Silan

Semiconductors

SC50462

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 2.1

2002-02-28

4

2. OSCILLATING CIRCUIT

An oscillator circuit may be constructed by using a 480kHz or 455kHz Crystal Resonator and two capacitors.

Please refer to the following diagram. The carrier frequency transmitted is 40kHz or 37.9kHz.Unless any legal key

input is activated, the oscillation is automatically stopped. Thus ,power consumption is considerably reduced.

OSCI

OSCO

480kHz/

455kHz

200pF

200pF

SC50462

2

3

3. KEY INPUT

A total of 64 keys may be connected by Input Pins(I1~I8) and Output Pins(S1~S8) to form an 8x8 Key Matrix.

Double key operation is possible for only one of the keys—SW25~SW28 in combination with any one of the keys –

SW11~SW13. Any other key combination are regards as illegal and will not generate any activity. Thus, only the

following key combinations may be used for the doubled key operation:

S1

S2

S3

S4

S5

S6

S7

S8

I8

I7

I6

I5

I4

I3

I2

I1

SW11

SW12

SW13

SW25

SW26

SW27

SW28

SW25 and SW11

SW25 and SW12

SW25 and SW13

SW26 and SW11

SW26 and SW12

SW26 and SW13

SW27 and SW11

SW27 and SW12

SW27 and SW13

SW28 and SW11

SW28 and SW12

SW28 and SW13

Note:

SC50462 permits two keys

function but only “

” key are

allowed.

When you push one key of

SW11/12/13, you can push with

another key of SW25/26/27/28.

Otherwise, other conditions are

illegal.