Tel: 886-2-66296288

Fax: 886-2-29174598

URL: http://www.princeton.com.tw

PT2262 V3.8

- 6 -

September, 2008

Remote Control Encoder

PT2262

CODE FRAME

A Code Frame consists of four (4) continuous Code Words. When PT2262 detects “0” on the /TE

(meaning, the /TE is active “low”), it outputs a Code Frame at DOUT. If /TE is still active at the time the

Code Frame transmission ends, T2262 outputs another Code Frame. It should be noted that the Code

Frame is synthesized at the time of transmission.

/TE

DO UT

o n e fr ame ( = 4 w o r d)

o ne fr ame

o n e fr a me

SIGNAL RESISTOR OSCILLATOR

The built–in oscillator circuitry of PT2262 allows a precision oscillator to be constructed by connecting

an external resistor between OSC1 and OSC2 pins. For PT2272 to decode correctly the received

waveform, the oscillator frequency of PT2272 must be 2.5 ~ 8 times that of transmitting PT2262. The

typical oscillator frequency with various resistor values for both PT2262 and PT2272 are shown below:

Encoder OSC Frequency

Decoder OSC Frequency

100

10

1

(KHz)

3

6

9

12

15

Voltage(V)

R = 510 K

R = 1 M

R = 2 M

R = 3.3 M

R = 4.7 M

1000

100

10

(KHz)

3

6

9

12

15

Voltage(V)

R = 100 K

R = 240 K

R = 510 K

R = 1 M

R = 2 M

Suggested oscillator resistor values are shown below.

PT2262

PT2272

4.7 M

820 K*

3.3 M

680 K*

1.2 M

200 K**

Note:

* -- Operates when PT2272's Vcc=5V to 15V

** -- Operates when PT2272's Vcc=3V to 15V

This means that if PT2272 supply voltage is lower than 5V, you need to use a lower oscillator resistor

value for both PT2262 and PT2272.