Silan

Semiconductors

SC9148B

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

Rev: 2.1

2002.09.10.

3

FUNCTIONAL DESCRIPTION

1. OSCILLATION CIRCUIT

As the self-bias type amplifier by means of CMOS inverter has been housed, the oscillation circuit can be

constructed when LC or ceramic resonater is connected.

When oscillation frequency is set at 455kHz, carrier wave of transmitting signal is set at 38kHz, oscillation of the

oscillation circuit is kept stopped unless the keys are operated, thus reducing power consumption.

2

3

C1

C2

2

3

C1

C2

C1=C2=50~150pF

2. KEY INPUT

18 keys can be connected by key input K1~K6 and 6

×3 matrix by means of timing signal T1~T3 .

Multiple keying is possible for the keys connected to T1 line up to sextet , and all key inputs are output . (Output

becomes continuous pulses .)

Between the timing signal lines , priority has been decided in order of T1, T2 , T3 . The keys connected to T2

and T3 lines have priority and input is made through more than 2 keys , single signal is preferentially output in

order of K1~K6 .

Further , the keys connected to T2 and T3 lines are for single and not second signal is transmitted unless input

is made again after the key is released once.

1

7

13

2

8

14

3

9

15

4

10

16

5

11

17

6

12

18

K1

K2

K4

K3

K5

K6

(H)

(S1)

(S2)

T3

T2

T1