MCP23009 Microchip Technology Inc., MCP23009 Datasheet - Page 22

• Manufacturer Part Number: MCP23009
• Description: 8-bit I/o Expander With Open-drain Outputs
• Manufacturer: Microchip Technology Inc.

MCP23009/MCP23S09
1.6.7
The GPPU register controls the pull-up resistors for the
port pins. If a bit is set the corresponding port pin is
internally pulled up with an internal resistor.
REGISTER 1-8:
FIGURE 1-10:
DS22121A-page 22
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-0
R/W-0
PU7
400
350
300
250
200
150
100
PULL-UP RESISTOR
CONFIGURATION REGISTER
50
0
PU7:PU0: Controls the internal pull-up resistors on each pin (when configured as an input or output)
<7:0>.
1 = Pull-up enabled.
0 = Pull-up disabled.
1.5
R/W-0
GPIO Pin Internal Pull-up Current vs V
PU6
GPPU – GPIO PULL-UP RESISTOR REGISTER
TYPICAL PERFORMANCE CURVE FOR THE INTERNAL PULL-UP RESISTORS
2
W = Writable bit
‘1’ = Bit is set
R/W-0
PU5
2.5
R/W-0
PU4
3
V
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
DD
3.5
R/W-0
PU3
(V)
T = +25°C
4
R/W-0
PU2
T = +85°C
4.5
© 2008 Microchip Technology Inc.
T = -40°C
x = Bit is unknown
DD
R/W-0
PU1
T = +125°C
5
R/W-0
5.5
PU0
bit 0