General Description Benefits and Features

General Description Benefits and Features
EVALUATION KIT AVAILABLE
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
General Description
The MAX7320 2-wire serial-interfaced peripheral features
eight push-pull outputs with selectable power-up logic
states.
The +5.5V tolerant RST input clears the serial interface, terminating any I2C communication to or from the
MAX7320.
The MAX7320 uses two address inputs with four-level
logic to allow 16 I2C slave addresses. The slave address
also determines the power-up state level for the outputs
in groups of four ports.
The MAX7320 supports hot insertion. The serial interface
SDA, SCL, AD0, AD2, and RST remain high impedance in
power-down (V+ = 0V) with up to +6V asserted on them.
The MAX7320 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 MAX7320 is available in 16-pin QSOP and 16-pin
TQFN packages, and is specified over the automotive
temperature range (-40°C to +125°C).
Benefits and Features
●● 400kHz, +5.5V-Tolerant I2C Serial Interface
●● +1.71V to +5.5V Operating Voltage
●● Eight Push-Pull Output Ports with Selectable PowerUp Logic States
●● RST Clears the Serial Interface, Terminating Any
Serial Transaction to or from the MAX7320
●● AD0 and AD2 Inputs Select from 16 Slave Addresses
●● Low 0.6μA (typ) Standby Current
●● -40°C to +125°C Temperature Range
Ordering Information
PINPACKAGE
PART
TEMP RANGE
MAX7320AEE+
-40°C to +125°C
16 QSOP
MAX7320ATE+
-40°C to +125°C
16 TQFN
3mm x 3mm x
0.8mm
TOP
MARK
—
ADB
+Denotes a lead(Pb)-free/RoHS-compliant package.
Applications
●● Cell Phones/PDAs
●● Satellite Radios
●● Notebooks
●● RAID
●● Servers
Pin Configurations, Typical Application Circuit, and
Functional Diagram appear at end of data sheet.
Selector Guide
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
MAX7328*
MAX7329**
Up to 8
*Second source to PCF8574.
**Second source to PCF8574A.
19-3879; Rev 1; 4/15
—
—
Up to 8
4
—
—
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Absolute Maximum Ratings
(All voltages referenced to GND.)
Supply Voltage V+....................................................-0.3V to +6V
SCL, SDA, AD0, AD2, RST.......................................-0.3V to +6V
O0–07.............................................................0.3V to (V+ + 0.3V)
00–07 Output Current .......................................................±25mA
SDA Input Current.............................................................. 10mA
Total V+ Current..................................................................50mA
Total GND Current ...........................................................100mA
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP (derate 8.3mW/°C over +70°C).............667mW
16-Pin Thin QFN (derate 15.6mW/°C over +70°C)....1250mW
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.
Electrical 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.) (Note 1)
PARAMETER
SYMBOL
Operating Supply Voltage
V+
Power-On Reset Voltage
VPOR
Standby Current Voltage
(Interface Idle)
ISTB
Supply Current (Interface
Running)
I+
Input High-Voltage
SDA, SCL, AD0, AD2, RST
VIH
Input Low-Voltage
SDA, SCL, AD0, AD2, RST
VIL
Input Leakage Current
SDA, SCL, AD0, AD2, RST
IIH, IIL
CONDITIONS
Output Low Voltage SDA
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MAX
UNITS
5.50
V
1.6
V
0.6
1.5
µA
fSCL = 400kHz; other digital inputs at V+
23
55
µA
V+ < 1.8V
0.8 x V+
V+ ≥ 1.8V
0.7 x V+
V
V+ < 1.8V
0.2 x V+
V+ ≥ 1.8V
0.3 x V+
SDA, SCL, AD0, AD2, RST, O0–O7 at V+
