TSOP4838UH1B Vishay, TSOP4838UH1B Datasheet - Page 5

• Manufacturer Part Number: TSOP4838UH1B
• Manufacturer: Vishay

Specifications of TSOP4838UH1B

• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Pin Count: 3
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Compliant

Suitable Data Format
The circuit of the TSOP48..UH1 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 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 time 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
TSOP48..UH1 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 TSOP48..UH1 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 13 or Fig-
ure 14 ).
Document Number 82128
Rev. 1.4, 01-Mar-05
Figure 14. IR Signal from Fluorescent Lamp with high Modulation
Figure 13. 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
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5
Time ( ms )
Time ( ms )
10
10
Vishay Semiconductors
TSOP48..UH1
15
15
20
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www.vishay.com
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