Is it possible to make M24LR an active tag?

[Lchan.1]

After studying the datasheet of M24LR, I am not sure if I implement two 3v button batteries, the M24LR could send back some massage (like UID) to the reader with a stronger signal than other passive tags.

Here are my questions:

1: Will the signal strength be better after I use an external power source to VCC?

2: Can I achieve a protocol that the M24LR sends back the massage instantly after receiving a reading signal from the reader?

[JL. Lebon · Accepted solution]

Hello,

Connecting a power supply to the M24LR will not change the strength of it answer. The answer of the tag is a passive load modulation, meaning that the tag is modulating the 13.56MHz signal from the reader by changing its impedance. So, having an external power supply will not change anything on the answer signal strength. The external power supply of a M24LR purpose is to power the tag when using the I2C interface and has almost no impact on the RF interface performance.

For your second question, what do you mean exactly ?

If you want to change the protocol so that the tag instantly send a message when the RF field is present, it is not possible, as it is against the ISO15693 protocol.

If you want to answer immediately after receiving a read request, this is how it already works.

Best regards.

[Lchan.1]

thank you for your answer, it really solves all my questions.

What I want to build is an active tag(13.56Mhz) that will transmit enough RF signal strength for about 30cm. Therefore I am seeking a capable ic to fit in my design. It seems ML24LR may not suitable for my usage. Do you know any ic could achieve my requirement?

Or not implementing active tag. Is it feasible to combine ST25R3917 and ML24LR as reader and tag for 30cm?