19-3057; Rev 3; 4/05
KIT
ATION
EVALU
E
BL
AVAILA
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
General Description
The MAX7312 2-wire-interfaced expander provides 16-bit
parallel input/output (I/O) port expansion in SMBus™ and
I
2
C applications. The MAX7312 consists of input port
registers, output port registers, polarity inversion regis-
ters, configuration registers, a bus timeout register, and
an I
2
C-compatible serial interface logic, compatible with
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
INT
output, SDA, SCL, and the slave address inputs
AD0-2 remain high impedance in power-down (V
t
= 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.
Features
♦
400kbps I
2
C-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
MAX7312
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
PKG
CODE
—
—
T2444-4
—
MAX7312AWG -40°C to +125°C 24 Wide SO
MAX7312AAG
MAX7312ATG
-40°C to +125°C 24 SSOP
-40°C to +125°C
24 Thin QFN
(4mm x 4mm)
Applications
Servers/Blades
RAID Systems
Medical Equipment
Instrumentation and Test Measurement
Networking
MAX7312AUG -40°C to +125°C 24 TSSOP
SMBus is a trademark of Intel Corp.
I,
Ia
l-
ne
I.
Pin Configurations
TOP VIEW
INT 1
AD1 2
AD2 3
I/O0 4
I/O1 5
I/O2 6
I/O3 7
I/O4 8
I/O5 9
I/O6 10
I/O7 11
GND 12
I/O15
I/O13
I/O12
14
23 SDA
22 SCL
21 AD0
SCL 19
SDA 20
V+ 21
INT 22
AD1 23
AD2 24
18
17
16
I/O14
15
13
12 I/O10
11 I/O9
10 I/O8
MAX7312
20 I/O15
19 I/O14
18 I/O13
17 I/O12
16 I/O11
MAX7312ATG
I/O11
AD0
24 V+
9
8
7
GND
I/O7
I/O6
1
2
3
4
5
6
I/O0
I/O1
I/O2
I/O3
I/O4
14 I/O9
13 I/O8
THIN QFN
TSSOP/SSOP/SO
________________________________________________________________
Maxim Integrated Products
I/O5
15 I/O10
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.
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
MAX7312
ABSOLUTE MAXIMUM RATINGS
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
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.
DC ELECTRICAL CHARACTERISTICS
(V+ = 2V to 5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage
Supply Current
SYMBOL
V
I
+
CONDITIONS
V
+
= 2V
MIN
2
TYP
23
43
80
2.3
2.9
3.8
1.4
MAX
5.5
35
60
120
11
12
15.5
1.7
0.3 x V
+
UNITS
V
µA
+
All I/Os unloaded,
f
SCL
= 400kHz
All I/Os unloaded,
f
SCL
= 0
V = 3.3V
V = 5.5V
V
+
= 2V
V = 3.3V
V
+
= 5.5V
+
+
+
Standby Current
Power-On Reset Voltage
SCL, SDA
Input Voltage Low
Input Voltage High
Low-Level Output Voltage
Leakage Current
Input Capacitance
I/O_
Input Voltage Low
Input Voltage High
Input Leakage Current
Low-Level Output Current
I
STBY
V
POR
V
IL
V
IH
V
OL
I
L
µA
V
V
V
V
µA
pF
0.7 x V
I
SINK
= 6mA
-1
+
0.4
+1
10
V
IL
V
IH
T
A
= -40°C to +85°C
V
+
= 2V, V
OL
= 0.5V
I
SINK
V = 3.3V, V
OL
= 0.5V
V
+
= 5V, V
OL
= 0.5V
V
+
= 3.3V, V
OH
= 2.4V
V = 5V, V
OH
= 4.5V
+
+
0.8
1.8
-1
8.5
17
29
17
32
43
41
31
0.3 x V
+
0.7 x V
+
V
V
µA
mA
+1
High Output Current
AD0, AD1, AD2
Input Voltage Low
Input Voltage High
I
SOURCE
mA
V
IL
V
IH
V
V
2
_______________________________________________________________________________________
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
DC ELECTRICAL CHARACTERISTICS (continued)
(V+ = 2V to 5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Leakage Current
Input Capacitance
INT
Low-Level Output Current
I
OL
V
OL
= 0.4V
6
mA
SYMBOL
CONDITIONS
MIN
-1
4
TYP
MAX
+1
UNITS
µA
pF
MAX7312
AC ELECTRICAL CHARACTERISTICS
(V+ = 2V to 5.5V, T
A
= -40°C to +125°C, unless otherwise noted.) (Note 1)
PARAMETER
SCL Clock Frequency
Bus Timeout
Bus Free Time Between STOP
and START Conditions
Hold Time (Repeated) START
Condition
Repeated START Condition
Setup Time
STOP Condition Setup Time
Data Hold Time
Data Setup Time
SCL Low Period
SCL High Period
SDA Fall Time
Pulse Width of Spike Suppressed
PORT TIMING
Output Data Valid
Input Data Setup Time
Input Data Hold Time
INTERRUPT TIMING
Interrupt Valid
Interrupt Reset
t
IV
t
IR
Figure 9
Figure 9
30.5
2
µs
µs
t
PV
Figure 7
27
0
3
µs
µs
µs
SYMBOL
f
SCL
t
TIMEOUT
t
BUF
t
HD,STA
t
SU,STA
t
SU,STO
t
HD,DAT
t
SU,DAT
t
LOW
t
HIGH
t
F
t
SP
Figure 2
Figure 2
Figure 2
Figure 2
Figure 2 (Note 3)
Figure 2
Figure 2
Figure 2
Figure 2 (Notes 4, 5)
(Note 6)
V+ < 3.3V
V+
≥
3.3V
50
100
1.3
0.7
500
250
(Note 2)
29
1.3
0.6
0.6
0.6
0.9
CONDITIONS
MIN
TYP
MAX
400
61
UNITS
kHz
ms
µs
µs
µs
µs
µs
ns
µs
µs
ns
ns
Note 1:
All parameters are 100% production tested at T
A
= +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 t
F
is
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.
