AK1545 Datasheet, PDF (25/39 Pages) Asahi Kasei Microsystems – 3.5GHz Low Noise Integer-N Frequency Synthesizer

[AK1545]
< Address2 : Function >
D18
D17 D[16:14] D[13:10]
D9
D8
0
PD2
0
TIMER[3:0] FASTMODE
0
D7
FASTEN
D6
D5
D[4:2]
D1
D0
Address
CPHIZ CPPOLA LD[2:0]
PD1
CNTR_RST
02
PD2, PD1 : Power Down Select
[PDN]
<Address2>
{PD2} {PD1}
Function
“Low”
X
X Power Down
“High”
X
0 Normal Operation
“High”
0
1 Asynchronous Power Down
“High”
1
1 Synchronous Power Down
X : Don’t care
{PD2}=1 and {PD1}=1 : All circuits powers down at the timing when the Phase detector frequency
signal reverses.
{PD2}=0 and {PD1}=1 : All circuits goes into Power Down at the rise up of LE signal that latches 1 into
{PD1}.
TIMER[3:0] : Sets the Fast Lock Timer
This is enabled when { FASTMODE } =”1”, {FASTEN} = “1” and {CPGAIN}=”1”.
The charge pump current is set into high value (1mA) designate during switchover time which is set by
{TIMER[3:0]}.
The following formula shows the relationship between the switchover time and the counter value.
Switchover time = 1 / F_PFD x Counter Value
Counter Value = 3 + Timer[3:0] x 4
MS1471-E-00
25
2012/10