or GND
-0.2
+0.2
10
VOL
VOH
VOLSDA
120
240
V+ = +2.5V, ISINK = 2mA
140
280
V+ = +3.3V, ISINK = 3mA
170
310
220
380
V+ = +1.71V, ISOURCE = 1mA
V+ - 250 V+ - 130
V+ = +2.5V, ISOURCE = 2mA
V+ - 350 V+ - 200
V+ = +3.3V, ISOURCE = 3mA
V+ - 290 V+ - 150
V+ = +5V, ISOURCE = 5mA
V+ - 380 V+ - 230
ISINK = 6mA
V
µA
pF
V+ = +1.71V, ISINK = 1mA
V+ = +5V, ISINK = 5mA
Output High Voltage
O0–O7
TYP
SCL and SDA and other digital inputs at V+
Input Capacitance
SDA, SCL, AD0, AD2, RST
Output Low Voltage
O0–O7
MIN
1.71
mV
mV
250
mV
Maxim Integrated │ 2
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Port And 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.) (Note 1)
PARAMETER
Port Output Data Valid
SYMBOL
tPPV
CONDITIONS
MIN
TYP
CL ≤ 100pF
MAX
UNITS
4
µs
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.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
400
kHz
Serial Clock Frequency
fSCL
Bus Free Time Between a STOP
and a START Condition
tBUF
1.3
µs
Hold Time (Repeated) START
Condition
tHD, STA
0.6
µs
Repeated START Condition Setup
Time
tSU, STA
0.6
µs
STOP Condition Setup Time
tSU, STO
0.6
µs
Data Hold Time
tHD, DAT
Data Setup Time
tSU, DAT
SCL Low to Data Out Valid
tVD, DAT
(Note 3)
0.9
µs
3.4
µs
100
ns
SCL low to SDA output valid
SCL Clock Low Period
tLOW
1.3
µs
SCL Clock High Period
tHIGH
0.7
µs
Rise Time of Both SDA and SCL
Signals, Receiving
tR
(Notes 2, 4)
20 +
0.1Cb
300
ns
Fall Time of Both SDA and SCL
Signals, Receiving
tF
(Notes 2, 4)
20 +
0.1Cb
300
ns
tF,TX
(Notes 2, 4)
20 +
0.1Cb
250
ns
Fall Time of SDA Transmitting
Pulse Width of Spike Suppressed
tSP
(Note 5)
Capacitive Load for Each
Bus Line
Cb
(Note 2)
RST Pulse Width
tW
500
ns
tRST
1
µs
RST Rising to START Condition
Setup Time
50
ns
400
pF
Note 1: All parameters tested at TA = +25°C. Specifications over temperature are guaranteed by design.
Note 2: Guaranteed by design.
Note 3: A master device must provide a hold time of at least 300ns for the SDA signal (referred to VIL of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 4:Cb = total capacitance of one bus line in pF. tR and tF measured between 0.3 x V+ and 0.7 x V+, ISINK ≤ 6mA.
Note 5: Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
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Maxim Integrated │ 3
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
V+ = +5.0V
1.0
V+ = +2.5V
0.8
V+ = +3.3V
0.6
0.4
0
V+ = +1.71V
20
10
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
OUTPUT VOLTAGE HIGH
vs. TEMPERATURE
MAX7320 toc03
0.25
V+ = +1.71V
OUTPUT VOLTAGE LOW
vs. TEMPERATURE
V+ = +5.0V
ISINK = 5mA
0.30
V+ = +2.5V
TEMPERATURE (°C)
0.40
0.35
V+ = +3.3V
30
TEMPERATURE (°C)
0.45
V+ = +2.5V
ISINK = 2mA
V+ = +3.3V
ISINK = 3mA
0.20
0.15
0.10
V+ = +1.71V
ISINK = 1mA
0.05
0
40
-40 -25 -10 5 20 35 50 65 80 95 110 125
0.50
fSCL = 400kHz
V+ = +5.0V
6
V+ = +5.0V
ISOURCE = 5mA
5
4
MAX7320 toc04
1.2
0.2
OUTPUT VOLTAGE LOW (V)
SUPPLY CURRENT (µA)
1.4
SUPPLY CURRENT vs. TEMPERATURE
50
OUTPUT VOLTAGE HIGH (V)
STANDBY CURRENT (µA)
1.6
MAX7320 toc01
fSCL = 0kHz
1.8
60
MAX7320 toc02
STANDBY CURRENT vs. TEMPERATURE
2.0
V+ = +3.3V
ISOURCE = 3mA
3
2
1
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
V+ = +2.5V
ISOURCE = 2mA
V+ = +1.71V
ISOURCE = 1mA
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Pin Description
PIN
QSOP
TQFN
1, 3
15, 1
NAME
FUNCTION
AD0, AD2
Address Inputs. Select device slave address with AD0 and AD2. Connect AD0 and AD2 to
either GND, V+, SCL, or SDA to give four logic combinations (see Table 3).
