PCF8574; PCF8574A
NXP Semiconductors
Remote 8-bit I/O expander for I2C-bus with interrupt
24. Contents
1
General description. . . . . . . . . . . . . . . . . . . . . . 1
18.3
18.4
Manual soldering . . . . . . . . . . . . . . . . . . . . . . 24
Package related soldering information. . . . . . 25
2
Features and benefits . . . . . . . . . . . . . . . . . . . . 1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ordering information. . . . . . . . . . . . . . . . . . . . . 2
Ordering options. . . . . . . . . . . . . . . . . . . . . . . . 2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
19
20
21
Soldering: PCB footprints . . . . . . . . . . . . . . . 26
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 28
Revision history . . . . . . . . . . . . . . . . . . . . . . . 29
3
4
4.1
5
22
Legal information . . . . . . . . . . . . . . . . . . . . . . 31
Data sheet status . . . . . . . . . . . . . . . . . . . . . . 31
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 32
22.1
22.2
22.3
22.4
6
6.1
6.2
Pinning information. . . . . . . . . . . . . . . . . . . . . . 4
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
7
Functional description . . . . . . . . . . . . . . . . . . . 5
Device address. . . . . . . . . . . . . . . . . . . . . . . . . 5
Address maps. . . . . . . . . . . . . . . . . . . . . . . . . . 5
23
24
Contact information . . . . . . . . . . . . . . . . . . . . 32
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.1
7.1.1
8
I/O programming . . . . . . . . . . . . . . . . . . . . . . . . 6
Quasi-bidirectional I/Os . . . . . . . . . . . . . . . . . . 6
Writing to the port (Output mode) . . . . . . . . . . . 8
Reading from a port (Input mode) . . . . . . . . . . 9
Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 9
Interrupt output (INT) . . . . . . . . . . . . . . . . . . . 10
8.1
8.2
8.3
8.4
8.5
9
Characteristics of the I2C-bus . . . . . . . . . . . . 11
Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
START and STOP conditions . . . . . . . . . . . . . 11
System configuration . . . . . . . . . . . . . . . . . . . 11
Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1
9.1.1
9.2
9.3
10
10.1
10.2
Application design-in information . . . . . . . . . 13
Bidirectional I/O expander applications . . . . . 13
How to read and write to I/O expander
(example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
High current-drive load applications . . . . . . . . 14
Migration path. . . . . . . . . . . . . . . . . . . . . . . . . 14
10.3
10.4
11
12
13
14
15
16
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 15
Thermal characteristics . . . . . . . . . . . . . . . . . 15
Static characteristics. . . . . . . . . . . . . . . . . . . . 16
Dynamic characteristics . . . . . . . . . . . . . . . . . 17
Package outline . . . . . . . . . . . . . . . . . . . . . . . . 19
Handling information. . . . . . . . . . . . . . . . . . . . 22
17
Soldering of SMD packages . . . . . . . . . . . . . . 22
Introduction to soldering . . . . . . . . . . . . . . . . . 22
Wave and reflow soldering . . . . . . . . . . . . . . . 22
Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 22
Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . 23
17.1
17.2
17.3
17.4
18
18.1
Soldering of through-hole mount packages . 24
Introduction to soldering through-hole mount
packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Soldering by dipping or by solder wave . . . . . 24
18.2
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2013.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 27 May 2013
Document identifier: PCF8574_PCF8574A
NXP [ NXP ]
