Is this capacitor across the tsop solely for filtering

[Pro_Grammar]

Hey Guys. I'm using this tsop with an arduino as a proximity sensor.
The tsop pdf has the attached image with a capacitor across the suppply.
Is this capacitor solely for filtering. I omitted the RC network and it works fine.
I ask because I have a couple of them to do.
what does "mprove the robustness against electrical overstress" mean exactly.
thnx.
Rich.

 

[JimB]

Is this capacitor solely for filtering.

Yes.
It is there to remove noise and spikes from the supply line.

I omitted the RC network and it works fine.
I ask because I have a couple of them to do.

The circuit may work OK without them, but it would be better to install them.

what does "mprove the robustness against electrical overstress" mean exactly.

It is a fancy way of saying that the filter will remove high voltage spikes from the supply to the IR Receiver.

But, if there are voltage spikes on the supply, what about the micro controller?
Will that not be affected by the spikes?

JimB

 

[Pommie]

My guess would be that the Arduino's 5V supply is going to power the TSSP via it's 5V regulator or USB power so it should be fairly clean.

What are you going to use to produce the 38kHz IR emitter? Note, it also needs to be pulsed or the TSSP's Automatic Gain Control stops it seeing it. I switched it on/off every 0.5mS and that seemed to work fine. I used an Arduino Nano (ATMEGA328p) to produce 38kHz pulses using an interrupt and gated it on/off by making the pin input.

Mike.

 

[Nigel Goodwin]

You are correct, the resistor and capacitor are just for power supply filtering - but they MUST be included. If you leave them out it 'may' work most of the time, but it's likely to be both unreliable, and also provide false outputs.

The high value of the capacitor is a bit of a 'give away', as it's quite substantial (for what the circuit is).

I would suggest it's there not to remove 'spikes', but to remove 'dips' - and I would very strongly advise fitting them.

As someone who's repaired thousands of TV's, they ALL include those components - and TV production is notorious for saving even a single resistor.

 

[Diver300]

The application circuit is for the sensor, so any microcontroller could be used, and other than the voltage the power supply isn't specified either. Some power supplies will be noisy, and most microcontrollers take current spike of some sort, resulting in noise on their supply rails. The sensor manufacturer will add the filter components to increase the chances of the sensor working.

However it's not at all clear what increase that gives. It could be that there is no improvement if the supply is well regulated and the microcontroller has generous decoupling capacitors, or it could be that in many real-world situations the sensor fail often without the filter.

Many of the IR receivers will be fitted on devices like TVs that can connect to other devices, and it's impossible to predict exactly what the noise will be like when in use, so the manufacturers will play safe. If you want to run your one Arduino-based device without a filter, you're risking very little, as you can easily go back and add a filter if you need it.

 

[Pro_Grammar]

Thanks guys, I appreciate all the replies . I'll go ahead and add them.