MAXIM MAX7301 Technical data
General Description
The MAX7301 compact, serial-interfaced I/O expander
(or general-purpose I/O (GPIO) peripheral) provides
microprocessors with up to 28 ports. Each port is individually user configurable to either a logic input or logic
output.
Each port can be configured either as a push-pull logic
output capable of sinking 10mA and sourcing 4.5mA,
or a Schmitt logic input with optional internal pullup.
Seven ports feature configurable transition detection
logic, which generates an interrupt upon change of port
logic level. The MAX7301 is controlled through an
SPI™-compatible 4-wire serial interface.
The MAX7301AAX and MAX7301ATL have 28 ports and
are available in 36-pin SSOP and 40-pin TQFN packages,
respectively. The MAX7301AAI has 20 ports and is available in a 28-pin SSOP package.
For a 2-wire I
2
C-interfaced version, refer to the
MAX7300 data sheet.
For a pin-compatible port expander with additional
24mA constant-current LED drive capability, refer to the
MAX6957 data sheet.
Applications
White Goods
Automotive
Gaming Machines
Industrial Controllerss
System Monitoring
Features
♦ High-Speed 26MHz SPI-/QSPI-™/MICROWIRE™-
Compatible Serial Interface
♦ 2.5V to 5.5V Operation
♦ -40°C to +125°C Temperature Range
♦ 20 or 28 I/O Ports, Each Configurable as
Push-Pull Logic Output
Schmitt Logic Input
Schmitt Logic Input with Internal Pullup
♦ 11µA (max) Shutdown Current
♦ Logic Transition Detection for Seven I/O Ports
MAX7301
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
________________________________________________________________ Maxim Integrated Products 1
19-2438; Rev 6; 4/06
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.
Pin Configurations appear at end of data sheet.
Ordering Information
PART
PIN-
PKG
CODE
MAX7301AAI+
28 SSOP A28-1
MAX7301AAX+
36 SSOP A36-4
MAX7301ATL+
40 TQFN
T4066- 5
P5
P4
P7
P8
P6
P10
P9
P12
P13
P11
P15
P14
P17
P18
P16
P20
P19
P22
P23
P21
36
2
3
33
4
34
35
29
27
31
24
25
22
21
23
V+
GND
GND
SCLK
DIN
DOUT
P30
P29
P31
P27
P28
P25
P24
P26
32
30
26
5
7
9
28
6
8
11
10
12
14
15
13
17
16
19
20
18
CS
MAX7301
3V
SSOP
CHIP SELECT
DATA IN
CLOCK IN
DATA OUT
I/O 4
I/O 5
I/O 6
I/O 7
I/O 8
I/O 9
I/O 10
I/O 11
I/O 12
I/O 13
I/O 14
I/O 15
I/O 16
I/O 17
I/O 18
I/O 19
I/O 20
I/O 21
I/O 22
I/O 23
I/O 24
I/O 25
I/O 26
I/O 27
I/O 28
I/O 29
I/O 30
I/O 31
47nF
1
ISET
39kΩ
Typical Operating Circuit
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
+Denotes lead-free package.
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PACKAGE
MAX7301
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
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.
(Voltage with respect to GND.)
