AMIS-52100 Datasheet, PDF (14/26 Pages) AMI SEMICONDUCTOR – Transceiver with Clock and Data Recovery

AMIS-52100 Low-Power Transceiver with Clock and Data Recovery
Table 22: Transmitter Control Registers
TX/RX Definition Control Registers
Register (HEX) Name
0x02
TX power
0x04
TX XTAL trim
0x0c
TX enable
0x0f
Data filter
0x1e
TX/RX invert
Bits
All
All
4
4,5,6
5
States
0
1
000
001
010
011
100
101
110
111
0
1
Comments
Transmitter is off
Transmitter is on
1.1kHz
2.3kHz
5.2kHz
10.4kHz
1.18kHz
2.57kHz
7.0kHz
20.45kHz
Normal levels
Inverted
Table 23: Output Impedance Characteristics
Specification Settings
Conditions
Output
Resistance
Impedance
Capacitance
Output Power RFPWR 0x00
RFPWR 0xff
Harmonics
Ext circuit
Frequency
Target
Range
Quick Start
Full range
Modulation
On/Off Ratio
TX output
Min.
11
402
350
300
Typ.
22
3
-26
12
-35
ASK/OOK
70
Max.
13
405
448
768
Units
Ω
pFarads
dBm
dBm
dBm
MHz
MHz
MHz
dBm
Data Sheet
Figure 8: Transmit Waveforms
9.3 Sniff Mode
Very low power applications will want to program the AMIS-52100 to use the Sniff Mode. This mode turns the receiver and crystal
oscillator off for a programmed time. At the end of this time the receiver wakes and “sniffs” for incoming RF energy. If energy is
detected, the receiver wakes the full receive function and starts data recovery from the RF carrier. If energy is not detected, the receiver
returns to the low power or “sleep” state. The operation of the Sniff Mode is very programmable. The time that the receiver is asleep
can be programmed from microsecond to seconds. Once the receiver wakes to detect RF energy, there is a programmable delay
before the receiver checks for energy. There is another delay that accounts for circuit delays. Finally, there is a programmable delay
after energy is detected and before the receiver samples the recovered energy to determine the logical state of the recovered data.
Table 24 lists these registers. Refer to the AMIS application note “Sniff Mode” for more information.
Figure 9 and Figure 10 show waveforms that show the timing of the Sniff Mode.
AMI Semiconductor – Rev 4.0, Mar. 06 – M-20535-004
14
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