General Description
The MAX1608/MAX1609 provide remote input/output (I/O)
expansion through an SMBusTM 2-wire serial interface.
Each device has eight high-voltage open-drain outputs
that double as TTL-level logic inputs, providing continuous
bidirectional capabilities. The open-drain outputs tailor the
MAX1608/MAX1609 for use in load-switching and other
level-shifting applications as well as general-purpose I/O
applications.
Two complete sets of registers allow the device and its
outputs to be toggled between two states using the
SMBSUS input, without the inherent latency of reprogram-
ming outputs over the serial bus. The eight I/O lines are
continuously monitored and can be used as inputs. Each
line can generate asynchronous maskable interrupts on
the falling edge, the rising edge, or both edges.
For load-switching applications, the MAX1608 is designed
to drive N-channel MOSFETs, and its outputs are low
upon power-up; the MAX1609 is designed to drive P-
channel MOSFETs, and its I/Os are high impedance upon
power-up. Other features of both devices include thermal-
overload and output-overcurrent protection, ultra-low sup-
ply current, and a wide +2.7V to +5.5V supply range. The
MAX1608/MAX1609 are available in space-saving 16-pin
QSOP packages.
Applications
Parallel I/O Expansion
Power-Plane Switching
Notebook and Desktop Computers
Servers and Workstations
Notebook Docking Stations
Industrial Equipment
Features
o Serial-to-Parallel or Parallel-to-Serial Conversions
o 8 General-Purpose Digital I/O Pins
(withstand +28V)
o SMBus 2-Wire Serial Interface
o Supports SMBSUS Asynchronous Suspend
o 9 Pin-Selectable Slave Addresses
o Outputs High Impedance on Power-Up (MAX1609)
o Outputs Low on Power-Up (MAX1608)
o 2.5A Supply Current
o +2.7V to +5.5V Supply Range
o 16-Pin QSOP Package
MAX1608/MAX1609
Octal SMBus-to-Parallel I/O Expanders
________________________________________________________________ Maxim Integrated Products
1
19-1639; Rev 0; 1/00
PART
MAX1608EEE
MAX1609EEE
-40C to +85C
-40C to +85C
TEMP. RANGE
PIN-PACKAGE
16 QSOP
16 QSOP
Ordering Information
Typical Operating Circuits
MAX1609
IO1
SMBUS
TO/
FROM
HOST
+2.7V TO +5.5V
V+
IO3
IO2
GND
LOAD1
LOAD2
LOAD3
ALERT
0.1
F
P-CH
100k
100k
100k
SMBCLK
SMBDATA
SMBSUS
ADD
IO7
ADD1
Typical Operating Circuits continued at end of data sheet.
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
IO0
V+
SMBSUS
SMBCLK
ALERT
SMBDATA
ADD1
ADD0
GND
TOP VIEW
MAX1608
MAX1609
QSOP
IO1
IO2
IO5
IO3
IO4
IO6
IO7
Pin Configuration
SMBus is a trademark of Intel Corp.
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX1608/MAX1609
Octal SMBus-to-Parallel I/O Expanders
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V+ = +2.7V to +5.5V, T
A
= -40C to +85C, unless otherwise noted. Typical values are at T
A
= +25C.) (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
IO_ to GND .............................................................-0.3V to +30V
IO_ Sink Current..................................................-1mA to +50mA
SMBCLK, SMBDATA, SMBSUS
and ALERT to GND .............................................-0.3V to +6V
ADD_ to GND ...............................................-0.3V to (V+ + 0.3V)
SMBDATA and ALERT Sink Current ...................-1mA to +50mA
Continuous Power Dissipation (T
A
= +70C)
16-Pin QSOP (derate 8.3mW/C above +70C)...........667mW
Operating Temperature Range ...........................-40C to +85C
Storage Temperature Range .............................-65C to +150C
Lead Temperature (soldering, 10s) .................................+300C
10C typical hysteresis
ALERT forced to 5.5V
Static, all IOs low or pulled to 0
