PT2272A-L2 Princeton Technology Corp., PT2272A-L2 Datasheet - Page 8

• Manufacturer Part Number: PT2272A-L2
• Description: Remote Control Decoder
• Manufacturer: Princeton Technology Corp.

Remote Control Decoder
SINGLE RESISTOR OSCILLATOR
The built-in oscillator circuitry of PT2272 allows a precision oscillator to be constructed with only an
external resistor. For the PT2272 to decode correctly the waveform that was received, the oscillator
frequency of PT2272 must be 2.5 ~ 8 times that of the transmitting PT2262. It is a good practice to
center the PT2272 oscillator frequency in this window to gain best window margin at both sides. The
typical oscillator with various resistor values is shown below for both PT2262 and PT2272.
Suggested oscillator resistor values are shown below.
Note: * -- Operates when PT2272's VCC=5V to 15 V
This means that if the PT2272 supply voltage is lower than 5 V, you have to use a lower oscillator
resistor value for both PT2262 and PT2272.
PT2272 v3.5
100
10
1
KHz
** -- Operates when PT2272's VCC= 4V to 15V
3
Encoder OSC Frequency
6
V O L T A G E
9
12
PT 2262
4.7 MΩ
3.3 MΩ
1.2 MΩ
15
R = 510 K
R = 1 M
R = 2 M
R = 3.3 M
R = 4.7 M
- 8 -
1000
100
10
KHz
200 KΩ **
820 KΩ *
680 KΩ *
PT 2272
Decoder OSC Frequency
3
V O L T A G E
6
URL: http://www.princeton.com.tw
9
12
Fax: [phone]
Tel: [phone]
June, 2004
PT2272
15
R = 100 K
R = 240 K
R = 510 K
R = 1 M
R = 2 M