Philips PCF8575C Datasheet

INTEGRATED CIRCUITS

DATA SH EET

PCF8575C

Remote 16-bit I/O expander for

C-bus

Product speciﬁcation File under Integrated Circuits, IC12

1999 Aug 05

Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I2C-bus

CONTENTS

1 FEATURES 2 GENERAL DESCRIPTION 3 ORDERING INFORMATION 4 BLOCK DIAGRAM 5 PINNING 6 FUNCTIONAL DESCRIPTION

6.1 Quasi-bidirectional I/Os

6.2 Addressing

6.3 Reading from a port (input mode)

6.4 Writing to the port (output mode)

6.5 Interrupt 7 CHARACTERISTICS OF THE I2C-BUS

7.1 Bit transfer

7.2 START and STOP conditions

7.3 System configuration

7.4 Acknowledge 8 LIMITING VALUES 9 HANDLING 10 CHARACTERISTICS 11 I2C-BUS TIMING CHARACTERISTICS 12 DEVICE PROTECTION 13 PACKAGE OUTLINE 14 SOLDERING

14.1 Introduction to soldering surface mount packages

14.2 Reflow soldering

14.3 Wave soldering

14.4 Manual soldering

14.5 Suitability of surface mount IC packages for wave and reflow soldering methods

15 DEFINITIONS 16 LIFE SUPPORT APPLICATIONS 17 PURCHASE OF PHILIPS I2C COMPONENTS

PCF8575C

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Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I2C-bus

1 FEATURES

• Operating supply voltage from 4.5 to 5.5 V

• Low standby current consumption of 10 µA maximum

• I2C-bus to parallel port expander

• 400 kbits/s FAST I2C-bus

• Open-drain interrupt output

• 16-bit remote I/O port for the I2C-bus

• Compatible with most microcontrollers

• Latched outputs with high current drive capability for

directly driving LEDs

• Address by 3 hardware address pins for use of up to

8 devices

• SSOP24 package.

2 GENERAL DESCRIPTION

The device is a silicon CMOS circuit. It provides general purpose remote I/O expansion for most microcontroller families via the two-line bidirectional bus (I2C-bus).

PCF8575C

The deviceconsists of a 16-bit quasi-bidirectional port and an I2C-bus interface. The PCF8575C has a low current consumption and includes latched outputs with high current drive capability for directly driving LEDs. It also possesses an interruptline (INT) which can beconnected to the interrupt logic of the microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontrollerif thereis incoming dataon itsportswithout having to communicate via the I2C-bus. This means that the device is an I2C-bus slave transmitter/receiver.

Every data transmission fromthe PCF8575Cmust consist of an even number of bytes, the first byte will be referred to as P07 to P00 and the second byteas P17 to P10. The third will be referred to as P07 to P00 and so on.

3 ORDERING INFORMATION

TYPE

NUMBER

PCF8575CTS SSOP24 plastic shrink small outline package; 24 leads; body width 5.3 mm SOT340-1

NAME DESCRIPTION VERSION

PACKAGE

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Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I2C-bus

4 BLOCK DIAGRAM

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INT

A0 A1 A2

SCL

SDA

2 3

22 23

INPUT

FILTER

INTERRUPT

LOGIC

PCF8575C

I2C-BUS

CONTROL

SHIFT

LP FILTER

16 BITS

I/O

PORT

PCF8575C

P00 to P07

4 to 11

P10 to P17

13 to 20

WRITE pulse

DD SS

24 12

POWER-ON

RESET

V V

READ pulse

MGS630

Fig.1 Block diagram.

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Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I2C-bus

5 PINNING

SYMBOL PIN DESCRIPTION

INT 1 interrupt output (active LOW) A1 2 address input 1 A2 3 address input 2 P00 4 quasi-bidirectional I/O 00 P01 5 quasi-bidirectional I/O 01 P02 6 quasi-bidirectional I/O 02 P03 7 quasi-bidirectional I/O 03 P04 8 quasi-bidirectional I/O 04 P05 9 quasi-bidirectional I/O 05 P06 10 quasi-bidirectional I/O 06 P07 11 quasi-bidirectional I/O 07 V

