TSOP34438SB1 Vishay, TSOP34438SB1 Datasheet - Page 5

• Manufacturer Part Number: TSOP34438SB1
• Manufacturer: Vishay

Specifications of TSOP34438SB1

• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 5.5V
• Mounting: Through Hole
• Pin Count: 3
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Compliant

Suitable Data Format
The circuit of the TSOP344..SB1 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 10 cycles/burst or longer.
• After each burst which is between 10 cycles and 35
cycles a gap time of at least 14 cycles is necessary.
• For each burst which is longer than 0.9 ms a corre-
sponding gap time is necessary at some time in the
data stream. This gap time should be at least 7 times
longer than the burst.
• Up to 400 short bursts per second can be received
continuously.
Some examples for suitable data format are: NEC
Code, Toshiba Micom Format, Sharp Code, RC5
Code, R-2000 Code.
When a disturbance signal is applied to the
TSOP344..SB1 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 TSOP344..SB1 are:
• DC light (e.g. from tungsten bulb or sunlight)
• Continuous signal at 38 kHz or at any other fre-
quency
Document Number 82275
Rev. 1.1, 28-Feb-05
96 12223p2
1.0
0.9
0.8
0.7
0.6
d
rel
0.4
– Relative Transmission Distance
0.2
Figure 13. Directivity
0
0
0.2
10
0.4
20
0.6
30
40
50
60
70
80
• Signals from fluorescent lamps with electronic bal-
last with high or low modulation
(see Figure 14 or Figure 15).
Figure 15. IR Signal from Fluorescent Lamp with high Modulation
Figure 14. IR Signal from Fluorescent Lamp with low Modulation
16920
16921
0
0
IR Signal from fluorescent
lamp with high modulation
IR Signal from fluorescent
lamp with low modulation
5
5
Time ( ms )
Time ( ms )
TSOP344..SB1
10
10
Vishay Semiconductors
15
15
20
20
www.vishay.com
5