AK1544 Datasheet, PDF (21/37 Pages) Asahi Kasei Microsystems – 1300MHz Integer-N Frequency Synthesizer

[AK1544]
* Requirements for A[5:0] and B[12:0]
The data at A[5:0] and B[12:0] must meet the following requirements:
A[5:0]≥0, B[12:0]≥3, B[12:0]≥A[5:0]
See “1. Frequency Setup” on P.11 for details of the relationship between a frequency division
number and the data at A[5:0] and B[12:0].
< Address 2: CP >
D19 D18 D17 D16 D15 D14 D13 D12 D[11:10] D[9:6] D[5:4]
D[3:0]
00000000
0
CP2[3:0]
0
CP1[3:0]
CP1[3:0] : Charge pump current for normal operation
CP2[3:0] : Charge pump current for the Fast Lockup mode
Address
0010
In the AK1544, two types of charge pump current CP1 and CP2 could be set.
CP1 is the charge pump current setting for normal operation.
CP2 is the charge pump current setting for the Fast Lockup mode.
The following formula shows the relationship between the resistance value, the register setting and
the electric current value.
Charge pump minimum current (Icp_min) [A] = 8.55 / Resistance connected to the [BIAS] pin ohm]
When CP1 or CP2 is 0000 to 0111, charge pump current [A] = Icp_min [A] × (CP1 or CP2 + 1).
When CP1 or CP2 is 1000, charge pump current [A] = Icp_min [A] / 2.
CP1[3:0]
CP2[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
Charge pump currents [A]
22kΩ
27kΩ
33kΩ
390
320
260
780
630
520
1170
950
780
1550
1270
1040
1940
1580
1300
2330
1900
1550
2720
2220
1810
3110
2530
2070
195
160
130
MS1350-E-01
21
2013/03