3V

V+ = 5V

V+ = 2V

STANDBY SUPPLY CURRENT

vs. TEMPERATURE

MAX7312 toc02

TEMPERATURE (°C)

SUPPLY CURRENT (μA)

1007525 500-25

1

2

3

4

5

6

7

8

9

0

-50 125

SCL = V

+

ALL I/Os UNLOADED

V+ = 3.3V

V+ = 5V

V+ = 2V

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7312 toc03

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (μA)

5.04.53.5 4.03.02.5

10

20

30

40

50

60

70

80

90

100

0

2.0 5.5

f

SCL

= 400kHz

ALL I/Os UNLOADED

I/O SINK CURRENT

vs. OUTPUT LOW VOLTAGE

MAX7312 toc04

VOL (V)

I

SINK

(mA)

0.50.40.30.20.1

2

4

6

8

10

12

14

16

18

20

22

24

0

00.6

V+ = 2V

TA = +125°C

TA = +25°C

TA = -40°C

I/O SINK CURRENT

vs. OUTPUT LOW VOLTAGE

MAX7312 toc05

VOL (V)

I

SINK

(mA)

0.50.40.30.20.1

5

10

15

20

25

30

35

40

45

50

0

0 0.6

V+ = 3.3V

TA = +125°C

TA = -40°C

TA = +25°C

I/O SINK CURRENT

vs. OUTPUT LOW VOLTAGE

MAX7312 toc06

VOL (V)

I

SINK

(mA)

0.40.30.20.1

5

10

15

20

25

30

35

40

45

50

0

00.5

V+ = 5V

TA = +125°C

TA = -40°C

TA = +25°C

I/O OUTPUT LOW VOLTAGE

vs. TEMPERATURE

MAX7312 toc07

TEMPERATURE (°C)

V

OL

(mV)

10075-25 0 25 50

50

100

150

200

250

300

350

400

0

-50 125

V+ = 5V, I

SINK

= 10mA

V+ = 2V, I

SINK

= 10mA

V+ = 2V, I

SINK

= 1mA

V+ = 5V, I

SINK

= 1mA

I/O SOURCE CURRENT

vs. OUTPUT HIGH VOLTAGE

MAX7312 toc08

V+ - VOH (V)

I

SOURCE

(mA)

0.60.50.40.30.20.1

5

10

15

20

25

0

0 0.7

V+ = 2V

TA = +125°C

TA = +25°C

TA = -40°C

I/O SOURCE CURRENT

vs. OUTPUT HIGH VOLTAGE

MAX7312 toc09

V+ - VOH (V)

I

SOURCE

(mA)

0.60.50.3 0.40.20.1

5

10

15

20

25

30

35

40

45

50

0

00.7

V+ = 3.3V

TA = +125°C

TA = +25°C

TA = -40°C

MAX7312

2-Wire-Interfaced 16-Bit I/O Port Expander

with Interrupt and Hot-Insertion Protection

_______________________________________________________________________________________ 5

Pin Description

Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

I/O SOURCE CURRENT

vs. OUTPUT HIGH VOLTAGE

MAX7312 toc10

V+ - VOH (V)

I

SOURCE

(mA)

0.60.50.3 0.40.20.1

5

10

15

20

25

30

35

40

45

50

0

0

V+ = 5V

TA = +125°C

TA = +25°C

TA = -40°C

I/O HIGH VOLTAGE vs. TEMPERATURE

MAX7312 toc11

TEMPERATURE (°C)

V

+

- V

OH

(V)

1007550250-25

100

200

300

400

500

0

-50 125

V+ = 5V, I

SOURCE

= 10mA

V+ = 2V, I

SOURCE

= 10mA

PIN

TSSOP/

SSOP/SO

THIN

QFN

122INT Interrupt Output (Open Drain)

2 23 AD1 Address Input 1

3 24 AD2 Address Input 2

4–11 1–8 I/O0–I/O7 Input/Output Port 1

12 9 GND Supply Ground

13–20 10–17 I/O8–I/O15 Input/Output Port 2

21 18 AD0 Address Input 0

22 19 SCL Serial Clock Line

23 20 SDA Serial Data Line

24 21 V

— PAD

NAME FUNCTION

+

Supply Voltage. Bypass with a 0.047µF capacitor to GND.

Exposed

pad

Exposed Pad on Package Underside. Connect to GND.