19-3879; Rev 0; 10/05
EVALUATION KIT
AVAILABLE
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).
Applications
Cell Phones/PDAs
Satellite Radios
Notebooks
Automotive
RAID
Servers
Features
♦ 400kHz, +5.5V-Tolerant I2C Serial Interface
♦ +1.71V to +5.5V Operating Voltage
♦ Eight Push-Pull Output Ports with Selectable
Power-Up 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
PART
MAX7320AEE+
MAX7320ATE+
+Denotes lead-free package.
TEMP
RANGE
-40°C to
+125°C
-40°C to
+125°C
PINPACKAGE
16 QSOP — E16-4
16 TQFN
3mm x 3mm
x 0.8mm
TOP
MARK
ADB T1633-4
PKG
CODE
MAX7320
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 4
MAX7328* — —
MAX7329**
*Second source to PCF8574.
**Second source to PCF8574A.
†
a
P
C
l
S.
________________________________________________________________ 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.
Up to 8
—
Up to 8
—
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
(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 (T
A
= +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
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 CONDITIONS MIN TYP MAX UNITS
Operating Supply Voltage V+ 1.71 5.50 V
Power-On Reset Voltage V
Standby Current Voltage
(Interface Idle)
Supply Current
(Interface Running)
Input High-Voltage
SDA, SCL, AD0, AD2, RST
Input Low-Voltage
SDA, SCL, AD0, AD2, RST
Input Leakage Current
SDA, SCL, AD0, AD2, RST
Input Capacitance
SDA, SCL, AD0, AD2, RST
Output Low Voltage
O0–O7
Output High Voltage
O0–O7
Output Low Voltage SDA V
POR
I
STB
V
V
I
IH
V
V
OLSDAISINK
SCL and SDA and other digital inputs at V+ 0.6 1.5 µA
I+ f
OL
OH
SCL
V+ < 1.8V 0.8 x V+
IH
V+ ≥ 1.8V 0.7 x V+
V+ < 1.8V 0.2 x V+
IL
V+ ≥ 1.8V 0.3 x V+
SDA, SCL, AD0, AD2, RST, O0–O7 at V+ or
, I
IL
GND
V+ = +1.71V, I
V+ = +2.5V, I
V+ = +3.3V, I
V+ = +5V, I
V+ = +1.71V, I
V+ = +2.5V, I
V+ = +3.3V, I
V+ = +5V, I
= 400kHz; other digital inputs at V+ 23 55 µA
-0.2 +0.2 µA
10 pF
= 1mA 120 240
SINK
= 2mA 140 280
SINK
= 3mA 170 310
SINK
= 5mA 220 380
SINK
SOURCE
SOURCE
SOURCE
SOURCE
= 6mA 250 mV
= 1mA V+ - 250 V+ - 130
= 2mA V+ - 350 V+ - 200
= 3mA V+ - 290 V+ - 150
= 5mA V+ - 380 V+ - 230
1.6 V
V
V
mV
mV
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
_______________________________________________________________________________________ 3
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)
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)
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 V
IL
of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 4: C
b
= total capacitance of one bus line in pF. tRand tFmeasured between 0.3 x V+ and 0.7 x V+, I
SINK
≤ 6mA.
Note 5: Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Port Output Data Valid t
PPV
CL ≤ 100pF 4 µs
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Serial Clock Frequency f
Bus Free Time Between a STOP
and a START Condition
Hold Time (Repeated) START
Condition
Repeated START Condition
Setup Time
STOP Condition Setup Time
Data Hold Time
Data Setup Time
SCL Low to Data Out Valid t
SCL Clock Low Period t
SCL Clock High Period t
Rise Time of Both SDA and SCL
Signals, Receiving
Fall Time of Both SDA and SCL
Signals, Receiving
Fall Time of SDA Transmitting t
Pulse Width of Spike Suppressed
Capacitive Load for Each Bus
Line
RST Pulse Width t
RST Rising to START Condition
Setup Time
t
HD, STA
t
SU, STA
t
SU, STO
t
HD, DAT
t
SU, DAT
VD, DAT
SCL
t
BUF
LOW
HIGH
t
R
t
F
F,TX
t
SP
C
b
W
t
RST
1.3 µs
0.6 µs
0.6 µs
0.6 µs
(Note 3) 0.9 µs
100 ns
SCL low to SDA output valid 3.4 µs
1.3 µs
0.7 µs
(Notes 2, 4)
(Notes 2, 4)
(Notes 2, 4)
(Note 5) 50 ns
(Note 2) 400 pF
500 ns
20 +
0.1C
20 +
0.1C
