AMIS-53050 Datasheet, PDF (51/107 Pages) AMI SEMICONDUCTOR – Frequency Agile Transceiver

AMIS-53050 Frequency Agile Transceiver
Data Sheet
Table 25: System Clock Control
Register
Number (HEX) Name
0X0C
General options A
0X0D
General options B
0X10
Idle config
Function
Bits
11 POR starts in TX
10 POR starts in RX
2,1
01 POR starts in idle
00 POR starts in standby
0 Standby mode with system clock output
11 External XTAL reference divided by 2 (12MHz)
10 External XTAL reference divided by 4 (6MHz)
1,0
01 External XTAL reference divided by 8 (3MHz)
00 System clock off
11 System clock continues for 1024 clock cycles
10 System clock continues for 512 clock cycles
4,3
01 System clock continues for 256 clock cycles
00 System clock shuts down after idle command ASAP
Register descriptions:
Crystal Oscillator Trim- The value of the calibration for the 10kHz oscillator. (See Section 6.10.1.1)
6.4.4. Quick Start
The AMIS-53050 includes the ASTRIC family patented Quick Start oscillator. This circuit uses a “kicker” to force the crystal oscillator
close to the final desired frequency. This reduces the time required for the crystal oscillator to settle to the RF frequency. Information on
the Quick Start circuit can be obtained in the following documents: QuickStart.doc, and AMIS-53XXX_QuickStartAppNote.pdf.
Table 26: Kicker Calibration
Register
Number (HEX)
Name
0X28
RF PLL Options
Function
Bits
7 Kicker calibration status
Register descriptions:
Quick Start Trim- The value of the calibration for the kicker. (See Section 6.10.1.3)
6.4.5. Self Calibration
The AMIS-53050 has internal trim functions for the PLL, TX PLL, RX PLL, 10kHz oscillator, and kicker (Quick Start). A self calibration
is started by writing an instruction to the command register. This self calibration needs to be done at least once after the AMIS-53050
has been powered on and before the AMIS-53050 is placed into any mode such as transmit or receive. In this case, the application
should monitor the status registers and trim value registers to determine that the calibration was successful.
Note: The frequency of the AMIS-53050 can change a small amount (possibly as much as +/- 10MHz at 915MHz) without requiring a
new PLL calibration. This tolerance depends on the frequency and VCO coil, so would have to be empirically determined for an
application.
Note: An RF signal input to the receiver is required when performing the LNA calibration, therefore this calibration is not typically
performed. An application designed with the AMIS-53050 should consider the proper way to do an LNA calibration or even if an LNA
calibration is needed.
AMI Semiconductor – Jan. 07, M-20639-002
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