AMIS-53050 Datasheet, PDF (56/107 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53050 Frequency Agile Transceiver
Data Sheet
Table 32: Receiver Timing
Timing
Symbol
Min.
Typ.
Comments
Max. Units
T_PRE
MOD¹
MOD¹
D Bits
The TX preamble should be made long enough to allow the receiver to
acquire the signal
T_E
0
255
D Bits
The energy dwell timer should be set long enough to allow the receiver to
detect the energy²
T_ID
0
255
D Bits
The ID dwell timer should be set long enough to allow the receiver to detect
the chip ID or global ID²
T_LOP
Notes:
1.
2.
1
Default
255
D Bits
The length of packet will turn the receiver off after the number of data bits is
received
Indicates the need for a preamble and the type of preamble is determined by the data modulation selected.
The dwell timers need to be long enough to allow the receiver to stay active from the time it turns on due to energy and the time that the desired event occurs.
However, if the dwell times are set to their maximum value, in the case of false energy detection or signal corruption, excessive power dissipation results
The RX config register is used to set options for receive mode operation.
Wake on Energy: When enabled, the CDR circuit is held in reset until the energy threshold is met. This option can be used to
make the normal receiver function to perform similar to sniff. The energy dwell timer is used to determine how long the
receiver will stay on checking for energy (with FF in the energy dwell time register, the receiver will stay on until the threshold
is met).
Gate on Energy: This option can be used in FM receive mode only, and will gate the data interface while the energy on RSSI
is below the energy threshold.
LNA Mode: The LNA can be configured for the following performance:
1. Normal gain mode reduces the current requirement for the LNA, but will loose some gain or sensitivity.
2. High gain mode delivers the best sensitivity but increases the current requirement also.
3. Linear mode sets the LNA to have less sensitivity than the high gain mode and more sensitivity than the normal
gain mode while requiring less current than the high gain mode.
AM_FM_RX: Sets the mode of operation for receive
Force Multi-Channel: When this bit is set, the bits in Status/Flag2 register (which usually show which channel the radio is on)
can be overwritten to force the AMIS-53050 to operate on a particular channel.
Typically the sequence should be to:
1. Write register 0X0E bit 3 to force the AMIS-53050 into force multi-channel channel mode
2. Write register 0X02 bits [7:4] to select the channel frequency to use
3. Command the AMIS-53050 to transmit or to receive
AMI Semiconductor – Jan. 07, M-20639-002
56
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