V+ .............................................................................-0.3V to +6V
All Other Pins................................................-0.3V to (V+ + 0.3V)
P4–P31 Current ................................................................±30mA
GND Current .....................................................................800mA
Continuous Power Dissipation (T
A
= +70°C)
28-Pin SSOP (derate 9.5mW/°C above +70°C) ...........762mW
36-Pin SSOP (derate 11.8mW/°C above +70°C) .........941mW
40-Pin TQFN (derate 26.3mW/°C above +70°C) ....2963.0mW
Operating Temperature Range
(T
MIN
, T
MAX
) ..................................................-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
(Typical Operating Circuit, V+ = 2.5V to 5.5V, TA= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Supply Voltage V+
5.5 V
TA = +25°C 5.5 8
10Shutdown Supply Current I
SHDN
All digital inputs at V+
or GND
T
A
= T
MIN
to T
MAX
11
µA
TA = +25°C
230
250
Operating Supply Current
(Output High)
I
GPOH
All ports programmed
as outputs high, no
load, all other inputs
at V+ or GND
T
A
= T
MIN
to T
MAX
270
µA
TA = +25°C
210
230
Operating Supply Current
(Output Low)
I
GPOL
All ports programmed
as outputs low, no
load, all other inputs
at V+ or GND
T
A
= T
MIN
to T
MAX
240
µA
TA = +25°C
135
140
Operating Supply Current
(Input)
I
GPI
All ports programmed
as inputs without
pullup, ports, and all
other inputs at V+ or
GND
T
A
= T
MIN
to T
MAX
145
µA
INPUTS AND OUTPUTS
Logic High Input Voltage
Port Inputs
V
IH
0.7 ✕
V+
V
Logic Low Input Voltage
Port Inputs
V
IL
0.3 ✕
V+
V
Input Leakage Current IIH, I
IL
GPIO inputs without pullup,
VPORT = V+ to GND
±1
nA
V+ = 2.5V 12 19 30
GPIO Input Internal Pullup to V+
I
PU
V+ = 5.5V 80
180
µA
Hysteresis Voltage GPIO Inputs
∆V
I
0.3 V
GPIO outputs, I
SOURCE
= 2mA,
T
A
= -40°C to +85°C
V+ -
0.7
Output High Voltage V
OH
GPIO outputs, I
SOURCE
= 1mA,
T
A
= T
MIN
to T
MAX
(Note 2)
V+ -
0.7
V
2.5
TA = - 40° C to + 85°C
180
TA = - 40° C to + 85°C
TA = - 40° C to + 85°C
TA = - 40° C to + 85°C
170
110
-100
120
+100
MAX7301
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
_______________________________________________________________________________________ 3
Note 1: All parameters tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Guaranteed by design.
ELECTRICAL CHARACTERISTICS (continued)
(Typical Operating Circuit, V+ = 2.5V to 5.5V, TA= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
UNITS
Port Sink Current I
OL
V
PORT
= 0.6V 2 10 18 mA
Output Short-Circuit Current I
OLSC
Port configured output low, shorted to V+
11
mA
V+ ≤ 3.3V 1.6
Input High-Voltage SCLK, DIN,
CS
V
IH
V+ > 3.3V 2
V
Input Low-Voltage SCLK, DIN,
CS
V
IL
0.6 V
Input Leakage Current SCLK,
DIN, CS
I
IH
, I
IL
-50 +50 nA
Output High-Voltage DOUT V
OH
I
SOURCE
= 1.6mA
V+ -
0.5
V
Output Low-Voltage DOUT V
OL
I
SINK
= 1.6mA 0.4 V
TIMING CHARACTERISTICS (Figure 3)
(V+ = 2.5V to 5.5V, TA= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
UNITS
CLK Clock Period t
CP
ns
CLK Pulse Width High t
CH
19 ns
CLK Pulse Width Low t
CL
19 ns
CS Fall to SCLK Rise Setup Time
t
CSS
9.5 ns
CLK Rise to CS Rise Hold Time
t
CSH
0ns
DIN Setup Time t
DS
9.5 ns
DIN Hold Time t
DH
0ns
Output Data Propagation Delay
t
DO
C
LOAD
= 25pF 21 ns
Minimum CS Pulse High t
CSW
19 ns
SYMBOL
SYMBOL
MIN TYP MAX
2.75
MIN TYP MAX
38.4
20.00
MAX7301
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
4 _______________________________________________________________________________________
OPERATING SUPPLY CURRENT
vs. TEMPERATURE
MAX7301 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
97.570.042.515.0-12.5
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0.40
0
-40.0 125.0
V+ = 2.5V TO 5.5V
NO LOAD
ALL PORTS
OUTPUT (1)
ALL PORTS
OUTPUT (0)
ALL PORTS INPUT HIGH
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX7301 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
97.570.042.515.0-12.5
4
5
6
7
8
3
-40.0 125.0
V+ = 5.5V
V+ = 3.3V
V+ = 2.5V