2
16
RST
4–7, 9–12
2–5, 7–10
O0–O7
8
6
GND
Ground
13
11
N.C.
No Connection. Not internally connected.
14
12
SCL
I2C-Compatible Serial Clock Input
15
13
SDA
I2C-Compatible Serial Data I/O
16
14
V+
Positive Supply Voltage. Bypass V+ to GND with a 0.047µF ceramic capacitor.
—
EP
EP
Exposed Pad. Connect exposed pad to GND.
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Reset Input, Active Low. Drive RST low to clear the 2-wire interface.
Output Ports. O0 to O7 are push-pull outputs.
Maxim Integrated │ 4
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Detailed Description
Functional Overview
MAX7319–MAX7329 Family Comparison
The MAX7319–MAX7323 family consists of five pin-compatible, eight-port expanders. Each version is optimized
for different applications. The MAX7328 and MAX7329
are second sources to the PCF8574 and PCF8574A.
The MAX7324–MAX7327 family consists of four pin-compatible, 16-port expanders that integrate the functions of
the MAX7320 and one of either the MAX7319, MAX7321,
MAX7322, or MAX7323.
The MAX7320 is a general-purpose port expander operating from a +1.71V to +5.5V supply that provides eight
push-pull output ports. The MAX7320 is rated to sink a
total of 100mA and source a total of 50mA from all eight
combined outputs.
The MAX7320 is set to one of 16 I2C slave addresses
(0x50 to 0x5F) using address select inputs AD0 and AD2,
and is accessed over an I2C serial interface up to 400kHz.
Note the MAX7320 offers a different range of I2C slave
addresses than the MAX7319, MAX7321, MAX7322, and
MAX7323 (these expanders use the address range 0x60
to 0x6F).
Table 1. MAX7319–MAX7329 Family Comparison
PART
INPUT
I2C SLAVE
INPUTS INTERRUPT
ADDRESS
MASK
OPENDRAIN
OUTPUTS
PUSHPULL
OUTPUTS
APPLICATION
8-PORT EXPANDERS
MAX7319
MAX7320
MAX7321
MAX7322
110xxxx
101xxxx
110xxxx
110xxxx
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8
—
Up to 8
4
Yes
—
—
Yes
—
—
Up to 8
—
—
Input-only versions:
Eight input ports with programmable latching
transition detection interrupt and selectable pullups.
Offers maximum versatility for automatic input
monitoring. An interrupt mask selects which inputs
cause an interrupt on transitions, and transition
flags identify which inputs have changed (even
momentarily) since the ports were last read.
8
Output-only versions:
Eight push-pull outputs with selectable power-up
default states.
Push-pull outputs offer faster rise time than opendrain outputs, and require no pullup resistors.
—
I/O versions:
Eight open-drain I/O ports with latching transition
detection interrupt and selectable pullups.
Open-drain outputs can level shift the logic-high state
to a higher or lower voltage than V+ using external
pullup resistors. Any port can be used as an input by
setting the open-drain output to logic-high. Transition
flags identify which inputs have changed (even
momentarily) since the ports were last read.
4
Four input-only, four output-only versions:
Four input ports with programmable latching transition
detection interrupt and selectable pullups.
Four push-pull outputs with selectable power-up
default levels.
Maxim Integrated │ 5
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Table 1. MAX7319–MAX7329 Family Comparison (continued)
PART
MAX7323
MAX7328
MAX7329
INPUT
I2C SLAVE
INPUTS INTERRUPT
ADDRESS
MASK
110xxxx
0100xxx
0111xxx
Up to 4
—
Up to 8
—
OPENDRAIN
OUTPUTS
PUSHPULL
OUTPUTS
APPLICATION
4
Four I/O, four output-only versions:
Four open-drain I/O ports with latching transition
detection interrupt and selectable pullups.
Four push-pull outputs with selectable power-up
default levels.
Up to 8
—
PCF8574-, PCF8574A-compatible versions:
Eight open-drain I/O ports with nonlatching transition
detection interrupt and pullups on all ports.
All ports power up as inputs (or logic-high outputs).
Any port can be used as an input by setting the opendrain output to logic-high.
