TSOP322..SP1
Document Number 84666
Rev. 1.0, 31-Jan-05
Vishay Semiconductors
www.vishay.com
5
Suitable Data Format
The circuit of the TSOP322..SP1 is designed in such
a way that unexpected output pulses due to noise or
disturbance signals are avoided. A bandpass filter, an
integrator stage and an automatic gain control are
used to suppress such disturbances.
The distinguishing mark between data signal and dis-
turbance signal are carrier frequency, burst length
and duty cycle.
The data signal should fulfill the following conditions:
• Carrier frequency should be close to center fre-
quency of the bandpass (e.g. 38 kHz).
• Burst length should be 10 cycles/burst or longer.
• After each burst which is between 10 cycles and 70
cycles a gap time of at least 14 cycles is necessary.
• For each burst which is longer than 1.8 ms a corre-
sponding gap time is necessary at some point in the
data stream. This gap time should be at least 4 times
longer than the burst.
• Up to 800 short bursts per second can be received
continuously.
Some examples for suitable data format are: NEC
Code (repetitive pulse), NEC Code (repetitive data),
Toshiba Micom Format, Sharp Code, RC5 Code,
RC6 Code, R-2000 Code, Sony Code.
When a disturbance signal is applied to the
TSOP322..SP1 it can still receive the data signal.
However the sensitivity is reduced to such a level that
no unexpected pulses will occur.
Some examples for such disturbance signals which
are suppressed by the TSOP322..SP1 are:
• DC light (e.g. from tungsten bulb or sunlight)
• Continuous signal at 38 kHz or at any other fre-
quency
• Signals from fluorescent lamps with electronic bal-
last with high or low modulation
(see Figure 14 or Figure 15).
Figure 13. Sensitivity vs. Supply Voltage
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
2.02.53.03.54.04.55.05.56.0
V
S
– Supply Voltage ( V )
17185
E – Sensitivity ( mW/m )
2
e min
Figure 14. IR Signal from Fluorescent Lamp with low Modulation
Figure 15. IR Signal from Fluorescent Lamp with high Modulation
0 5 10 15 20
Time ( ms )
16920
IR Signal
IR Signal from fluorescent
lamp with low modulation
0 5 10 15 20
Time ( ms )
16921
IR Signal
IR Signal from fluorescent
lamp with high modulation