TSOP1138SK1 VISHAY [Vishay Siliconix], TSOP1138SK1 Datasheet - Page 5

• Manufacturer Part Number: TSOP1138SK1
• Description: IR Receiver Modules for Remote Control Systems
• Manufacturer: VISHAY [Vishay Siliconix]

TSOP11..SK1
VISHAY
Vishay Semiconductors
Suitable Data Format
The circuit of the TSOP11..SK1 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:
IR Signal from fluorescent
lamp with low modulation
• Carrier frequency should be close to center fre-
quency of the bandpass (e.g. 38 kHz).
0
5
10
15
20
• Burst length should be 6 cycles/burst or longer.
Time ( ms )
16920
• After each burst which is between 6 cycles and 70
Figure 14. IR Signal from Fluorescent Lamp with low Modulation
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
TSOP11..SK1 it can still receive the data signal. How-
ever the sensitivity is reduced to that level that no
unexpected pulses will occur.
Some examples for such disturbance signals which
are suppressed by the TSOP11..SK1 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).
Document Number 82159
www.vishay.com
Rev. 2, 05-May-03
5