20 +
0.1C
1µs
400 kHz
300 ns
b
300 ns
b
250 ns
b
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
4 _______________________________________________________________________________________
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
0
0.4
0.2
1.0
0.8
0.6
1.2
1.4
1.8
1.6
2.0
-40 -10 5-25 20 35 50 65 80 95 110 125
STANDBY CURRENT vs. TEMPERATURE
MAX7320 toc01
TEMPERATURE (°C)
STANDBY CURRENT (μA)
V+ = +3.3V
V+ = +2.5V
V+ = +5.0V
V+ = +1.71V
f
SCL
= 0kHz
0
20
10
40
30
50
60
-40 -10 5 20-25 35 50 65 80 95 110 125
SUPPLY CURRENT vs. TEMPERATURE
MAX7320 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (μA)
V+ = +3.3V
V+ = +1.71V
V+ = +2.5V
f
SCL
= 400kHz
V+ = +5.0V
OUTPUT VOLTAGE LOW
vs. TEMPERATURE
TEMPERATURE (°C)
OUTPUT VOLTAGE LOW (V)
MAX7320 toc03
-40 -25 -10 5 20 35 50 65 80 95 110 125
0
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
V+ = +3.3V
I
SINK
= 3mA
V+ = +5.0V
I
SINK
= 5mA
V+ = +2.5V
I
SINK
= 2mA
V+ = +1.71V
I
SINK
= 1mA
OUTPUT VOLTAGE HIGH
vs. TEMPERATURE
TEMPERATURE (°C)
OUTPUT VOLTAGE HIGH (V)
MAX7320 toc04
-40 -25 -10 5 20 35 50 65 80 95 110 125
0
1
2
3
4
5
6
V+ = +5.0V
I
SOURCE
= 5mA
V+ = +3.3V
I
SOURCE
= 3mA
V+ = +1.71V
I
SOURCE
= 1mA
V+ = +2.5V
I
SOURCE
= 2mA
Pin Description
PIN
QSOP TQFN
1, 3 15, 1 AD0, AD2
216 RST Reset Input, Active Low. Drive RST low to clear the 2-wire interface.
4–7, 9–12 2–5, 7–10 O0–O7 Output Ports. O0 to O7 are push-pull outputs.
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.
NAME FUNCTION
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).
Detailed Description
MAX7319–MAX7329 Family Comparison
The MAX7319–MAX7323 family consists of five pincompatible, 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 pincompatible, 16-port expanders that integrate the functions of the MAX7320 and one of either the MAX7319,
MAX7321, MAX7322, or MAX7323.
Functional Overview
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 I
2
C serial interface up to
400kHz. Note the MAX7320 offers a different range of I
2
C
slave addresses than the MAX7319, MAX7321,
MAX7322, and MAX7323 (these expanders use the
address range 0x60 to 0x6F).
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
_______________________________________________________________________________________ 5
Table 1. MAX7319–MAX7329 Family Comparison
2
C
I
PART
8-PORT EXPANDERS
MAX7319 110xxxx 8 Yes — —
MAX7320 101xxxx — — — 8
MAX7321 110xxxx Up to 8 — Up to 8 —
MAX7322 110xxxx 4 Yes — 4
SLAVE
ADDRESS
INPUTS
INPUT
INTERRUPT
MASK
OPENDRAIN
OUTPUTS
PUSH-
PULL
OUTPUTS
APPLICATION
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.
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.
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.
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
6 _______________________________________________________________________________________
Table 1. MAX7319–MAX7329 Family Comparison (continued)
Table 2. Read and Write Access to Eight-Port Expander Family
2
C
I
PART
MAX7323 110xxxx Up to 4 — Up to 4 4
SLAVE
ADDRESS
INPUTS
MAX7328
MAX7329
16-PORT EXPANDERS
MAX7324 8 Yes — 8 Software equivalent to a MAX7320 plus a MAX7321.
MAX7325 Up to 8 — Up to 8 8 Software equivalent to a MAX7320 plus a MAX7319.
MAX7326 4 Yes — 12 Software equivalent to a MAX7320 plus a MAX7322.
MAX7327
0100xxx
0111xxx
101xxxx
and
110xxxx
Up to 8 — Up to 8 —
Up to 4 — Up to 4 12 Software equivalent to a MAX7320 plus a MAX7323.
INPUT
INTERRUPT
MASK
OPENDRAIN
OUTPUTS
PUSH-
PULL
OUTPUTS
APPLICATION
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.
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
open-drain output to logic-high.
