19-2438; Rev 6; 4/06
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
28-Port I/O Expander
General Description
Features
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 indi-
vidually user configurable to either a logic input or logic
output.
♦ High-Speed 26MHz SPI-/QSPI-™/MICROWIRE™-
Compatible Serial Interface
♦ 2.5V to 5.5V Operation
♦ -40°C to +125°C Temperature Range
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.
♦ 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
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 avail-
able in a 28-pin SSOP package.
Ordering Information
For a 2-wire I2C-interfaced version, refer to the
MAX7300 data sheet.
PIN-
PACKAGE
PKG
CODE
PART
TEMP RANGE
For a pin-compatible port expander with additional
24mA constant-current LED drive capability, refer to the
MAX6957 data sheet.
MAX7301AAI+
MAX7301AAX+
MAX7301ATL+
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
28 SSOP
36 SSOP
40 TQFN
A28-1
A36-4
T4066-5
+Denotes lead-free package.
Applications
Typical Operating Circuit
White Goods
3V
Automotive
36
32
30
28
26
V+
P4
P5
I/O 4
I/O 5
Gaming Machines
Industrial Controllerss
System Monitoring
47nF
3
2
GND
GND
P6
I/O 6
I/O 7
P7
5
39kΩ
P8
I/O 8
I/O 9
1
ISET
7
P9
9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
I/O 10
I/O 11
MAX7301
35
33
34
4
11
6
CHIP SELECT
CLOCK IN
DATA IN
CS
SCLK
DIN
I/O 12
I/O 13
8
10
12
13
14
15
16
17
18
19
20
DATA OUT
DOUT
I/O 14
I/O 15
31
29
27
25
24
P31
P30
P29
P28
P27
P26
P25
P24
I/O 16
I/O 17
I/O 18
I/O 19
I/O 20
I/O 21
23
22
21
I/O 22
I/O 23
SSOP
I/O 24
I/O 25
I/O 26
I/O 27
I/O 28
I/O 29
I/O 30
I/O 31
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Pin Configurations appear at end of data sheet.
________________________________________________________________ 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.