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Remote Control Encoder
PT2262
IR OPERATION
In the IR Type of Operation, the functions are similar to the above descriptions except for the output
waveform that has a carrier frequency of 38KHz. Details are as follows:
CODE BITS
The Code Bits are further modulated with a 38KHz carrier frequency and can be “0”, “1” or “f” bit. Their
waveforms are shown in the diagram below.
OSC
0
1
f
Sync
20λ
620λ
20λ
60λ
160λ
Note :
λ
= 2 clock lengths
CODE WORD
A Code Word is made up of code bits and the format is the same as that of the RF Code Word.
CODE FRAME
Likewise, a Code Frame is made up of Code Words and the format is the same as that of RF Type of
Operation.
OSCILLATOR
The Oscillator Frequency for the IR Type of Operation is twice the carrier frequency. Thus, the
oscillator frequency should be kept at 76 KHz. A 430K ~ 560KΩ oscillator resistor between OSC 1 and
OSC 2 pins is recommended. It should be noted that the carrier is a 50% duty cycle frequency.
PT2262 V3.8
-7-
September, 2008
PTC [ PRINCETON TECHNOLOGY CORP ]
