AMIS-53000 Datasheet, PDF (48/99 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53000 Frequency Agile Transceiver
Data Sheet
o Manchester encoding
o FFT or PLL demodulation (depends on data rate)
o Common data rates from 1.2kbps to 128kbps or user defined
The AMIS-53000 receiver is a low IF frequency single down conversion, sub-sampling, image rejection architecture with a common
AM/FM IF chain. Three demodulators are used for signal detection with additional post-detection and filtering capabilities for data
recovery.
A complex FFT demodulator is used for FSK signals with data rates > 20kbps.
A digital PLL demodulator is used for FSK signals with data rates less than 20kbps.
A logarithmic (RSSI) detector is used for OOK/ASK signals.
6.5.1. Receiver Circuit Brief Overview
Clock and Data Recovery: The AMIS-53000 can extract a synchronous clock signal from the received data. In this mode, the data in
the received signal is detected, filtered and then fed into the clock and data recovery block where additional digital filtering is performed.
The waveform is sampled using a data clock in the AMIS-53000 to synchronously recover the data. Signal sensitivity is improved and
the recovered data jitter is reduced by this method.
LO Frequency: A sub-sampling LO frequency architecture is implemented that down converts the incoming RF signal to the IF
frequency of about 500kHz. The LO frequency is produced from the internal VCO frequency. The frequency design of the LO signal
reduces the power consumption of the AMIS-53000 and simplifies the receiver, achieving reliable, quadrature LO signal generation.
IF Topology: The receiver implements a quadrature down-conversion architecture improving image rejection and creating the signals
required for the complex FFT FSK signal detection. The receiver uses this quadrature down-conversion and a combination of passive
and active poly-phase filtering to provide image suppression.
Sniff Signal Acquisition: As with earlier ASTRIC devices, the AMIS-53000 can reduce the receiver power requirements by
implementing the Sniff Mode for RF signal detection. Sniff Mode is a method using the Quick Start oscillator to quickly wake the
receiver, check for signal energy and return to sleep or start the receive function. The Quick Start can start the receiver crystal
oscillator in as little as 10 micro-seconds. Using this fast start time, the Sniff Mode can turn on the receiver, check for signal energy
and return to sleep in as little as 130 micro-seconds. More information about this Sniff Mode is in Section 6.7.2.
Table 32: Receive Command
Register
Number (HEX) Name
0X00
Command
Code
0X01
Function
Instruction to place the AMIS-53000 into receive
(remember that all parameters for receive must be set before issuing
this command)
Setup registers descriptions:
RX Config- Options for the receiver must be set.
RF Frequency- The RF frequency of the receiver must be configured. (See Section 6.4.1.1)
AMI Semiconductor – Aug. 05, Rev. 1.0
48
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