Up to 4
16-PORT EXPANDERS
MAX7324
MAX7325
MAX7326
101xxxx
and
110xxxx
MAX7327
8
Yes
—
8
Software equivalent to a MAX7320 plus a MAX7321.
Up to 8
—
Up to 8
8
Software equivalent to a MAX7320 plus a MAX7319.
4
Yes
—
12
Software equivalent to a MAX7320 plus a MAX7322.
Up to 4
—
Up to 4
12
Software equivalent to a MAX7320 plus a MAX7323.
Table 2. Read and Write Access to Eight-Port Expander Family
PART
I2C SLAVE
ADDRESS
INPUTS
INTERRUPT
MASK
OPENDRAIN
OUTPUTS
PUSHPULL
OUTPUTS
I2C DATA WRITE
I2C DATA READ
MAX7319
110xxxx
8
Yes
—
—
<I7–I0 interrupt
mask>
<I7–I0 port inputs>
<I7–I0 transition flags>
MAX7320
101xxxx
—
—
—
8
<O7–O0 port
outputs>
<O7-O0 port inputs>
MAX7321
110xxxx
Up to 8
—
Up to 8
—
<P7–P0 port
outputs>
<P7–P0 port inputs>
<P7–P0 transition flags>
4
<O7, O6 outputs,
I5–I2 interrupt
mask, O1, O0
outputs>
<O7, O6, I5–I2, O1, O0 port
inputs>
<0, 0, I5–I2 transition flags,
0, 0>
MAX7322
110xxxx
4
Yes
—
MAX7323
110xxxx
Up to 4
—
Up to 4
4
<port outputs>
<O7, O6, P5–P2, O1, O0 port
inputs>
<0, 0, P5-P2 transition flags,
0, 0>
MAX7328
0100xxx
Up to 8
—
Up to 8
—
<P7–P0 port
outputs>
<P7–P0 port inputs>
MAX7329
0111xxx
Up to 8
—
Up to 8
—
<P7–P0 port
outputs>
<P7–P0 port inputs>
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Maxim Integrated │ 6
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Table 3. MAX7320 Address Map
PIN
CONNECTION
DEVICE ADDRESS
OUTPUTS POWER-UP DEFAULT
AD2
AD0
A6
A5
A4
A3
A2
A1
A0
O7
O6
O5
O4
O3
O2
O1
O0
SCL
GND
1
0
1
0
0
0
0
1
1
1
1
0
0
0
0
SCL
V+
1
0
1
0
0
0
1
1
1
1
1
1
1
1
1
SCL
SCL
1
0
1
0
0
1
0
1
1
1
1
1
1
1
1
SCL
SDA
1
0
1
0
0
1
1
1
1
1
1
1
1
1
1
SDA
GND
1
0
1
0
1
0
0
1
1
1
1
0
0
0
0
SDA
V+
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
SDA
SCL
1
0
1
0
1
1
0
1
1
1
1
1
1
1
1
SDA
SDA
1
0
1
0
1
1
1
1
1
1
1
1
1
1
1
GND
GND
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
GND
V+
1
0
1
1
0
0
1
0
0
0
0
1
1
1
1
GND
SCL
1
0
1
1
0
1
0
0
0
0
0
1
1
1
1
GND
SDA
1
0
1
1
0
1
1
0
0
0
0
1
1
1
1
V+
GND
1
0
1
1
1
0
0
1
1
1
1
0
0
0
0
V+
V+
1
0
1
1
1
0
1
1
1
1
1
1
1
1
1
V+
SCL
1
0
1
1
1
1
0
1
1
1
1
1
1
1
1
V+
SDA
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
The RST input clears the serial interface in case of a
hung bus, terminating any serial transaction to or from
the MAX7320.
When the MAX7320 is read through the serial interface,
the actual logic states at the ports are read back.
Output port power-up logic states are selected by the
address select inputs AD0 and AD2. Ports default to
logic-high or logic-low on power-up in groups of four (see
Table 3).
RST Input
The RST input voids any I2C transaction involving the
MAX7320 and forces the MAX7320 into the I2C STOP
condition. A reset does not change the contents of the
output register. RST is overvoltage tolerant to +5.5V.
Standby Mode
When the serial interface is idle, the MAX7320 automatically enters standby mode, drawing minimal supply current.
Slave Address and Power-Up
Default Logic States
Address inputs AD0 and AD2 determine the MAX7320
slave address and set the power-up output logic states.
