AT88RF1354 Datasheet, PDF (15/50 Pages) ATMEL Corporation – 13.56 MHz Type B RF Reader Specification

13.56 MHz Type B RF Reader
7.2.
Application
In a typical application the AT88RF1354 reader circuitry and the loop antenna are integrated on a single four layer
printed circuit board. The host microcontroller and power supply may reside on the same PCB, or on a separate PCB
depending on the application requirements.
The passive components required for the reader IC to function are placed in a small area immediately surrounding
the QFN package for optimum RF circuit performance. The PCB loop antenna is placed a minimum of 1 inch away
from all other metal, including the reader circuit ground and power planes, to minimize distortion of the magnetic field
which reduces RF communication performance. A typical loop antenna is designed for an inductance of 800 to 1600
nanohenries, DC resistance of 0.1 to 0.3 ohms, low parasitic capacitance, and includes a matching electric field
shield.
Whether the power supply and microcontroller are integrated in the same board or are on a different board, power
filtering is included at the edge of the reader circuit ground and power planes to isolate the reader from in-band
system noise and to protect the host microcontroller from reader generated noise. The reader ground and power
planes must be isolated from the balance of the system to prevent current loops from forming which will interfere with
RF tag performance.
Layout of both the reader circuitry and loop antenna are critical, and are beyond the scope of this document. See the
reference designs in the AT88RF1354 Application Notes for layout and circuit recommendations.
Figure 4. Typical AT88RF1354 Reader board layout
Power Supply
Microcontroller
Circuit
Reader
Circuit
Loop
Antenna
8547A−RFID−10/08
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