LAPIS Semiconductor ML7345, Руководство по конструкции аппаратуры

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ML7345 Family LSIs Hardware Design Manual
8
4.1. Adjusting component values for VCO tank
Adjustment procedure of the VCO tank component
ｓ
is as below:
1. Execute the VCO calibration with the following condition.

Set the frequency to the center of usingfrequency range.

In the idle state with the room temperature.
2. Adjust the L1 and C1 values so that the calibration value obtained by [VCO_CAL] register (B0 0x6E)
becomes close to “64”(Decimal).

Reducing one or both L1 and C1 values if decreasing the VCO_CAL value.

Increasing one or both L1 and C1 values if increasing the VCO_CAL value.
[Note] In order to lock the PLL, the VCO_CAL value is required to be in the range from 1 to 126 (decimal) under
all conditions.
VCO calibration is required at customer manufactureing process (normal temperature contorol).In order
for the VCO_CAL value to be within the 64(dec)
±
20code by shipment test, use the deviation of L,C is
less than
±
2%
The frequency range that PLL can lock, VCO phase noise and the temperature feature depend on the L1, C1
values. It is recommended to evaluate these characteristics when L1 and C1 values is fixed.
Table 4.1.1 Representative component values for operating frequency
[Note] These component values appropriate for use on the LAPIS Semiconductor’s RF board. It is not guaranteed
to obtain same result on your specific board.
VCO tank
RF frequency
PLL(VCO)
Divider
setting
VCO
Oscillation
frequency(F)
L1 C1
ML7345
169MHz Divide by 6 1014MHz 4.3nH 2.0pF
426MHz Divide by 2 852MHz 4.7nH 3.9pF
868MHz
no divide
868MHz 4.7nH 3.9pF
920MHz
no divide
920MHz 4.3nH 3.3pF
ML7345C 470~510MHz
no divide
470~510MHz 33nH N.M.
ML7345D
868MHz no divide 868MHz 4.7nH 3.9pF
920MHz
no divide
920MHz 4.3nH 3.3pF