I have an RFID project going on, and it seems I need to maintain constant load on the LC tank, while powering the rest of the circuit from it as well.

So my idea is something similar to a TL431 shunt voltage regulator, but one that adjusts itself in such way that the rectified voltage from the LC tank is loaded by constant current, and thus cancels the fluctuation caused by the power going into the rest of the circuit.

So far I did´t even find a tl431 current sink without a boost transistor. Any help with that?

 

Hello,

How much current do you expect to be dumped?
The TL431 can handle between 1 and 100 mA.

Bertus

 

No more than 50mA.

 

Hello,

Have a look at figure 18 in the attached datasheet.

Bertus