ALERT forced to 0.4V
SMBDATA forced to 0.6V
Static, outputs in any combination of on or off
states up to 28V
IO_, SMBSUS, SMBCLK, SMBDATA
IO_, SMBSUS, SMBCLK, SMBDATA
SMBSUS, SMBCLK, SMBDATA (Note 2)
(Note 3)
IO_ forced to 28V
10% or 90% of I/O to 10% of SMBCLK (Note 3)
IO_ to ALERT
IO_, V+ = 4.5V
IO_ forced to 1.0V, V+ = 4.5V
SMBus interface operating,
clock frequency = 100kHz
Falling edge of V+
SMBSUS to IO_
IO_ forced to 0.4V
SMBCLK to IO_
CONDITIONS
C
140
Thermal Shutdown
A
1
ALERT Output High Leakage Current
mA
1
ALERT Output Low Sink Current
mA
6
SMBus Output Low Sink Current
V
0.8
Logic Input Low Voltage
V
2.1
Logic Input High Voltage
V
0
5.5
SMBus Logic Input Voltage Range
s
3
IO_ Data Hold Time
s
10
IO_ Data Set-Up Time
10
1
s
2.5
Propagation Delay
3.5
9
A
7
18
V
2.7
5.5
Supply Voltage Range
Supply Current (Note 2)
A
0.5
2
I/O Leakage Current
mA
15
25
50
I/O Current Limit
8
13
7
V
1.2
1.8
2.5
POR Threshold Voltage
mA
2
I/O Sink Current
UNITS
MIN
TYP
MAX
PARAMETER
SMBCLK, SMBDATA
SMBDATA, SMBCLK, SMBUS, ADD_
ADD_ during address sampling (POR, SPOR,
and RAP) to V+ and GND (Note 4)
pF
5
SMBus Input Capacitance
A
-1
1
Logic Input Current
k
20
Sample Address Input Impedance
MAX1608/MAX1609
Octal SMBus-to-Parallel I/O Expanders
_______________________________________________________________________________________
3
TIMING CHARACTERISTICS
(V+ = +2.7V to +5.5V, T
A
= -40C to +85C, unless otherwise noted. Typical values are at T
A
= +25C.) (Note 1)
Note 1: Specifications from 0C to -40C are guaranteed by design, not production tested.
Note 2: For supply current, SMBus logic inputs driven to 0 or V+.
Note 3: Data hold and set-up times measured from falling edge of 9th clock.
Note 4: Must be driven to GND, V+, or floating. See SMBus Addressing section.
Note 5: The SMBus logic block is a static design and will work with clock frequencies down to DC. While slow operation is possible,
it violates the 10kHz minimum clock frequency and SMBus specifications and may use excessive space on the bus.
90% to 90% points
10% to 10% points
(Note 5)
10% or 90% of SMBDATA to 10% of SMBCLK
90% of SMBCLK to 10% of SMBDATA
10% of SMBDATA to 90% of SMBCLK
SMBCLK, SMBDATA; 10% to 90% points
SMBCLK, SMBDATA; 90% to 10% points
90% to 90% points
Master clocking in data
CONDITIONS
s
3
SMBCLK Falling Edge to
SMBDATA Valid Time
s
4
t
HIGH
SMBCLK Clock High Time
s
4.7
t
LOW
kHz
DC
100
SMBus Clock Frequency
SMBCLK Clock Low Time
ns
300
t
HD:DAT
SMBus Data Hold Time
ns
250
t
SU:DAT
SMBus Data Valid to SMBCLK
Rising Edge Time
s
4
t
SU:STO
SMBus Stop-Condition Setup
Time
s
4
t
HD:STA
SMBus Start-Condition Hold
Time
s
1
SMBus Rise Time
ns
300
SMBus Fall Time
s
4.7
SMBus Start-Condition
Setup Time
ns
500
t
SU:STA
SMBus Repeated Start-
Condition Setup Time
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
0
5.0
2.5
10.0
7.5
12.5
15.0
2.5
3.5
4.0
3.0
4.5
5.0
5.5
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX1608/9 tTOC01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
A)
IOs = 1111 1111 PULLED UP TO +28V
IOs = 0000 0000
0
5.0
2.5
10.0
7.5
12.5
15.0
-40
20
40
-20
0
60
80
100
SUPPLY CURRENT vs. TEMPERATURE
MAX1608/9 TOC02
TEMPERATURE (C)
SUPPLY CURRENT (
A)
IOs = 1111 1111 PULLED UP TO +28V
IOs = 0000 0000
0
2
4
6
8
10
12
14
16
0
2
1
3
4
5
6
IO_ SINK CURRENT
vs. SUPPLY VOLTAGE
MAX1608/9 TOC03
SUPPLY VOLTAGE (V)
SINK CURRENT (mA)
V
IO_
= 1.0V
V
IO_
= 0.4V
Typical Operating Characteristics
(V+ = +5V, T
A
= +25C, unless otherwise noted.)
MAX1608/MAX1609
Octal SMBus-to-Parallel I/O Expanders
4
_______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V+ = +5V, T
A
= +25C, unless otherwise noted.)
