19-1639; Rev 0; 1/00
Octal SMBus-to-Parallel I/O Expanders
General Description
The MAX1608/MAX1609 provide remote input/output (I/O)
expansion through an SMBus™ 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.
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
2.5µA Supply Current
o
+2.7V to +5.5V Supply Range
o
16-Pin QSOP Package
Features
o
Serial-to-Parallel or Parallel-to-Serial Conversions
MAX1608/MAX1609
Ordering Information
PART
MAX1608EEE
MAX1609EEE
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
16 QSOP
Applications
Parallel I/O Expansion
Power-Plane Switching
Notebook and Desktop Computers
Servers and Workstations
Notebook Docking Stations
Industrial Equipment
+2.7V TO +5.5V
Typical Operating Circuits
Pin Configuration
V+
100k
0.1µF
100k
100k
TOP VIEW
IO0 1
IO1 2
IO2 3
IO3 4
IO4 5
IO5 6
IO6 7
IO7 8
16 V+
15 SMBSUS
14 SMBCLK
MAX1609
ALERT
SMBUS
TO/
FROM
HOST
SMBDATA
SMBCLK
SMBSUS
IO1
IO2
IO3
P-CH
MAX1608
MAX1609
13 ALERT
12 SMBDATA
ADD1
11 ADD1
10 ADD0
9
GND
LOAD1
GND
IO7
LOAD2
LOAD3
ADD
QSOP
SMBus is a trademark of Intel Corp.
Typical Operating Circuits continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
Octal SMBus-to-Parallel I/O Expanders
MAX1608/MAX1609
ABSOLUTE MAXIMUM RATINGS
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
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)...........667mW
Operating Temperature Range ...........................-40°C to +85°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.
ELECTRICAL CHARACTERISTICS
(V+ = +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
Static, outputs in any combination of on or off
states up to 28V
Supply Current (Note 2)
Static, all IOs low or pulled to 0
SMBus interface operating,
clock frequency = 100kHz
POR Threshold Voltage
I/O Sink Current
I/O Current Limit
I/O Leakage Current
Propagation Delay
Falling edge of V+
IO_ forced to 0.4V
IO_ forced to 1.0V, V+ = 4.5V
IO_, V+ = 4.5V
IO_ forced to 28V
SMBCLK to IO_
SMBSUS
to IO_
IO_ to
ALERT
IO_ Data Set-Up Time
IO_ Data Hold Time
SMBus Logic Input Voltage Range
Logic Input High Voltage
Logic Input Low Voltage
SMBus Output Low Sink Current
ALERT
Output Low Sink Current
ALERT
Output High Leakage Current
Thermal Shutdown
Sample Address Input Impedance
Logic Input Current
SMBus Input Capacitance
10% or 90% of I/O to 10% of SMBCLK (Note 3)
(Note 3)
SMBSUS,
SMBCLK, SMBDATA (Note 2)
IO_,
SMBSUS,
SMBCLK, SMBDATA
IO_,
SMBSUS,
SMBCLK, SMBDATA
SMBDATA forced to 0.6V
ALERT
forced to 0.4V
ALERT
forced to 5.5V
10°C typical hysteresis
ADD_ during address sampling (POR, SPOR,
and RAP) to V+ and GND (Note 4)
SMBDATA, SMBCLK,
SMBUS,
ADD_
SMBCLK, SMBDATA
-1
5
140
20
1
6
1
1
10
3
0
2.1
0.8
5.5
1.2
2
8
15
13
25
0.5
50
2
2.5
1
10
µs
µs
V
V
V
mA
mA
µA
°C
kΩ
µA
pF
µs
CONDITIONS
MIN
2.7
7
3.5
7
1.8
2.5
V
mA
mA
µA
TYP
MAX
5.5
18
9
µA
UNITS
V
2
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Octal SMBus-to-Parallel I/O Expanders
TIMING CHARACTERISTICS
(V+ = +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SMBus Clock Frequency
SMBCLK Clock Low Time
SMBCLK Clock High Time
SMBus Rise Time
SMBus Fall Time
SMBus Start-Condition
Setup Time
SMBus Repeated Start-
Condition Setup Time
SMBus Start-Condition Hold
Time
SMBus Stop-Condition Setup
Time
SMBus Data Valid to SMBCLK
Rising Edge Time
SMBus Data Hold Time
SMBCLK Falling Edge to
SMBDATA Valid Time
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
t
SU:STA
t
HD:STA
t
SU:STO
t
SU:DAT
t
HD:DAT
Master clocking in data
90% to 90% points
10% of SMBDATA to 90% of SMBCLK
90% of SMBCLK to 10% of SMBDATA
10% or 90% of SMBDATA to 10% of SMBCLK
t
LOW
t
HIGH
SYMBOL
(Note 5)
10% to 10% points
90% to 90% points
SMBCLK, SMBDATA; 10% to 90% points
SMBCLK, SMBDATA; 90% to 10% points
4.7
500
4
4
250
300
3
CONDITIONS
MIN
DC
4.7
4
1
300
TYP
MAX
100
UNITS
kHz
µs
µs
µs
ns
µs
ns
µs
µs
ns
ns
µs
MAX1608/MAX1609
Specifications from 0°C to -40°C are guaranteed by design, not production tested.
