New TSOP311../TSOP313..

Document Number 81763

Rev. 1.0, 09-Aug-07

Vishay Semiconductors

www.vishay.com

5

Suitable Data Format

The TSOP31#.. series is designed to suppress

spurious output pulses due to noise or disturbance

signals. Data and disturbance signals can be

distinguished by the devices according to carrier

frequency, burst length and envelope duty cycle. The

data signal should be close to the band-pass center

frequency (e.g. 38 kHz) and fulfill the conditions in the

table below.

When a data signal is applied to the TSOP31#.. in the

presence of a disturbance signal, the sensitivity of the

receiver is reduced to insure that no spurious pulses

are present at the output. Some examples of

disturbance signals which are suppressed are:

• DC light (e.g. from tungsten bulb or sunlight)

• Continuous signals at any frequency

• Modulated noise from fluorescent lamps with

electronic ballasts

For data formats with long bursts (more than 10 carrier cycles) please see the data sheet for TSOP312../TSOP314..

Figure 15. IR Signal from Fluorescent Lamp

with low Modulation

Figure 16. IR Signal from Fluorescent Lamp

with high Modulation

010

15

20

Time (ms)

16920

IR Signal from fluorescent

lamp with low modulation

5

010

15

20

Time (ms)

16921

IR Signal from fluorescent

lamp with high modulation

10

TSOP311..

TSOP313..

Minimum burst length

6 cycles/burst

6 cycles/burst

After each burst of length

A gap time is required of

6 to 70 cycles

10 cycles

6 to 35 cycles

10 cycles

For bursts greater than

A gap time in the data stream is needed of

70 cycles

> 1.2 x burst length

35 cycles

> 6 x burst length

Maximum continuous short bursts/second

2000

2000

Compatible to NEC code

yes

yes

Compatible to RC5/RC6 code

yes

yes

Compatible to Sony code

yes

no

Compatible to RCMM code

yes

yes

Compatible to r-step code

yes

yes

Compatible to XMP code

yes

yes

Suppression of interference from fluorescent lamps

Common disturbance signals are

supressed (Example: Signal pattern of

fig. 15)

Even critical disturbance signals are

suppressed (Examples: Signal pattern

of fig. 15 and fig. 16)