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PT2241 V1.5

- 8 -

March, 2006

Programmable Encoder IC

PT2241

In the Programming Technique used by PT2241, data are written/programmed into the chip two bits at

a time. The Clock contains 2 pulses and the burn-out time. Each pulse should be more than 1ms and

burn-out time should be greater than 80ms.

Please refer to the PT2241 Application Notes and the PT2241 Programming Manual.

SINGLE RESISTOR OSCILLATOR

The built-in oscillator circuit of PT2241 allows a precision oscillator to be constructed by connecting an

external resistor (Rosc) to the OSC Pin. For the PT2270 to decode correctly the received waveform,

the oscillator frequency of PT2270 must be 0.2 ~ 3.2 times that of the transmitting PT2241. The typical

oscillator frequency with various resistor values for both PT2241 and PT2270 are given below:

PT2241

PT2270

620KΩ

1.0KΩ

2.0MΩ

1.2MΩ

3.3MΩ

2.0MΩ

ENCODER (PT2241) OSCILLATION FREQUENCY

0

100

200

300

400

500

600

15 14 13 12 11 10

9

8

7

6

5

4

3 2.5 2 1.8

Vcc

(V)

430K

470K

1M

1.2M

1.5M

2M

2.2M

Rosc