AMIS-53050 Datasheet, PDF (7/107 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53050 Frequency Agile Transceiver
Data Sheet
1.4.2.5. Manchester Data Encoding
The AMIS-53050 can encode the data as NRZ or Manchester. Manchester encoding can improve the communication link as the
encoding removes long time periods with the same level of multiple bits, without a data edge transition. Manchester encoding will
require that the data rate be half of the NRZ data rate.
1.4.2.6. Oscillators
The AMIS-53050 requires a single external crystal working with the internal VCO and PLL to generate frequencies from 300MHz to
960MHz. The AMIS-53050 has internal capacitors, which eliminate the need for external load capacitors when using a typical 24MHz
external crystal. The VCO requires an external inductor and capacitor (in conjunction with the internal capacitance) and user
programming of the device in order to produce the desired transmit or receive RF frequency. Due to parasitics associated with an
external capacitor, it is recommended that only a coil be used with the VCO unless the circuit cannot achieve the desired frequency
without a capacitor. A patented Quick Start circuit is used to force the crystal oscillator to the desired frequency in microseconds rather
than in milliseconds.
A low power internal 10kHz oscillator provides the timing for sniff, burst and housekeeping modes of operation. In this case, based on
integrated self-calibration circuitry, a frequency tolerance of +/- 2% can be achieved.
Crystal frequencies other than 24MHz may be used; however, this option is not recommended because:
• The Quick Start feature will not function
• The algorithm for determining the frequency register values will change
• The algorithm for determining the data rate register values will change
• The algorithm for determining the FSK modulation deviation register values will change
• The RF frequency operational range of the device will change
1.4.2.7. Interface Serial Bus
The AMIS-53050 has separate interfaces for data and control. The transfer of TX/RX data between the transceiver and an external host
controller is performed using a 3-wire serial interface or a 4-wire SPI compatible serial interface, respectively. Control information is
either written to or read from the appropriate register using either a 3-wire serial interface (only available with the AMIS-53050-002
version) or a 2-wire I²C compatible serial interface.
Once the data pertaining to the configuration of various modes of operation, such as transmit, receive, sniff, etc., is written to the
configuration register, placing the device into one of these specific modes is accomplished via a single write command.
TX/RX Data Interface
The transmit or receive data interface can be programmed to be either a proprietary 3-wire serial interface or a 4-wire SPI compatible
serial interface, respectively. The data interface can be set up for data transfer to a buffer or alternatively, for streaming data. In the
buffered data mode, the device can be configured as a master or a slave. However, it must be configured as a master in order to
process streaming data.
Control Interface
When the transceiver is first powered on, an external host controller can be used to configure the type of interface (3-wire or I²C) by
simply writing the desired protocol to the AMIS-53050. As long as power is not removed from the device, this configuration is
maintained. The AMIS-53050 is always a slave device for the control interface. The AMIS-53050-002 version does not bond the SSN
signal to an external pin of the AMIS-53050 pin. This version must use the I²C interface bus and the SSN line defaults to the correct
level to enable the I²C interface bus with the first write operation.
AMI Semiconductor – Jan. 07, M-20639-002
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