2
I
PART
MAX7319 110xxxx 8 Yes — —
MAX7320 101xxxx — — — 8
MAX7321 110xxxx Up to 8 — Up to 8 —
MAX7322 110xxxx 4 Yes — 4
MAX7323 110xxxx Up to 4 — Up to 4 4 <port outputs>
MAX7328 0100xxx Up to 8 — Up to 8 —
MAX7329 0111xxx Up to 8 — Up to 8 —
C SLAVE
ADDRESS
INPUTS
INTERRUPT
MASK
OPENDRAIN
OUTPUTS
PUSH-
PULL
OUTPUTS
2
C DATA WRITE I2C DATA READ
I
<I7–I0 interrupt
mask>
<O7–O0 port
outputs>
<P7–P0 port
outputs>
<O7, O6 outputs,
I5–I2 interrupt
mask, O1, O0
outputs>
<P7–P0 port
outputs>
<P7–P0 port
outputs>
<I7–I0 port inputs>
<I7–I0 transition flags>
<O7-O0 port inputs>
<P7–P0 port inputs>
<P7–P0 transition flags>
<O7, O6, I5–I2, O1, O0 port
inputs>
<0, 0, I5–I2 transition flags,
0, 0>
<O7, O6, P5–P2, O1, O0 port
inputs>
<0, 0, P5-P2 transition flags,
0, 0>
<P7–P0 port inputs>
<P7–P0 port inputs>
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
addresses (101xxxx) than the MAX7319, MAX7321,
MAX7322, and MAX7323 (110xxxx).
The MAX7320 slave address is determined on each I
2
C
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 powerup 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
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
_______________________________________________________________________________________ 7
Table 3. MAX7320 Address Map
PIN
CONNECTION
AD2 AD0 A6 A5 A4 A3 A2 A1 A0 O7 O6 O5 O4 O3 O2 O1 O0
SCLGND101000011110000
SCLV+101000111111111
SCLSCL101001011111111
SCLSDA101001111111111
SDAGND101010011110000
SDAV+101010111111111
SDASCL101011011111111
SDASDA101011111111111
GNDGND101100000000000
GND V+ 1 0 1100100001111
GNDSCL101101000001111
GNDSDA101101100001111
V+GND101110011110000
V+V+101110111111111
V+SCL101111011111111
V+SDA101111111111111
DEVICE ADDRESS OUTPUTS POWER-UP DEFAULT
MAX7320
logic-high power-up state, and a 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 I
2
C 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 trans-
fers to and from the MAX7320, and generates the SCL
clock that synchronizes the data transfer (Figure 1).
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).
I2C Port Expander with Eight Push-Pull Outputs
8 _______________________________________________________________________________________
Figure 1. 2-Wire Serial-Interface Timing Details
Figure 2. START and STOP Conditions
SDA
t
BUF
t
LOW
t
SU,DAT
t
t
HD,DAT
SU,STA
t
HD,STA
t
SU,STO
SCL
t
HD,STA
START CONDITION
t
HIGH
t
R
t
F
t
VD,DAT
REPEATED START CONDITION
STOP
CONDITION
SDA
SCL
SP
START
CONDITION
START
CONDITION
CONDITION
STOP
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 I
2
C 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 sta-
tus 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 I
2
C
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 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).
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
_______________________________________________________________________________________ 9
Figure 3. Bit Transfer
Figure 4. Acknowledge
SDA
SCL
DATA LINE STABLE;
DATA VALID
START
CONDITION
SCL
SDA BY
TRANSMITTER
SDA BY
RECEIVER
S
CHANGE OF DATA
ALLOWED
CLOCK PULSE
FOR ACKNOWLEDGMENT
12 89
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
10 ______________________________________________________________________________________
Figure 5. Slave Address
Figure 6. Reading the MAX7320
Figure 7. Writing to the MAX7320
SDA
MSB
SCL
S
SCL
S = START CONDITION
P = STOP CONDITION
0
PORT SNAPSHOT DATA
R/W
SHADED = SLAVE TRANSMISSION
N = NOT ACKNOWLEDGE
O7 O6 O5 O4
11 0 1 MAX7320 SLAVE ADDRESS
A D7 D6 D5 D4 D2 D1 D0D3
PORT SNAPSHOT TAKEN PORT SNAPSHOT TAKEN
LSB
O3 O2 O1 O0
DATA 1
N
ACK1A11A3A0A2 R/W
P
ACKNOWLEDGE
FROM MASTER
SCL
SDA
DATA OUT
FROM PORT
12345678
SLAVE ADDRESS
S0
START CONDITION R/W ACKNOWLEDGE
AAA
FROM SLAVE
DATA TO PORT DATA TO PORT
DATA 1 DATA 2
t
PPV
ACKNOWLEDGE
FROM SLAVE
t
PPV
ACKNOWLEDGE
FROM SLAVE
DATA 2 VALIDDATA 1 VALID
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
______________________________________________________________________________________ 11
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).
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.
