AMIS-53050 Datasheet, PDF (16/107 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53050 Frequency Agile Transceiver
Data Sheet
5.0 Hardware Description
5.1 Frequency
The RF frequency for both TX and RX modes is determined by the combination of internal VCO, PLL and trim capacitors, as well as an
external crystal oscillator. For the external crystal, it is recommended that a 24MHz parallel resonant mode crystal with 20ppm
tolerance be used, taking into account the internal capacitors.
Figure 4: External Crystal Circuit
The internal VCO requires an external, parallel LC configuration in order to properly set the frequency for RX or TX modes. Operation of
the AMIS-53050 is sensitive to the positioning of the LC components in the PCB layout. For this reason, the traces to the LC need to be
as symmetrical as is possible. The location of the LC components needs to be as close as possible to the transceiver pins as well. Any
layout changes will lead to a change in the VCO frequency, in turn requiring a change in the values of the inductor, capacitor and/or the
values in the register(s) controlling the RF frequency. The layout of the printed circuit board for the inductor and capacitor should route
AMI Semiconductor – Jan. 07, M-20639-002
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