For supply current, SMBus logic inputs driven to 0 or V+.
Data hold and set-up times measured from falling edge of 9th clock.
Must be driven to GND, V+, or floating. See
SMBus Addressing
section.
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.
Typical Operating Characteristics
(V+ = +5V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX1608/9 tTOC01
SUPPLY CURRENT vs. TEMPERATURE
MAX1608/9 TOC02
IO_ SINK CURRENT
vs. SUPPLY VOLTAGE
14
V
IO_
= 1.0V
SINK CURRENT (mA)
12
10
8
6
4
V
IO_
= 0.4V
MAX1608/9 TOC03
15.0
12.5
SUPPLY CURRENT (µA)
10.0
7.5
IOs = 0000 0000
5.0
2.5
0
2.5
3.0
3.5
4.0
4.5
5.0
IOs = 1111 1111 PULLED UP TO +28V
15.0
12.5
SUPPLY CURRENT (µA)
10.0
7.5
5.0
2.5
0
IOs = 1111 1111 PULLED UP TO +28V
16
IOs = 0000 0000
2
0
-40
-20
0
20
40
60
80
100
0
1
2
3
4
5
6
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
5.5
SUPPLY VOLTAGE (V)
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Octal SMBus-to-Parallel I/O Expanders
MAX1608/MAX1609
Typical Operating Characteristics (continued)
(V+ = +5V, T
A
= +25°C, unless otherwise noted.)
IO_ CURRENT LIMIT vs. TEMPERATURE
MAX1608/9 TOC04
IO_ CURRENT LIMIT vs. IO_ VOLTAGE
MAX1608/9 TOC05
IO_ CURRENT LIMIT vs. SUPPLY VOLTAGE
35
IO_ CURRENT LIMIT (mA)
30
25
20
15
10
5
0
2.5
3.0
3.5
4.0
4.5
V
IO_
= 15V
IO_ = 0
5.0
5.5
MAX1608/9 TOC06
40
IO_ = 0 PULLED UP TO +28V
35
IO_ CURRENT LIMIT (mA)
30
25
20
15
10
5
0
-40
-20
0
20
40
60
80
30
25
IO_ CURRENT LIMIT (mA)
20
15
10
5
0
40
V+ = 4.5V
IO_ = 0
0
5
10
15
V
IO_
(V)
20
25
30
100
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
IO_ BIAS CURRENT vs. IO_ VOLTAGE
MAX1608/9 TOC07
IO_ BIAS CURRENT vs. TEMPERATURE
MAX1608/9 TOC08
SUSPEND-STATE DELAY
(IO_ RISING)
PULL-UP = 10kΩ to 28V
MAX1608/9 TOC09
1.0
0.9
0.8
IO_ BIAS CURRENT (µA)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
5
10
15
V
IO_
(V)
20
25
IO_ = 1
1.0
V+ = 5V
IO_ = 1 PULLED UP TO 28V
0.8
IO_ BIAS CURRENT (µA)
0.6
IO_
10V/div
0.4
SMBSUS
5V/div
0.2
30
0
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
100ns/div
SUSPEND-STATE DELAY
(IO_ FALLING)
MAX1608/9 TOC010
ALERT DELAY
(IO_ RISING)
MAX1608/9 TOC011
PULL-UP = 10kΩ to 28V
IO_
10V/div
IO_
2V/div
SMBSUS
5V/div
IO_ DRIVEN EXTERNALLY
100ns/div
40ns/div
ALERT
5V/div
4
_______________________________________________________________________________________
Octal SMBus-to-Parallel I/O Expanders
Typical Operating Characteristics (continued)
(V+ = +5V, T
A
= +25°C, unless otherwise noted.)
MAX1608/MAX1609
ALERT DELAY
(IO_ FALLING)
MAX1608/9 TOC012
MAX1608
IO_ POWER-UP RESPONSE
PULL-UP = 10kΩ to V+
MAX1608/9 TOC013
IO_
2V/div
V
IO_
500mV/div
ALERT
5V/div
IO_ DRIVEN EXTERNALLY
200ns/div
V+
2V/div
Pin Description
PIN
1– 8
9
10, 11
12
13
14
15
16
NAME
IO0– IO7
GND
ADD0, ADD1
SMBDATA
ALERT
SMBCLK
SMBSUS
V+
FUNCTION
Combined Input/Output. Open-drain output. Can withstand +28V.
Ground
SMBus Address Select. See Table 1.
SMBus Serial-Data Input/Output. Open-drain output. Requires external pull-up resistor.
Active-Low Interrupt Output. Open-drain output. Requires external pull-up resistor.
SMBus Serial Clock Input
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.
Supply Voltage Input, +2.7V to +5.5V. Bypass to GND with a 0.1µF capacitor.
Detailed Description
The MAX1608/MAX1609 convert 2-wire SMBus serial
data into eight latched parallel outputs (IO0–IO7). 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
2.5µA, 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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5