BOOSTXL-TLV8544PIR: Ways to reduce noise

Ying Rui Sebestian Tan

Part Number: BOOSTXL-TLV8544PIR
Other Parts Discussed in Thread: TLV8544

Hi,

My client is having an issue with BOOSTXL-TLV8544PIR. By using the GUI provided, the EVM works well when the laptop is running on batteries. However, when the laptop is connected to the laptop's AC adapter, the waveform become very noisy.

The customer views that the design based on TLV8544 is easily susceptible to noise. Is there any way to improve the performance and reduce the noise? Customer’s end application is LED lighting. They will have noisy power source and will need TLV8544PIR to work well under noisy environment.

Thanks and Regards,

Sebestian

Field Application Associate

over 4 years ago

0 Ron Michallick over 4 years ago

TI__Guru*** 140136 points

Ying,

The interference might be supply voltage, but I expect that the signal may be EMI through the air.

How close physically are the EVM board the the power brick for the laptop charger? Do the result change if the two are further apart?

0 Bala Ravi over 4 years ago in reply to Ron Michallick

TI__Expert 6625 points

Hi Ying,

Can you please provide the inputs and the outputs of TLV8544? Also please provide scope captures of the supply as well. We first need to find where the noise is being coupled in, to fix it. Please refer to the screenshot below that highlights the nodes that I'm referring to:

We currently do not have this EVM at our disposal. I will order them and in the meantime please provide us the requested data.

Best Regards,

Bala Ravi

0 Ron Michallick over 4 years ago in reply to Bala Ravi

TI__Guru*** 140136 points

Ting,

Have you solved your issue or gathered any of the requested data?

0 Ying Rui Sebestian Tan over 4 years ago in reply to Ron Michallick

TI__Prodigy 125 points

Hi Ronald,

Currently, I am trying to get a hold on the EVM and test out the scenarios. I will get back to you in a while.

Thanks.

Regards,

Sebestian

Field Applications Associate

0 Bala Ravi over 4 years ago in reply to Ying Rui Sebestian Tan

TI__Expert 6625 points

Hi Ying,

Please be aware that this thread will close if stayed inactive for 14 consecutive days. So please try to provide us some data before then.

Best Regards,

Bala Ravi

0 Ying Rui Sebestian Tan over 4 years ago in reply to Bala Ravi

TI__Prodigy 125 points

Hi Bala,

Thanks for the information. I will get back to you as soon as possible.

Regards,

Sebestian

0 Ying Rui Sebestian Tan over 4 years ago in reply to Ron Michallick

TI__Prodigy 125 points

Hi Ron,

I found out that the closeness between the power brick and the EVM will affects the noise in the circuit.

Power brick and EVM 10cm apart

Power brick and EVM 70 cm apart

Is there any other ways to reduce the noise?

Regards,

Sebestian

0 Bala Ravi over 4 years ago in reply to Ying Rui Sebestian Tan

TI__Expert 6625 points

Hi Ying,

We got the BOOSTXL-EVM couple days ago. We will try to replicate your setup and will let you know if we find other ways to minimize noise.

Best Regards,

Bala Ravi

0 Bala Ravi over 4 years ago in reply to Bala Ravi

TI__Expert 6625 points

Hi Ying,

I tried this experiment in lab. I got similar results for laptop connected to AC power vs using laptop's battery. I wasn't able to replicate your issue because I had a clean power source. Here are some ways to minimize noise:

1. You can try using shielded cables

2. You could place the EVM inside a Faraday's cage with some holes for PIR detection

3. If you can design your own board, you can include some RC filtering at the inputs

Moreover, this board was designed to demo PIR application using TLV8544. TLV8544 is a low power op-amp that can be battery powered for a PIR application. In real life application this will be powered off a battery where noise from power supply isn't an issue. I hope this help!

Best Regards,

Bala Ravi

Amplifiers

Amplifiers forum

BOOSTXL-TLV8544PIR: Ways to reduce noise