_______________________________________________________________________________________
3
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
MAX7312
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX7312 toc02
SUPPLY CURRENT
vs. TEMPERATURE
MAX7312 toc01
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
9
8
SUPPLY CURRENT (μA)
7
6
5
4
3
2
1
0
V
+
= 2V
V
+
= 3.3V
SCL = V
+
ALL I/Os UNLOADED
V
+
= 5V
100
90
80
SUPPLY CURRENT (μA)
70
60
50
40
30
20
10
0
-50
-25
0
25
50
75
100
125
2.0
2.5
90
80
SUPPLY CURRENT (μA)
70
60
50
40
30
20
10
0
-50
f
SCL
= 400kHz
ALL I/Os UNLOADED
V
+
= 5V
f
SCL
= 400kHz
ALL I/Os UNLOADED
V
+
= 3.3V
V = 2V
+
-25
0
25
50
75
100
125
3.0
3.5
4.0
4.5
5.0
5.5
TEMPERATURE (°C)
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
I/O SINK CURRENT
vs. OUTPUT LOW VOLTAGE
24
22
20
18
16
I
SINK
(mA)
I
SINK
(mA)
14
12
10
8
6
4
2
0
0
0.1
0.2
0.3
V
OL
(V)
T
A
= +25°C
V
+
= 2V
T
A
= -40°C
MAX7312 toc04
I/O SINK CURRENT
vs. OUTPUT LOW VOLTAGE
MAX7312 toc05
I/O SINK CURRENT
vs. OUTPUT LOW VOLTAGE
V
+
= 5V
T
A
= -40°C
45
40
35
T
A
= +25°C
MAX7312 toc06
50
45
40
35
V
+
= 3.3V
T
A
= -40°C
50
T
A
= +25°C
I
SINK
(mA)
30
25
20
15
10
5
0
30
25
20
15
10
5
0
T
A
= +125°C
T
A
= +125°C
T
A
= +125°C
0.4
0.5
0.6
0
0.1
0.2
0.3
V
OL
(V)
0.4
0.5
0.6
0
0.1
0.2
0.3
0.4
0.5
V
OL
(V)
I/O OUTPUT LOW VOLTAGE
vs. TEMPERATURE
MAX7312 toc07
I/O SOURCE CURRENT
vs. OUTPUT HIGH VOLTAGE
MAX7312 toc08
I/O SOURCE CURRENT
vs. OUTPUT HIGH VOLTAGE
V
+
= 3.3V
T
A
= -40°C
45
40
35
I
SOURCE
(mA)
30
25
20
15
10
5
T
A
= +125°C
T
A
= +25°C
MAX7312 toc09
400
350
300
V
OL
(mV)
250
200
150
100
50
0
-50
-25
0
25
50
75
100
V
+
= 2V, I
SINK
= 1mA
V
+
= 5V, I
SINK
= 1mA
25
V
+
= 2V
T
A
= -40°C
T
A
= +25°C
50
V
+
= 5V, I
SINK
= 10mA
20
I
SOURCE
(mA)
15
V
+
= 2V, I
SINK
= 10mA
10
T
A
= +125°C
5
0
125
0
0.1
0.2
0.3
V
+
- V
0.4
OH
(V)
0
0.5
0.6
0.7
0
0.1
0.2
0.3
V
+
- V
0.4
OH
(V)
0.5
0.6
0.7
TEMPERATURE (°C)
4
_______________________________________________________________________________________
MAX7312 toc03
100
2-Wire-Interfaced 16-Bit I/O Port Expander
with Interrupt and Hot-Insertion Protection
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
I/O SOURCE CURRENT
vs. OUTPUT HIGH VOLTAGE
MAX7312 toc10
MAX7312
I/O HIGH VOLTAGE vs. TEMPERATURE
MAX7312 toc11
50
45
40
35
I
SOURCE
(mA)
30
25
20
15
10
5
0
0
V
+
= 5V
T
A
= -40°C
500
400
V
+
= 2V, I
SOURCE
= 10mA
V
+
- V
OH
(V)
T
A
= +25°C
300
200
T
A
= +125°C
100
V
+
= 5V, I
SOURCE
= 10mA
0
0.1
0.2
0.3
V
+
- V
OH
(V)
0.4
0.5
0.6
-50
-25
0
25
50
75
100
125
TEMPERATURE (°C)
Pin Description
PIN
TSSOP/
SSOP/SO
1
2
3
4–11
12
13–20
21
22
23
24
—
THIN
QFN
22
23
24
1–8
9
10–17
18
19
20
21
PAD
NAME
INT
AD1
AD2
I/O0–I/O7
GND
AD0
SCL
SDA
V
+
FUNCTION
Interrupt Output (Open Drain)
Address Input 1
Address Input 2
Input/Output Port 1
Supply Ground
Address Input 0
Serial Clock Line
Serial Data Line
Supply Voltage. Bypass with a 0.047µF capacitor to GND.
Exposed Pad on Package Underside. Connect to GND.
I/O8–I/O15 Input/Output Port 2
Exposed
pad
_______________________________________________________________________________________
5
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