OPERATING SUPPLY CURRENT
vs. V+ (OUTPUTS UNLOADED)
MAX7301 toc03
V+ (V)
SUPPLY CURRRENT (mA)
5.04.54.03.53.02.5
1.0
0.1
2.0 5.5
ALL PORTS OUTPUT (1)
ALL PORTS OUTPUT (0)
ALL PORTS INPUT
(PULLUPS DISABLED)
GPO SINK CURRENT vs. TEMPERATURE
(OUTPUT = 0)
MAX7301 toc04
TEMPERATURE (°C)
PORT SINK CURRENT (mA)
97.570.0-12.5 15.0 42.5
4
6
8
10
12
14
16
18
2
-40.0 125.0
V+ = 2.5V TO 5.5V, V
PORT
= 0.6V
GPO SHORT-CIRCUIT CURRENT
vs. TEMPERATURE
MAX7301 toc07
TEMPERATURE (°C)
PORT CURRENT (mA)
97.570.042.515.0-12.5
10
100
1
-40.0 125.0
GPO = 0, PORT
SHORTED TO V+
GPO = 1, PORT
SHORTED TO GND
GPO SOURCE CURRENT vs. TEMPERATURE
(OUTPUT = 1)
MAX7301 toc05
TEMPERATURE (°C)
PORT SOURCE CURRENT (mA)
97.570.042.515.0-12.5
3
4
5
6
7
8
9
2
-40.0 125.0
V
PORT
= 1.4
V+ = 5.5V
V+ = 3.3V
V+ = 2.5V
GPI PULLUP CURRENT
vs. TEMPERATURE
MAX7301 toc06
TEMPERATURE (°C)
PULLUP CURRENT (µA)
97.570.042.515.0-12.5
100
1000
10
-40.0 125.0
V+ = 5.5V
V+ = 3.3V
V+ = 2.5V
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
Detailed Description
The MAX7301 GPIO peripheral provides up to 28 I/O
ports, P4 to P31, controlled through an SPI-compatible
serial interface. The ports can be configured to any
combination of logic inputs and logic outputs, and
default to logic inputs on power-up.
Figure 1 is the MAX7301 functional diagram. Any I/O
port can be configured as a push-pull output (sinking
10mA, sourcing 4.5mA), or a Schmitt-trigger logic
input. Each input has an individually selectable internal
pullup resistor. Additionally, transition detection allows
seven ports (P24 through P30) to be monitored in any
maskable combination for changes in their logic status.
A detected transition is flagged through an interrupt pin
(port P31).
The port configuration registers set the 28 ports, P4 to
P31, individually as GPIO. A pair of bits in registers
0x09 through 0x0F sets each port’s configuration
(Tables 1 and 2).
The 36-pin MAX7301AAX and 40-pin MAX7301ATL
have 28 ports, P4 to P31. The 28-pin MAX7301AAI is
offered in 20 ports, P12 to P31. The eight unused ports
should be configured as outputs on power-up by writing 0x55 to registers 0x09 and 0x0A. If this is not done,
the eight unused ports remain as floating inputs and
quiescent supply current rises, although there is no
damage to the part.
Register Control of I/O Ports
Across Multiple Drivers
The MAX7301 offers 20 or 28 I/O ports, depending on
package choice.
Two addressing methods are available. Any single port
(bit) can be written (set/cleared) at once; or, any
sequence of eight ports can be written (set/cleared) in
any combination at once. There are no boundaries; it is
equally acceptable to write P0 through P7, P1 through
P8, or P31 through P38 (P32 through P38 are nonexistent, so the instructions to these bits are ignored).
Shutdown
When the MAX7301 is in shutdown mode, all ports are
forced to inputs (which can be read), and the pullup
current sources are turned off. Data in the port and
control registers remain unaltered so port configuration
and output levels are restored when the MAX7301 is
taken out of shutdown. The display driver can still be
programmed while in shutdown mode. For minimum
supply current in shutdown mode, logic inputs should
be at GND or V+ potential. Shutdown mode is exited by
setting the S bit in the configuration register (Table 6).
MAX7301
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
_______________________________________________________________________________________ 5
PIN
36 SSOP
TQFN
NAME FUNCTION
1136 ISET
Bias Current Setting. Connect I
SET
to GND through a resistor (R
ISET
) value of
39kΩ to 120kΩ.
2, 3 2, 3
GND Ground
4440 DOUT 4-Wire Interface Serial Data Output Port
— 5–24 —
I/O Ports. P12 to P31 can be configured as push-pull outputs, CMOS logic
inputs, or CMOS logic inputs with weak pullup resistor.
5–32 —
1–10,
12–19,
21–30
I/O Ports. P4 to P31 can be configured as push-pull outputs, CMOS logic
inputs, or CMOS logic inputs with weak pullup resistor.
