SC9244

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:1.0

2006.04.24

Http: www.silan.com.cn

Page 3 of 11

PIN CONFIGURATION

PIN DESCRIPTIONS

Pin no.

SOP24

SOP20

Pin name

I/O

Functions

1

1

OSCI

I

Oscillator input pin

2

2

OSCO

O

Oscillator output pin

3

3

GND

--

Ground

4~11

4~11

PB0~PB7

O

Key scan signal output pin

12

12

IROUT

O

Infrared transmitting output pin

15~16

--

PA0~PA1

I

Key scan signal input pin, when in SOP20 package, do not

have these two pins

17~20

14~17

PA2~PA5

I

Key scan signal input pin

22

18

--

Positive power supply

23~24

19~20

PA6~PA7

I

Key scan signal input pin

FUNCTION DESCRIPTIONS

1. OSCILLATOR CIRCUIT

There is a ceramic oscillator between OSCI and OSCO, and a 100pF capacitor whose capacitance is 455KHz

between two oscillator pins and GND. To reduce the power dissipation, the oscillator circuit will work when press

the key, or else it stops. It can generate 38KHz carrier by internal frequency division.

FIR=455KHz/12=37.92KHz

Duty=1/3