User manual

TSOP312.., TSOP314..
www.vishay.com
Vishay Semiconductors
Rev. 1.1, 05-Feb-14
5
Document Number: 82492
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SUITABLE DATA FORMAT
This series is designed to suppress spurious output pulses
due to noise or disturbance signals. The devices can
distinguish data signals from noise due to differences in
frequency, burst length, and envelope duty cycle. The data
signal should be close to the device’s band-pass center
frequency (e.g. 38 kHz) and fulfill the conditions in the table
below.
When a data signal is applied to the product in the
presence of a disturbance, the sensitivity of the receiver is
automatically reduced by the AGC to insure that no spurious
pulses are present at the receiver’s output. Some examples
which are suppressed are:
DC light (e.g. from tungsten bulbs sunlight)
Continuous signals at any frequency
• Strongly or weakly modulated patterns from fluorescent
lamps with electronic ballasts (see figure 14 or figure 15).
Fig. 14 - IR Disturbance from Fluorescent Lamp
with Low Modulation
Fig. 15 - IR Disturbance from Fluorescent Lamp
with High Modulation
Notes
For data formats with short bursts please see the datasheet for TSOP311.., TSOP313..
Best choice of AGC for some popular IR-codes::
- TSOP31436: RC-5, RC-6, Panasonic
- TSOP31438: NEC, Sharp, r-map
- TSOP31456: r-step, Thomson RCA
For SIRCS 15 and 20 bit, Sony 12 bit IR-codes, please see the datasheet for TSOP4S40, TSOP2S40
0101520
Time (ms)
16920
IR Signal
5
0101520
Time (ms)
16921
IR Signal
5
TSOP312.. TSOP314..
Minimum burst length 10 cycles/burst 10 cycles/burst
After each burst of length
a minimum gap time is required of
10 to 70 cycles
10 cycles
10 to 35 cycles
10 cycles
For bursts greater than
a minimum gap time in the data stream is needed of
70 cycles
> 4 x burst length
35 cycles
> 10 x burst length
Maximum number of continuous short bursts/second 1800 1500
NEC code yes preferred
RC5/RC6 code yes preferred
Thomson 56 kHz code yes preferred
Sharp code yes preferred
Suppression of interference from fluorescent lamps
Most common disturbance
patterns are suppressed
Even extreme disturbance
patterns are suppressed