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AN912
Designing LF Talkback for a Magnetic Base Station
Author: Ruan Lourens Microchip Technology Inc.
MAIN BUILDING BLOCKS
Figure 1 shows the main building blocks that make up the LF Talkback system described in this document. The base station generates a strong magnetic field by setting up resonance in a serial resonant tank. The circulating energy in the resonant tank typically generates 300V peak-to-peak voltage across the transmitting antenna coil at 125 kHz. The transponder, whether active or passive, is magnetically coupled to the base station’s transmitting coil and the transponder’s magnetic loading has a small effect on the quality factor (Q) of the transmitter resonant tank.
AN912 Datasheet
