5

µPC2800A

2. EXAMPLE OF MEASURES TO PREVENT MALFUNCTIONING DUE TO NOISE

2.1 Radiation noise

•

Keep the wiring length between the PIN photodiode and pin 8 as short as possible.

•

Keep the signal lines of pins 2 and 6 as far away as possible from those of pins 7 and 8.

•

Commonly ground the anode of the PIN photodiode and the external capacitor connected to pin 7.

Separate the GND and power GND of pin 6 from these.

•

Cover the entire circuit in a shield case.

2.2 Power noise

•

Monitor the noise superimposed on pin 3 with an oscilloscope. If high-frequency noise is superimposed,

connect a ceramic capacitor of 0.1

µF or so between pin 3 and GND. If low-frequency noise is

superimposed, increase the capaciance of the capacitor between pin 3 and GND. If necessary, connect

a capacitor between pin 1 and GND.

2.3 External light disturbance noise

•

Use a PIN photodiode with an excellent spectral sensitivity.

•

Use a PIN photodiode with a lens and with a narrow directional angle.

2.4 Noise

•

gain. In this case, however, the distance is shortened and care must be exercised not to decrease the

voltage gain too much.

3. NOTICE FOR USE

The

µPC2800A is designed for the infrared remote control receivers of audio-visual equipment, air conditioner

and so on. Therefore the

µPC2800A may not be suitable for some applications that require accurate pulse widths

such as data communications. In case of using the

µPC2800A under the accurate pulse width condition, confirm

that the output pulses from pin 2 have enough accuracy in actual environmental changing (refer to the following

examples).

Example of environmental changing:

Operating ambient temperature, supply voltage, external disturbing light, external noise, input burst

length, input carrier frequency, strength of input light, direction of input light, distance from transmitter,

characteristics of parts (including the

µPC2800A) and so on.