1999 Jun 15

2

Philips Semiconductors

Product specification

Infrared remote control transmitter RC5

PCA8521

FEATURES

• RC5 protocol

• Maximum of:

– 56 keys (20-pin version)

– 30 keys (16-pin version).

• Option of multi-system or single system transmitter

– Multi-system: maximum 8 systems, selection by key

– Single system: maximum 8 different systems per IC,

selection by jumper wire or switch.

• Power-down and key wake-up

• High output current (≤ 45 mA)

• Oscillator frequency of 432 kHz or 4 MHz

• Multiple key protection

• Option of 25% or 33% duty factor

• Contained in DIP16, SO16, DIP20 or SO20 packages.

GENERAL DESCRIPTION

The PCA8521 can be used in infrared remote control

transmitters. It generates output pulses, in accordance

with the RC5 protocol, when a key is pressed. The IC does

not contain a software programmable processor.

However, it does contain a ROM in which the codes that

have to be transmitted are stored. An example of an

application diagram using a 20-pin IC is illustrated in Fig.7.

The oscillator frequency may be optionally chosen as

432 kHz or 4 MHz. For 432 kHz additional external

capacitors must be connected. The capacitors for a 4 MHz

oscillator is integrated. When a key in the key-matrix is

pressed a drive line will be connected to a sense line. This

causes the oscillator to start and a corresponding code will

be generated conforming to the RC5 protocol.

Seven drive lines (DR0 to DR6) and eight sense lines

(SN0 to SN7) may be connected via the key matrix to scan

the keys (see Fig.1).

When two or more keys are activated simultaneously no

transmission will take place.

ORDERING INFORMATION

TYPE

NUMBER

PACKAGE

NAME

DESCRIPTION

VERSION

PCA8521FP

DIP16

plastic dual in-line package; 16 leads (300 mil)

SOT38-4

PCA8521FT

SO16

plastic small outline package; 16 leads; body width 7.5 mm

SOT162-1

PCA8521BP

DIP20

plastic dual in-line package; 20 leads (300 mil)

SOT146-1

PCA8521BT

SO20

plastic small outline package; 20 leads; body width 7.5 mm

SOT163-1