Power-up logic states are set in groups of four (see
Table 3). The MAX7320 uses a different range of slave
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addresses (101xxxx) than the MAX7319, MAX7321,
MAX7322, and MAX7323 (110xxxx).
The MAX7320 slave address is determined on each
I2C transmission, regardless of whether the transmission is actually addressing the MAX7320. The MAX7320
distinguishes whether address inputs AD0 and AD2 are
connected to SDA or SCL instead of fixed logic levels V+
or GND during this transmission. This means that the
MAX7320 slave address can be configured dynamically in
the application without cycling the device supply.
On initial power-up, the MAX7320 cannot decode the
address inputs AD0 and AD2 fully until the first I2C transmission. AD0 and AD2 initially appear to be connected to
V+ or GND. This is important because the address selection determines the power-up logic levels of the output
ports. However, at power-up, the I2C SDA and SCL bus
interface lines are high impedance at the pins of every
device (master or slave) connected to the bus, including
the MAX7320. This is guaranteed as part of the I2C specification. Therefore, address inputs AD0 and AD2 that are
connected to SDA or SCL normally appear at power-up
to be connected to V+. The power-up output state selection logic uses AD0 to select the power-up state for ports
O3–O0, and uses AD2 to select the power-up state for
ports O7–O4. The rule is that a logic-high, SDA, or SCL
connection selects a logic-high power-up state, and a
Maxim Integrated │ 7
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
SDA
tSU,STA
tSU,DAT
tLOW
tHD,STA
tHD,DAT
tBUF
tSU,STO
tHIGH
SCL
tHD,STA
tR
tF
START CONDITION
tVD,DAT
REPEATED START CONDITION
STOP
CONDITION
START
CONDITION
Figure 1. 2-Wire Serial-Interface Timing Details
logic-low selects a logic-low power-up state for each set
of four ports (see Table 3). The output power-up logic
level configuration is correct for a standard I2C configuration, where SDA or SCL appear to be connected to V+ by
the external I2C pullups.
There are circumstances where the assumption that SDA
= SCL = V+ on power-up is not true; for example, in true
hot-swap applications in which there is legitimate bus
activity during power-up. Also, if SDA and SCL are terminated with pullup resistors to a different supply voltage
than the MAX7320’s supply, and if that pullup supply rises
later than the MAX7320’s, then SDA or SCL may appear
at power-up to be connected to GND. In such applications, use the four address combinations that are selected
by connecting address inputs AD0 and AD2 to GND or V+
(shown in bold in Table 3). These selections are guaranteed to be correct at power-up, independent of SDA and
SCL behavior. If one of the other 12 address combinations
is used, be aware that unexpected port power-up default
states may occur until the first I2C transmission (to any
device, not necessarily the MAX7320).
Port Outputs
Write one byte to the MAX7320 to set all output port
states simultaneously.
Serial Interface
Serial-Addressing
The MAX7320 operates as a slave that sends and
receives data through an I2C interface. The interface uses
a serial data line (SDA) and a serial clock line (SCL) to
achieve bidirectional communication between master(s)
and slave(s). A master initiates all data transfers to and
from the MAX7320, and generates the SCL clock that
synchronizes the data transfer (Figure 1).
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SDA
SCL
S
P
START
CONDITION
STOP
CONDITION
Figure 2. START and STOP Conditions
SDA operates as both an input and an open-drain output.
A pullup resistor, 4.7kΩ (typ), is required on SDA. SCL
operates only as an input. A pullup resistor, 4.7kΩ (typ),
is required on SCL if there are multiple masters on the 2wire interface, or if the master in a single-master system
has an open-drain SCL output.
Each transmission consists of a START condition sent by
a master, followed by the MAX7320’s 7-bit slave address
plus R/W bit, one or more data bytes, and finally a STOP
condition (Figure 2).
START and STOP Conditions
Both SCL and SDA remain high when the interface is not
busy. A master signals the beginning of a transmission
with a START (S) condition by transitioning SDA from high
to low while SCL is high. When the master has finished
communicating with the slave, the master issues a STOP
(P) condition by transitioning SDA from low to high while
SCL is high. The bus is then free for another transmission
(Figure 2).
Bit Transfer
One data bit is transferred during each clock pulse.
The data on SDA must remain stable while SCL is high
(Figure 3).