P10 13 quasi-bidirectional I/O 10 P11 14 quasi-bidirectional I/O 11 P12 15 quasi-bidirectional I/O 12 P13 16 quasi-bidirectional I/O 13 P14 17 quasi-bidirectional I/O 14 P15 18 quasi-bidirectional I/O 15 P16 19 quasi-bidirectional I/O 16 P17 20 quasi-bidirectional I/O 17 A0 21 address input 0 SCL 22 serial clock line input SDA 23 serial data line input/output V

12 supply ground

24 supply voltage

handbook, halfpage

INT

A2 P00 P01 P02

1 2 3 4 5 6

24 23 22 21 20 19

PCF8575C

P03 P04 P05 P06 P07

7 8

9 10 11 12

18 17 16 15 14 13

MGS631

Fig.2 Pin configuration.

PCF8575C

SDA SCL A0 P17 P16 P15 P14 P13 P12 P11 P10

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Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I2C-bus

PCF8575C

6 FUNCTIONAL DESCRIPTION

6.1 Quasi-bidirectional I/Os

The16 ports (seeFig.3) areentirely independent andcan beused eitheras input oroutput ports.Input dataistransferred from the ports to the microcontroller in the READ mode (see Fig.6). Output data istransmitted to the portsin the WRITE mode (see Fig.5).

This quasi-bidirectional I/O can be used as an input or output without the use of a control signal for data direction. At power-on all the I/Os are in 3-state mode. The strong pull-up to VDD (I

) allows a fast rising edge into a heavily

OHt

loaded output. This strong pull-up turns on when the output is written HIGH, and is switched off by the negative edge of SCL. Afterthis short periodthe output isin 3-state mode.The I/O should bewritten HIGH beforebeing used asan input. After power-on as all the I/Os are set to 3-state all of them can be used as inputs. Any change in setting of the I/Os as either inputs or outputs can be donewith the write mode.Warning: If a HIGH is applied to an I/O whichhas been written earlier to LOW, a large current (IOL) will flow to VSS (see Chapter 10; note 3).

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write pulse

data from shift register

power-on reset

OHt

P00 to P07 P10 to 17

read pulse

data to shift register

to interrupt

MGS632

logic

Fig.3 Simplified schematic diagram of each I/O.

6.2 Addressing

Figures 4, 5 and 6 show the address and timing diagrams. Before any data is transmitted or received the master must sendthe addressof thereceivervia theSDA line.Thefirst bytetransmitted aftertheSTART conditioncarries theaddress of theslave deviceand theread/write bit. Theaddress ofthe slavedevice must notbe changedbetween theSTART and the STOP conditions. The PCF8575C acts as a slave receiver or a slave transmitter.

handbook, halfpage

S 0 1 0 0 A2 A1 A0 R/W A

slave address

MGL541

Fig.4 Byte containing the slave address and the R/W bits.

1999 Aug 05 6

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1999 Aug 05 7

SCL

12345678

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Integral multiples of two bytes

Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I

WRITE TO

PORT

DATA OUTPUT

FROM PORT

05 OUTPUT

VOLTAGE

05 PULL-UP

OUTPUT CURRENT

INT

slave address (PCF8575C)

S 0 1 0 0 A2 A1 A0 0 A P07 P06 P00 P17 P101

start condition R/W P05acknowledge

from slave

data to port 0 data to port 1

A ASDA

acknowledge from slave

OHt

acknowledge from slave

Data A0 and

B0 valid

MGS633

C-bus

PCF8575C

Fig.5 WRITE mode (output).

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1999 Aug 05 8

SCL

SDA

S 0 1 0 0 A2 A1 A0 1 A P07 P06 P05 P04

P03 P02 P01 P00 P17 P10

A A P07 P00 A P17 P10 1P

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Philips Semiconductors Product speciﬁcation

Remote 16-bit I/O expander for I

READ FROM PORT

DATA INTO PORT

INT

R/W acknowledge

from slave

acknowledge from receiver

P07 to P00 P17 to P10P07 to P00 P17 to P10 P07 to P00 P17 to P10

acknowledge from receiver

MGL543

non acknowledge from receiver

A LOW-to-HIGH transition of SDA, while SCL isHIGHisdefinedasthe STOP condition (P).Transferofdatacanbe stopped at any moment by a STOPcondition.Whenthisoccurs, data present at the latest acknowledge phase is valid (output mode). Input data is lost.

Fig.6 READ mode (input).

C-bus

PCF8575C

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