If you are looking for a flexible RFID chip to develop multiple devices for IoT solutions your RFID chip should allow you to create a good BAP tag.

We talked about what the sensitivity is and how important it is for your next battery free solution.

However, we did not mention that you may want to use the same RFID chip to develop a BAP tag. These tags use the same communication protocol as battery free tags – EPC C1G2 commands – but use batteries for different reasons.

BAP tag for data logging

One of the limiting factors of battery free sensors is the inability to take measurements when there’s no RFID reader around. As there is no RF field to harvest energy from, the battery free RFID tag cannot perform any measurement.

In order to solve that, batteries can be used to power up the sensor and auxiliary electronics.

Your tags DOES NOT NEED BAP capabilities for this as you can design your solution with an external battery that does not get in contact with the RFID chip at all. It will only supply power to the external devices so that the sensor takes measurements and stores them into a memory.

BAP tag with improved sensitivity

Another limiting factor of battery free sensors is the read range. Due to the low power available, the read range is generally limited by the energy transfer.

If you are working with a RFID chip with BAP capabilities, the chip should noticeably increase its sensitivity. Having access to extra energy, the limiting factor in for the reading distance will be the communication, not the energy.

A BAP tag will have a read range according to its demodulation and modulation capabilities.

BAP tag read range

For this reason, it is always important that you double check with your RFID IC provider that the BAP feature stands for ‘improved sensitivity’.

You should get a value of sensitivity for passive mode and a different value – hopefully a lot higher – for BAP mode.

There’s also the possibility that some chips allow you to configure the sensitivity in BAP mode. This basically lets you decide if you want to communicate to longer read ranges at the expense of running out of battery faster. Make sure you request data of the current consumption in each of the configurations.

BAP tags being read after running out of batteries

If you are thinking about developing battery assisted passive tags you should take this seriously.

BAP tags can work for a certain amount of time but at some point the batteries will die. Will you need your solution to communicate with a RFID reader after that happens or not?

As an example, you have a BAP ID tag you designed for longer read range. It is not a data logger, just extending read range but… do you need it to be readable after its battery is finished, even if it is at a closer range?

As a different case, you have a BAP data logger designed for cold chain monitoring. It all goes well until it runs out of batteries but, if that happens, do you still want to be able to download the previously stored information?

If your reply to any of the questions above was YES, you will have to make sure that’s a possibility with your chip.

Take these things into account when selecting your RFID chip for IoT solutions, specially when you have BAP tags in mind.