Philips Semiconductors

Product specification

PCA8550

2

1998 Sep 29

853-2015 20105

FEATURES

Pentium II is a registered trademark of Intel Corporation

DESCRIPTION

either a 4-bit input or data from a non-volatile register and drive this

value onto the output pins. One additional non-multiplexed register

output is also provided. The non-multiplexed output is latched to

register. A write protect input is provided to enable/disable the ability

to write to the non-volatile register. An ‘‘override” input feature forces

all outputs to logic 0.

PIN CONFIGURATION

I

OVERRIDE#

MUX_IN A

GND

WP

NON_MUXED_OUT

1

16

2

15

3

14

4

13

5

12

6

11

7

10

8

9

MUX_IN B

MUX_IN C

MUX_IN D

MUX_SELECT

MUX_OUT A

MUX_OUT B

MUX_OUT C

MUX_OUT D

SW00216

ORDERING INFORMATION

PACKAGES

TEMPERATURE RANGE

OUTSIDE NORTH AMERICA

NORTH AMERICA

DRAWING NUMBER

16-Pin Plastic SO

0

°C to +70°C

PCA8550D

PCA8550D

SOT109-1

16-Pin Plastic SSOP

0

°C to +70°C

PCA8550DB

PCA8550DB

SOT338-1

16-Pin Plastic TSSOP

0

°C to +70°C

PCA8550PW

PCA8550PW DH

SOT403-1

FUNCTIONAL DESCRIPTION

When the MUX_SELECT signal is logic 0, the multiplexer will select

the data from the non-volatile register to drive on the MUX_OUT

pins. When the MUX_SELECT signal is logic 1, the multiplexer will

select the MUX_IN lines to drive on the MUX_OUT pins. The

MUX_SELECT signal is also used to latch the NON_MUXED_OUT

signal which outputs data from the non-volatile register. The

NON_MUXED_OUT signal latch is transparent when MUX_SELECT

is in a logic 0 state, and will latch data when MUX_SELECT is in a

logic 1 state. When the active-LOW OVERRIDE# signal is set to

logic 0 and the MUX_SELECT signal is at a logic 0, all outputs will

be driven to logic 0. This information is summarized in Table 1.

The write protect (WP) input is used to control the ability to write the

contents of the 5-bit non-volatile register. If the WP signal is logic 0,

register. If the WP signal is logic 1, data will not be allowed to be

written into the non-volatile register.

The factory default for the contents of the non-volatile register are all

bus (described in the next section).

The OVERRIDE#, WP, MUX_IN, and MUX_SELECT signals have

internal pullup resistors. See the DC and AC Characteristics for

hysteresis and signal spike suppression figures.