AMIS-53050 Datasheet, PDF (46/107 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53050 Frequency Agile Transceiver
Data Sheet
Figure 33: EE Flow Diagram
6.4 Frequency
The AMIS-53050 uses an internal PLL/VCO to generate the RF frequency for both transmit and receive modes of operation. Only one
set of registers needs to be programmed to generate the TX frequency and to generate the LO frequency to produce the mixing
frequency for converting the received signal to the low IF (about 500kHz). The self-calibration process will in turn trim internal
capacitance to tune the TX and RX frequencies. The self-calibration process is to be executed at least once following start-up or after a
significant change in the RF frequency.
The on-chip processor will calculate four (300kHz) channels above and four (300kHz) channels below the center frequency entered into
registers 0X05, 0X06, 0X07 and 0X08, respectively. This occurs once a ROM2REGS instruction is executed. Caution is advised when
using any of the multi-channel features of the device, as the operating frequency could be altered.
6.4.1. Frequency Control
AMIS has developed an executable program (AMIS-53KFractNCalc.exe), available from AMIS, which generates the register values for
the frequency divider and 24-bit fractional word to produce a desired frequency. First, the AMIS-53050 must have the correct LC for the
AMI Semiconductor – Jan. 07, M-20639-002
46
www.amis.com