Maxim Integrated │ 8
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Acknowledge
The acknowledge bit is a clocked 9th bit the recipient uses to acknowledge receipt of each byte of data
(Figure 4). Each byte transferred effectively requires 9
bits. The master generates the ninth clock pulse, and the
recipient pulls down SDA during the acknowledge clock
pulse, such that the SDA line is stable low during the high
period of the clock pulse. When the master is transmitting
to the MAX7320, the device generates the acknowledge
bit because the MAX7320 is the recipient. When the
MAX7320 is transmitting to the master, the master generates the acknowledge bit because the master is the
recipient.
Slave Address
The MAX7320 has a 7-bit slave address (Figure 5). The
8th bit following the 7-bit slave address is the R/W bit. It is
low for a write command, and high for a read command.
The 1st (A6), 2nd (A5), and 3rd (A4) bits of the MAX7320
slave address are always 1, 0, and 1. Connect AD0 and
AD2 to GND, V+, SDA, or SCL to select the slave address
bits A3, A2, A1, and A0. The MAX7320 has 16 possible
slave addresses (Table 3), allowing up to 16 MAX7320
devices on an I2C bus.
Note the MAX7320 offers a different range of I2C slave
addresses from the MAX7319, MAX7321, MAX7322 and
MAX7323, for which 1st (A6), 2nd (A5), and 3rd (A4) bits
of the slave address are always 1, 1, and 0.
Accessing the MAX7320
A single-byte read from the MAX7320 returns the status
of the eight output ports, read back as inputs.
A 2-byte read repeatedly returns the status of the eight
output ports, read back as inputs.
A multibyte read (more than 2 bytes before the I2C
STOP bit) repeatedly returns the status of the eight output
ports, read back as inputs.
A single-byte write to the MAX7320 sets the logic state
of all eight outputs.
A multibyte write to the MAX7320 repeatedly sets the
logic state of all eight outputs.
Reading from the MAX7320
A read from the MAX7320 starts with the master transmitting the MAX7320’s slave address with the R/W bit set
high. The MAX7320 acknowledges the slave address,
and samples the logic state of the output ports during
www.maximintegrated.com
SDA
SCL
DATA LINE STABLE; CHANGE OF DATA
DATA VALID
ALLOWED
Figure 3. Bit Transfer
CLOCK PULSE
FOR ACKNOWLEDGMENT
START
CONDITION
SCL
1
2
8
9
SDA BY
TRANSMITTER
SDA BY
RECEIVER
S
Figure 4. Acknowledge
the acknowledge bit. The master can read one or more
bytes from the MAX7320 and then issue a STOP condition (Figure 6). The MAX7320 transmits the current port
data, read back from the actual port outputs (not the port
output latches) during the acknowledge. If a port is forced
to a logic state other than its programmed state, the read
back reflects this. If driving a capacitive load, readback
port level verification algorithms may need to take the RC
rise/fall time into account.
Typically, the master reads one byte from the MAX7320,
then issues a STOP condition (Figure 6). However, the
master can read 2 or more bytes from the MAX7320,
then issue a STOP condition. In this case, the MAX7320
resamples the port outputs during each acknowledge and
transmits the new data each time.
Writing to the MAX7320
A write to the MAX7320 starts with the master transmitting the MAX7320’s slave address with the R/W bit set
low. The MAX7320 acknowledges the slave address and
samples the ports during the acknowledge bit. The master
can transmit one or more bytes of data. The MAX7320
acknowledges each subsequent byte of data and updates
the output ports until the master issues a STOP condition
(Figure 7).
