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Japan
Preamplifiers for Remote Control Reception
- Caution
- The PH302 is a discontinued product.
uPC2800A: Reception sensitivity
FAQ-ID : c2800-0001
- Q-1
-
How much variation is there in the reception sensitivity of the uPC2800A ?
The center frequency when using the PH302 photodetector from NEC Electronics is 70kHz.
An 800Ω resistor and 0.01uF capacitor are inserted in series at pin 7.
- A-1
-
The distance variation will be between about 0.65 times to 1.45 times the center value.
The following characteristics affect the sensitivity.
- (1) Variation of input resistance
-
The current of the current signal generated by the PIN photodiode
and converted into a voltage signal differs depending on the variation of the input resistance.
The sensitivity will vary from about -3dB to +2.5dB in accordance with the resistance variation. - (2) Voltage gain variation
-
There is a variation of about ±4dB in the voltage gain.
- (3) Variation of detector
-
The current of the current signal generated by the PIN photodiode
and converted into a voltage signal differs depending on the variation of the input resistance.
- Q-2
-
How do I adjust the reception sensitivity?
- A-2
-
The reception sensitivity can be adjusted by externally attaching a resistor to pin 7.
- Q-3
-
The description of pin 7 under 1. PIN FUNCTION in the data sheet includes the comment, "The gain of the amplifier can be adjusted by an external resistor (0 to 1kΩ)".
However, if a 10kΩ resistor is used, do any other problems occur except reduction of the reception distance?
- A-3
-
No, apart from a drop in the sensitivity, no other problems occur.
We have reference data showing a voltage gain of about 69dB when a 10kΩ resistor is used (C = 0.01uF), but this value is not guaranteed.
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