PCF8574AT NXP Semiconductors, PCF8574AT Datasheet - Page 9

• Manufacturer Part Number: PCF8574AT
• Manufacturer: NXP Semiconductors

Specifications of PCF8574AT

• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Operating Temperature (max): 85C
• Package Type: SO
• Rad Hardened: No
• Lead Free Status / Rohs Status: Compliant

Philips Semiconductors
7
7.1
For addressing see Figs 10, 11 and 12.
Each of the PCF8574’s eight I/Os can be independently used as an input or output. Input data is transferred from the
port to the microcontroller by the READ mode (see Fig.12). Output data is transmitted to the port by the WRITE mode
(see Fig.11).
2002 Nov 22
handbook, full pagewidth
handbook, full pagewidth
Remote 8-bit I/O expander for I
FUNCTIONAL DESCRIPTION
Addressing
S
write pulse
data from
shift register
power-on
reset
read pulse
data to
shift register
0
1
a. PCF8574.
slave address
0
0
Fig.10 PCF8574 and PCF8574A slave addresses.
Fig.9 Simplified schematic diagram of each I/O.
A2
A1
D
C I
FF
S
A0
Q
2
0
C-bus
A
D
C I
FF
S
9
Q
S
0
1
100
A
b. PCF8574A.
1
slave address
1
A2
MBD977
A1
A0
P0 to P7
to interrupt
V DD
V SS
logic
0
Product specification
MBD973
A
PCF8574