——
N.C. No Connection. Not internally connected.
33 25 32 SCLK 4-Wire Interface Serial Clock Input Port
34 26 33 DIN 4-Wire Interface Serial Data Input Port
35 27 34 CS 4-Wire Interface Chip-Select Input, Active Low
36 28 35 V+
Positive Supply Voltage. Bypass V+ to GND with a minimum 0.047µF
——PAD
Exposed
Pad
Exposed Pad on Package Underside. Connect to GND.
Pin Description
28 SSOP
37, 38, 39
P12–P31
P4–P31
11, 20, 31
MAX7301
Serial Interface
The MAX7301 communicates through an SPI-compatible 4-wire serial interface. The interface has three
inputs, Clock (SCLK), Chip Select (CS), and Data In
(DIN), and one output, Data Out (DOUT). CS must be
low to clock data into or out of the device, and DIN
must be stable when sampled on the rising edge of
SCLK. DOUT provides a copy of the bit that was input
15.5 clocks earlier, or upon a query it outputs internal
register data, and is stable on the rising edge of SCLK.
Note that the SPI protocol expects DOUT to be high
impedance when the MAX7301 is not being
accessed; DOUT on the MAX7301 is never high
impedance. See www.maxim-ic.com/an 1879 for
ways to convert DOUT to tri-state, if required.
SCLK and DIN may be used to transmit data to other
peripherals, so the MAX7301 ignores all activity on
SCLK and DIN except between the fall and subsequent
rise of CS.
Control and Operation Using the
4-Wire Interface
Controlling the MAX7301 requires sending a 16-bit
word. The first byte, D15 through D8, is the command
address (Table 3), and the second byte, D7 through
D0, is the data byte (Table 4 through Table 8).
Connecting Multiple MAX7301s
to the 4-Wire Bus
Multiple MAX7301s may be daisy-chained by connecting the DOUT of one device to the DIN of the next, and
driving SCLK and CS lines in parallel (Figure 3). Data at
DIN propagates through the internal shift registers and
appears at DOUT 15.5 clock cycles later, clocked out
on the falling edge of SCLK. When sending commands
to multiple MAX7301s, all devices are accessed at the
same time. An access requires (16 ✕n) clock cycles,
where n is the number of MAX7301s connected together. To update just one device in a daisy-chain, the user
can send the No-Op command (0x00) to the others.
Writing Device Registers
The MAX7301 contains a 16-bit shift register into which
DIN data are clocked on the rising edge of SCLK, when
CS is low. When CS is high, transitions on SCLK have
no effect. When CS goes high, the 16 bits in the Shift
register are parallel loaded into a 16-bit latch. The 16
bits in the latch are then decoded and executed.
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
6 _______________________________________________________________________________________
Table 1. Port Configuration Map
REGISTER DATA
REGISTER
ADDRESS
CODE (HEX)
D0
Port Configuration for P7, P6, P5, P4 0x09 P7 P6 P5 P4
Port Configuration for P11, P10, P9, P8 0x0A P11 P10 P9 P8
Port Configuration for P15, P14, P13, P12 0x0B P15 P14 P13 P12
Port Configuration for P19, P18, P17, P16 0x0C P19 P18 P17 P16
Port Configuration for P23, P22, P21, P20 0x0D P23 P22 P21 P20
Port Configuration for P27, P26, P25, P24 0x0E P27 P26 P25 P24
Port Configuration for P31, P30, P29, P28 0x0F P31 P30 P29 P28
Table 2. Port Configuration Matrix
PORT
CONFIGURATION
BIT PAIR
MODE
FUNCTION
PORT
REGISTER
(0x20–0x5F)
(0xA0–0xDF)
PIN BEHAVIOR
ADDRESS
)
LOWER
DO NOT USE THIS SETTING
00
Active-low logic output
Output
GPIO Output
Active-high logic output
01
Input
GPIO Input
Without Pullup
Schmitt logic input
10
Input
Register bit =
Schmitt logic input with pullup
11
D7 D6 D5 D4 D3 D2 D1
CODE (HEX
0x09 to 0x0F
Register bit = 0
Register bit = 1
0x09 to 0x0F
UPPER
0x09 to 0x0F
GPIO Input with Pullup
input logic level
0x09 to 0x0F
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