MCP23009/MCP23S09
1.1 Pin Descriptions
TABLE 1-1: I2C™ PINOUT DESCRIPTION (MCP23009)
Pin
Name
Pin Number
16-lead 18-lead 20-lead
QFN PDIP/SOIC SSOP
Pin
Type
Standard Function
VDD
3
1
1
P Power
NC
2
2, 16-17 2, 10-11, — Not connected
18-19
SCL
4
3
3
I Serial clock input
SDA
5
4
4
I/O Serial data I/O
ADDR
6
5
5
I Hardware address pin allows up to eight slave devices on the
bus
RESET 7
6
INT
8
7
GP0
9
8
GP1
10
9
GP2
11
10
GP3
12
11
GP4
13
12
GP5
14
13
GP6
15
14
GP7
16
15
VSS
1
18
EP
17
—
6
I Hardware reset
7
O Interrupt output for port. Can be configured as active-high,
active-low or open-drain.
8
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
9
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
12
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
13
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
14
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
15
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
16
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
17
I/O Bidirectional I/O pin (5.5V tolerant inputs; open-drain outputs).
Can be enabled for interrupt on change and/or internal pull-up
resistor.
20
P Ground
—
— Exposed Thermal Pad (EP). Can be left floating or connected
to VSS.
DS20002121C-page 4
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