AK1572 Datasheet, PDF (18/35 Pages) Asahi Kasei Microsystems – Down Converter Mixer with Fractional-N Frequency Synthesizer and VCO

[AK1572]
< Address0x04: function >
D[19：16]
CALTM [3:0]: Set the calibration precision of VCO
The register {CALTM [3:0]} determines the calibration precision and time for VCO. When
{CALTM [3:0]} is larger, the calibration precision increases, but the required time becomes
long as trade-off. The value calculated by the following formula is recommended to get
enough calibration precision. However, {CALTM [3:0]} should be set between from 1 to 11.
0 and over 11 is prohibited.
{CALTM[3:0]}≧ log₂(F_PFD/20000)
F_PFD : PFD frequency
The calibration time can be estimated as following calculation;
Calibration time = 1 /F_PFD × {(6 + 2^{CALTM[3:0]})×8 + 3}
D [14]
LDCNTSEL: Lock Detect Precision
Set the counter value for digital lock detect.
LDCNTSEL
0
1
Function
15 times Count
3 times Count
31 times Count
7 times Count
unlocked to locked
locked to unlocked
unlocked to locked
locked to unlocked
D [13]
LD: Lock detect function
Set the lock detect function.
0: Digital lock detect
1: Analog lock detect
D [12]
MTLD: Local signal mute
0: Don’t mute local signal in unlock state.
1: Mute local signal in unlock state.
※Please use {MTLD} =0 at the time of {LD}=1.
MS1551-E-00
18
2013/8