Philips pca8521 DATASHEETS

INTEGRATED CIRCUITS

DATA SH EET

PCA8521

Infrared remote control transmitter RC5

Product speciﬁcation Supersedes data of 1997 Jul 03 File under Integrated Circuits, IC02

1999 Jun 15

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.

ORDERING INFORMATION

TYPE

NUMBER

PCA8521FP DIP16 PCA8521FT SO16 PCA8521BP DIP20 PCA8521BT SO20

NAME DESCRIPTION VERSION

plastic dual in-line package; 16 leads (300 mil) plastic small outline package; 16 leads; body width 7.5 mm plastic dual in-line package; 20 leads (300 mil) plastic small outline package; 20 leads; body width 7.5 mm

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 ( (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.

PACKAGE

DR0 to DR6) and eight sense lines

SOT38-4 SOT162-1 SOT146-1 SOT163-1

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Philips Semiconductors Product speciﬁcation

Infrared remote control transmitter RC5 PCA8521

BLOCK DIAGRAM

handbook, full pagewidth

SN0 SN1 SN2 SN3 SN4 SN5 SN6 SN7 DR0 DR1 DR2 DR3 DR4 DR5 DR6

432 kHz or 4 MHz

XTAL1 XTAL2

OSCILLATOR

STOP

4 5 6 7 9 10 8 3 16 15 14 13 12 11 17

SCANNING

KEY

TIMING GENERATOR

AND

CONTROL

36 kHz

1K x 8

ROM

SHIFT REGISTER

PULSE

GENERATOR

OUTPUT

DRIVER

LOUT

PCA8521

MBH038

Fig.1 Block diagram (for DIP20 and SO20 packages).

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Philips Semiconductors Product speciﬁcation

Infrared remote control transmitter RC5 PCA8521

PINNING 16-pin dual in-line and small outline package

SYMBOL PIN DESCRIPTION

XTAL1 1 oscillator input XTAL2 2 oscillator output SN0 3 sense line 0 for key matrix SN1 4 sense line 1 for key matrix SN2 5 sense line 2 for key matrix SN3 6 sense line 3 for key matrix SN4 7 sense line 4 for key matrix SN5 8 sense line 5 for key matrix DR4 9 drive line 4 for key matrix

(active LOW)

DR3 10 drive line 3 for key matrix

(active LOW)

DR2 11 drive line 2 for key matrix

(active LOW)

DR1 12 drive line 1 for key matrix

(active LOW)

DR0 13 drive line 0 for key matrix

(active LOW)

14 ground LOUT 15 output signal (active LOW) V

16 power supply

handbook, halfpage

Fig.2 Pin configuration (DIP/SO16).

XTAL1 XTAL2

SN0 SN1 SN2 SN3 SN4 SN5

1 2 3 4 5 6 7 8

PCA8521

MBH032

LOUT

DR0

DR1 DR2

DR3

DR4

1999 Jun 15 4

Philips Semiconductors Product speciﬁcation

Infrared remote control transmitter RC5 PCA8521

20-pin dual in-line and small outline package

SYMBOL PIN DESCRIPTION

XTAL1 1 oscillator input XTAL2 2 oscillator output SN7 3 sense line 7 for key matrix SN0 4 sense line 0 for key matrix SN1 5 sense line 1 for key matrix SN2 6 sense line 2 for key matrix SN3 7 sense line 3 for key matrix SN6 8 sense line 6 for key matrix SN4 9 sense line 4 for key matrix SN5 10 sense line 5 for key matrix DR5 11 drive line 5 for key matrix

(active LOW)

DR4 12 drive line 4 for key matrix

(active LOW)

DR3 13 drive line 3 for key matrix

(active LOW)

DR2 14 drive line 2 for key matrix

(active LOW)

DR1 15 drive line 1 for key matrix

(active LOW)

DR0 16 drive line 0 for key matrix

(active LOW)

DR6 17 drive line 6 for key matrix

(active LOW)

18 ground LOUT 19 output signal (active LOW) V

20 power supply

handbook, halfpage

Fig.3 Pin configuration (DIP/SO20).

XTAL1 XTAL2

SN7 SN0 SN1 SN2 SN3 SN6 SN4 SN5

1 2 3 4 5 6 7 8 9

PCA8521

MBH033

LOUT V

DR6

DR0

DR1

DR2

DR3 DR4

DR5

1999 Jun 15 5

Philips Semiconductors Product speciﬁcation

Infrared remote control transmitter RC5 PCA8521

FUNCTIONAL DESCRIPTION

Key numbering for the matrix is given in Tables 1 and 2.

Table 1 Key numbering for 16-pin package

DRIVER

LINES

DR0012345 DR1 8 9 10 11 12 13 DR2 16 17 18 19 20 21 DR3 24 25 26 27 28 29 DR4 32 33 34 35 36 37

Table 2 Key numbering for 20-pin package

DRIVER

LINES

DR0 01234567 DR1 8 9 10 11 12 13 14 15 DR2 16 17 18 19 20 21 22 23 DR3 24 25 26 27 28 29 30 31 DR4 32 33 34 35 36 37 38 39 DR5 40 41 42 43 44 45 46 47 DR6 48 49 50 51 52 53 54 55

SN0 SN1 SN2 SN3 SN4 SN5

SN0 SN1 SN2 SN3 SN4 SN5 SN6 SN7

SENSE LINES

When the keys have been scanned the key-number of the activated key serves as the address of the ROM to obtain the required code-word. When a 16-pin IC is used the following sense lines and driver lines will not be connected; SN6, SN7, DR5 and DR6. Consequently, key numbers 6, 7, 14, 15, 22, 23, 30, 31, 38, 39 and 40 to 55 will not be addressed.

The ROM contains 8 banks of 64 code-words. Thus for each key a maximum of 8 different code-words may be generated. With multi-system use, 8 different systems (e.g. TV, VCR, tuner, CD etc.) may be selected. Apart from the system bits the command bits may also be different in different banks (true multi-function keys). Selection can be performed using the keys. For each key three bank select bits are present that determine which bank will be selected for the next key.

For each key an ‘inhibit’ bit is also present. When this bit is at logic 1 at an address in a given bank, and when the corresponding key is pressed (when this bank has been selected) no transmission will take place.

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A single system option is available however, whereby instead of keys a jumper wire and/or a switch may be used for bank selection. Using this option it is possible to program different transmitter models in one IC and select the required bank by means of a jumper wire. Instead of a jumper wire a side-switch may also be used to change the generated code temporarily (select different bank) to obtain multi-function keys. With this option the jumper wires or switch must be connected between sense line SN0 and one of the drive linesDR0toDR6 or ground. This means that SN0 cannot be used to connect keys and the maximum number of keys will be 25 keys for a 16-pin package and 49 keys for a 20-pin package.

It is not possible to use a combination of jumper wires and selection keys for bank selection in one unit.

The output of the ROM is loaded into a shift register that provides the input bits for the pulse generator. This pulse generator drives the output pin.

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