Figure 8. Output Port Structure
Functional Block Diagram
SDA
AD0
AD2
SCL
RST
INPUT
FILTER
POWER-
ON RESET
V+
I2C
CONTROL
GND
O7
O6
O5
O4
OUTPUT
PORTS
MAX7320
O3
O2
O1
O0
V+V+
MAX7320
PORT
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
12 ______________________________________________________________________________________
Compatibility with MAX6965, MAX7315,
and MAX7316
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
Table 4. MAX7320, MAX6965, MAX7315,
and MAX7316 Pin Compatibility
Chip Information
PROCESS: BiCMOS
Connect EP to GND
MAX7320
O2
O7
O6
O5
O4
V+
+3.3V
μC
SCL
SDA
SCL
AD0
O1
O0
SDA
O3
GND
OUTPUT
OUTPUT
AD2
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
OUTPUT
RST
RST
47nF
Typical Application Circuit
PIN-PACKAGE PIN FUNCTION
16
QSOP16TQFN
MAX7320 MAX7315
MAX6965 AND
MAX7316
1 15 AD0 AD0 BLINK
216RST AD1 RST
3 1 AD2 AD2 AD0
TOP VIEW
SCL
12 10 9
11
13
SDA
14
V+
15
AD0
16
RST
*EXPOSED PAD. CONNECT TO GND.
AD0
RST
AD2
O0
O1
O2
O3
GND
MAX7320
*EP
13
2
AD2
TQFN
3mm x 3mm x 0.8mm
1
2
3
MAX7320
4
5
6
7
8
O0 N.C.
O7
O6
O5
8
O4
7
GND
6
O3
5
4
O1
O2
16
V+
15
SDA
14
SCL
13
N.C.
12
O7
O6
11
10
O5
9
O4
QSOP
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
______________________________________________________________________________________ 13
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
MARKING
E/2
D/2
D
0.10 C 0.08 C
E
AAAA
C
L
(NE - 1) X e
(ND - 1) X e
C
L
A
A2
A1
L
e
k
L
E2
C
L
e
PACKAGE OUTLINE
8, 12, 16L THIN QFN, 3x3x0.8mm
D2/2
D2
b
E2/2
0.10 M C A B
C
L
L
e
21-0136
12x16L QFN THIN.EPS
1
I
2
8L 3x3
PKG
REF. MIN.
MIN.
NOM. MAX.
0.70 0.75 0.80
A
b
0.25 0.30 0.35
D
2.90
3.00 3.10
E
2.90 3.00 3.10
e
0.65 BSC.
L
0.35
0.55 0.75
ND
NE
0
0.02
A1
A2
0.20 REF
0.25
k
NOTES:
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF T ERMINALS.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO
JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED
WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE.
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.20 mm AND 0.25 mm
FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS .
9. DRAWING CONFORMS TO JEDEC MO220 REVISION C.
10. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY.
11. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY.
12. WARPAGE NOT TO EXCEED 0.10mm.
12L 3x3
NOM. MAX. NOM.
0.70
0.75
0.20
0.25
2.90
3.00
2.90
3.00
0.50 BSC.
0.45
8
2
2
-
0.55
12N
0.05
0.0230.05
0
0.20 REF
-
0.25
3
-
0.80
0.30
3.10
3.10
0.65
-
16L 3x3
MIN. MAX.
0.70
0.75
0.80
0.20
0.25
0.30
2.90
3.00
3.10
2.90
3.00
0.50 BSC.
0.30
0.40
16
4
040.02
0.20 REF
-
0.25
EXPOSED PAD VARIATIONS
PKG.
CODES
TQ833-1 1.250.25 0.70 0.35 x 45° WEEC1.250.700.25
-
T1233-1
T1233-3
T1233-4
T1633-2 0.95
T1633F-3
T1633FH-3 0.65 0.80 0.95
T1633-4 0.95
T1633-5 0.95
3.10
0.50
0.05
D2
MIN.
NOM.
0.95
1.10
1.10
0.95
1.10
0.65
0.80
1.10 1.25 0.95 1.10
1.10
MAX.
1.25
1.25
1.251.10
1.25
0.95
1.25
E2
NOM.
MIN.
MAX.
1.10
0.95
1.25
0.95 1.10 0.35 x 45°1.25 WEED-10.95
1.100.95
1.10
1.25
0.95
0.80
0.95
0.65
0.95
0.65 0.80
1.25
1.10 1.25
0.95
PACKAGE OUTLINE
8, 12, 16L THIN QFN, 3x3x0.8mm
PIN ID
JEDEC
WEED-1
0.35 x 45°
WEED-11.25
0.35 x 45°
0.35 x 45°
WEED-2
0.225 x 45°
WEED-2
0.225 x 45°
WEED-2
0.35 x 45°
WEED-2
0.35 x 45° WEED-2
21-0136
2
I
2
MAX7320
I2C Port Expander with Eight Push-Pull Outputs
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
QSOP.EPS
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