IO_
2V/div
ALERT
5V/div
MAX1608/9 TOC011
40ns/div
IO_ DRIVEN EXTERNALLY
ALERT DELAY
(IO_ RISING)
0
10
5
20
15
35
30
25
40
-40
0
-20
20
40
60
80
100
IO_ CURRENT LIMIT vs. TEMPERATURE
MAX1608/9 TOC04
TEMPERATURE (
C)
IO_ CURRENT LIMIT (mA)
IO_ = 0 PULLED UP TO +28V
0
10
5
20
15
25
30
0
10
15
5
20
25
30
IO_ CURRENT LIMIT vs. IO_ VOLTAGE
MAX1608/9 TOC05
V
IO_
(V)
IO_ CURRENT LIMIT (mA)
V+ = 4.5V
IO_ = 0
0
5
10
15
20
25
30
35
40
2.5
3.5
3.0
4.0
4.5
5.0
5.5
IO_ CURRENT LIMIT vs. SUPPLY VOLTAGE
MAX1608/9 TOC06
SUPPLY VOLTAGE (V)
IO_ CURRENT LIMIT (mA)
V
IO_
= 15V
IO_ = 0
0
0.3
0.2
0.1
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
10
5
15
20
25
30
IO_ BIAS CURRENT vs. IO_ VOLTAGE
MAX1608/9 TOC07
V
IO_
(V)
IO_ BIAS CURRENT (
A)
IO_ = 1
0
0.2
0.6
0.4
0.8
1.0
-40
0
-20
20
40
60
80
100
IO_ BIAS CURRENT vs. TEMPERATURE
MAX1608/9 TOC08
TEMPERATURE (
C)
IO_ BIAS CURRENT (
A)
V+ = 5V
IO_ = 1 PULLED UP TO 28V
IO_
10V/div
SMBSUS
5V/div
SUSPEND-STATE DELAY
(IO_ RISING)
MAX1608/9 TOC09
100ns/div
PULL-UP = 10k
to 28V
IO_
10V/div
SMBSUS
5V/div
MAX1608/9 TOC010
100ns/div
SUSPEND-STATE DELAY
(IO_ FALLING)
PULL-UP = 10k
to 28V
MAX1608/MAX1609
Octal SMBus-to-Parallel I/O Expanders
_______________________________________________________________________________________
5
V
IO_
500mV/div
V+
2V/div
MAX1608/9 TOC013
PULL-UP = 10k
to V+
MAX1608
IO_ POWER-UP RESPONSE
Typical Operating Characteristics (continued)
(V+ = +5V, T
A
= +25C, unless otherwise noted.)
IO_
2V/div
ALERT
5V/div
MAX1608/9 TOC012
200ns/div
IO_ DRIVEN EXTERNALLY
ALERT DELAY
(IO_ FALLING)
NAME
FUNCTION
1 8
IO0 IO7
Combined Input/Output. Open-drain output. Can withstand +28V.
9
GND
Ground
PIN
10, 11
ADD0, ADD1
SMBus Address Select. See Table 1.
12
SMBDATA
SMBus Serial-Data Input/Output. Open-drain output. Requires external pull-up resistor.
16
V+
Supply Voltage Input, +2.7V to +5.5V. Bypass to GND with a 0.1F capacitor.
15
SMBSUS
SMBus Suspend-Mode Control Input. The device will enter the state previously stored in
the suspend-mode registers if low, or enter the state previously stored in the normal-mode
registers if high.
14
SMBCLK
SMBus Serial Clock Input
13
ALERT
Active-Low Interrupt Output. Open-drain output. Requires external pull-up resistor.
Pin Description
Detailed Description
The MAX1608/MAX1609 convert 2-wire SMBus serial
data into eight latched parallel outputs (IO0IO7). These
devices are intended for general-purpose remote I/O
expansion. Each device has eight high-voltage open-
drain outputs that double as TTL-level logic inputs.
Typical applications range from high-side MOSFET load-
switch drivers in power-management systems, to push-
button switch monitors, to general-purpose digital I/Os.
The MAX1608/MAX1609 include two complete sets of
registers, each consisting of one output data register to
set the output states and two interrupt mask registers.
The SMBSUS line selects which set of registers control
the device state. The input register is used to perform
readback of the actual IO states.
The MAX1608/MAX1609 operate from a single +2.7V
to +5.5V supply with a typical quiescent current of
2.5A, making them ideal for portable applications.
Additionally, the devices include an ALERT function to
alert the master of change of condition (Figure 1).
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