Silan

Semiconductors

SC5272

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 1.0

2000.12.31

5

The Synchronous bit waveform is 4 bits long with 1/8 bit width pulse. Please refer to the diagram below:

1/8 bit width=4a

4 bit width=128a

Note: 1bit =32a

Code word

A group of Code Bits is called a Code Word. A Code Word consists of 12 AD bits followed by one Sync. Bit. The

12 AD bits are interpreted as either address or data bits depending on the SC5272 version used. Please refer to

the diagram below:

A0

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

SYNC

Single Resistor Oscillator

The Build-in oscillator circuitry of SC5272 allows a precision oscillator to be constructed by connecting an

external resistor between OSC1 and OSC2 pins. For SC5272 to decode correctly the received waveform, the

oscillator frequency of SC5272 must be 2.5 ~8 times that of transmitting SC5262. It is a good practice to center the

SC5272 oscillator frequency in the window to gain best window margin at both sides. The typical oscillator

frequency with various resistor values for both SC5262 and SC5272 are shown below:

0

3

6

9

12

15

1

10

100

Supply Voltage (V)

Encoder OSC Frequency

0

3

6

9

12

15

1

10

1000

Supply Voltage (V)

Decoder OSC Frequency

100

R=510k

R=1M

R=3.3M

R=4.7M

R=100k

R=240k

R=510k

R=1M

R=2M

R=2M

Suggested Oscillator resistor values are shown below:

4.7M

820k

3.3M

1.2M

680k

200k

SC5262

SC5272