Maxim Integrated │ 9
MAX7320
SDA
I2C Port Expander with Eight Push-Pull Outputs
1
1
0
A3
A2
A1
A0
R/W
ACK
LSB
MSB
SCL
Figure 5. Slave Address
PORT SNAPSHOT DATA
S
1
0
1
MAX7320 SLAVE ADDRESS
1
R/W
A
O7
O6
O5
O4
O3
DATA 1
O2
O1
O0
D7
D6
D5
D4
D2
D1
D0
D3
PORT SNAPSHOT TAKEN
N
P
ACKNOWLEDGE
FROM MASTER
PORT SNAPSHOT TAKEN
SCL
S = START CONDITION
P = STOP CONDITION
SHADED = SLAVE TRANSMISSION
N = NOT ACKNOWLEDGE
Figure 6. Reading the MAX7320
1
SCL
2
3
4
5
6
7
8
DATA TO PORT
SLAVE ADDRESS
SDA
S
START CONDITION
DATA OUT
FROM PORT
0
A
DATA TO PORT
DATA 1
A
DATA 2
A
ACKNOWLEDGE
FROM SLAVE
R/W ACKNOWLEDGE
FROM SLAVE
ACKNOWLEDGE
FROM SLAVE
DATA 1 VALID
tPPV
DATA 2 VALID
tPPV
Figure 7. Writing to the MAX7320
www.maximintegrated.com
Maxim Integrated │ 10
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Functional Block Diagram
V+
AD0
AD2
SCL
SDA
RST
INPUT
FILTER
I2 C
CONTROL
OUTPUT
PORTS
O7
O6
O5
O4
O3
O2
O1
O0
POWERON RESET
MAX7320
GND
Applications Information
Hot Insertion
SDA, SCL, AD0, AD2, and RST are overvoltage protected
to +6V independent of V+. This allows the MAX7320 to
be operated from a lower supply voltage, such as +3.3V,
while the I2C interface is driven from a higher logic level,
such as +5V.
Each of the output ports, O0–O7, has a protection diode
to V+ and to GND (Figure 8). When a port output is driven
to a voltage higher than V+ or lower than GND, the appropriate protection diode clamps the output to a diode drop
above V+ or below GND. When the MAX7320 is powered
down (V+ = 0V), each output port appears as a diode connected to GND (Figure 8).
V+
V+
MAX7320
PORT
Figure 8. Output Port Structure
Power-Supply Considerations
The MAX7320 operates with a supply voltage of +1.71V
to +5.5V over the -40°C to +125°C temperature range.
Bypass V+ to GND with a ceramic capacitor of at least
0.047μF as close to the device as possible. For the TQFN
version, additionally connect the exposed pad to GND.
www.maximintegrated.com
Maxim Integrated │ 11
I2C Port Expander with Eight Push-Pull Outputs
16
TQFN
MAX7320
MAX7315
MAX6965 AND
MAX7316
1
2
15
AD0
AD0
BLINK
16
RST
AD1
RST
3
1
AD2
AD2
AD0
Typical Application Circuit
O7
O6
9
V+ 14
MAX7320
AD0 15
*EP
+
1
2
3
4
O2
16
QSOP
10
SDA 13
RST 16
PIN FUNCTION
11
AD2
PIN-PACKAGE
12
O1
Table 4. MAX7320, MAX6965, MAX7315,
and MAX7316 Pin Compatibility
TOP VIEW
N.C.
The MAX7320 is subset pin compatible with the MAX6965,
MAX7315, and MAX7316. The pin differences are shown
in Table 4. The MAX7320 is not software compatible with
MAX6965, MAX7315, or MAX7316. In many cases it is
possible to design a PC board to work with all these port
expanders, providing design flexibility.
Pin Configurations
O0
Compatibility with MAX6965, MAX7315,
and MAX7316
SCL
MAX7320
+
O0 4
µC
SCL
SCL
SDA
SDA
O6
RST
RST
O5
MAX7320
O4
O3
O2
AD0
AD2
GND
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O7
O1
O0
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
O4
6
GND
5
O3
16 V+
15 SDA
14 SCL
AD2 3
V+
7
*EXPOSED PAD. CONNECT TO GND.
RST 2
47nF
O5
TQFN
3mm x 3mm x 0.8mm
AD0 1
+3.3V
8
MAX7320
13 N.C.
O1 5
12 O7
O2 6
11 O6
O3 7
10 O5
9
GND 8
O4
QSOP
Chip Information
PROCESS: BiCMOS
Connect EP to GND
Maxim Integrated │ 12
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
LAND PATTERN NO.
16 QSOP
E16+4
21-0055
90-0167
16 TQFN-EP
T1633+4
21-0136
90-0031
www.maximintegrated.com
Maxim Integrated │ 13
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Revision History
REVISION
NUMBER
REVISION
DATE
0
10/05
Initial release
—
1
4/15
Removed automotive reference from data sheet
1
DESCRIPTION
PAGES
CHANGED
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2015 Maxim Integrated Products, Inc. │ 14
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