PCF8574 datasheet(8/24 Pages) PHILIPS

Teilenummer	PCF8574

Bauteilbeschribung	Remote 8-bit I/O expander for I2C-bus

PDF	24 Pages

Scroll/Zoom	100%

Hersteller	PHILIPS [NXP Semiconductors]

Direct Link	http://www.nxp.com

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8 / 24 page

1997 Apr 02

Philips Semiconductors

Product speciﬁcation

Remote 8-bit I/O expander for I2C-bus

PCF8574

FUNCTIONAL DESCRIPTION

7.1

Addressing

For addressing see Figs 9, 10 and 11.

Fig.8 Simplified schematic diagram of each I/O.

handbook, full pagewidth

MBD977

100

µA

to interrupt

logic

VSS

P0 to P7

VDD

write pulse

data from

shift register

power-on

reset

read pulse

data to

shift register

Fig.9 PCF8574 and PCF8574A slave addresses.

handbook, full pagewidth

MBD973

slave address

(a) PCF8574.

(b) PCF8574A.

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.11). Output data is transmitted to the port by the

WRITE mode (see Fig.10).

PCF8574 Datenblatt(PDF) 8 Page - NXP Semiconductors