AK1599V Datasheet, PDF (17/41 Pages) Asahi Kasei Microsystems – RF Transmitter for Satellite Communication

[AK1599V]
9.4. Frequency Settings
<Synthesizer settings>
The following formula is used to calculate the frequency setting for the AK1599V.
Setting Frequency = Ref Frequency * (INT + FRAC / MOD)
Ref Frequency : Phase detector frequency
INT
: Setting value of Integral divider (Refer to Address0x01: INT[11:0] bits)
FRAC
: Setting value of numerator (Refer to Address0x02: FRAC[11:0] bits)
MOD
: Setting value of denominator (Refer to Address0x03: MOD[11:0] bits)
Set INT[11:0] bits within a range from 35 to 4091.
Set FRAC[11:0] bits in accordance with following range : 0 ≤ FRAC ≤ (MOD-1).
Set MOD[11:0] bits within a range from 2 to 4095.
○ Calculation example
In order to achieve setting frequency = 3602MHz with Ref Frequency = 40MHz, set following values.
RFOUT Carrier frequency is the half of synthesizer setting frequency.
INT =
90
FRAC =
1
MOD =
20
Synthesizer setting Frequency = 40MHz * (90 + 1 / 20) = 3602MHz
RFOUT carrier frequency = 3602MHz / 2 = 1801MHz
Frequency Settings are done by setting Address0x01, 0x02 and 0x03. The settings of Address0x02 and
0x03 are reflected simultaneously with setting Address0x01. Synthesizer block should be powered on
before Address0x01 is set. Frequency settings, VCO calibration and Fast Lock Counter start its
operation simultaneously with setting Address0x01. In order to set frequency correctly, be sure to set
Address0x01 after setting PDN pin = ”H” and MODE[1:0] bits in Address 0x04 = “00” or “01”.
015006835-E-00
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2015/5