TSOP341..YA1
Document Number 82256
Rev. 1.1, 19-Apr-06
Vishay Semiconductors
www.vishay.com
5
Suitable Data Format
The circuit of the TSOP341..YA1 is designed in that
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 6 cycles/burst or longer.
• After each burst which is between 6 cycles and 70
cycles a gap time of at least 10 cycles is necessary.
• For each burst which is longer than 1.8 ms a corre-
sponding gap time is necessary at some time in the
data stream. This gap time should have at least same
length as the burst.
• Up to 2200 short bursts per second can be received
continuously.
Some examples for suitable data format are: NEC
Code, Toshiba Micom Format, Sharp Code, RC5
Code, RC6 Code, RCMM Code, R-2000 Code,
RECS-80 Code.
When a disturbance signal is applied to the
TSOP341..YA1 it can still receive the data signal.
However the sensitivity is reduced to that level that no
unexpected pulses will occur.
Some examples for such disturbance signals which
are suppressed by the TSOP341..YA1 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 (an example of the signal modulation is in the fig-
ure below).
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
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
VS - Supply Voltage (V)
17185
E - Sensitivity (mW/m )
2
e min
Figure 14. IR Signal from Fluorescent Lamp with low Modulation
0 5 10 15 20
Time (ms)
16920
IR Signal
IR Signal from fluorescent
lamp with low modulation