AK1542A Datasheet, PDF (21/37 Pages) Asahi Kasei Microsystems – 20 to 600MHz Integer-N Frequency Synthesizer

[AK1542A]
* Requirements for A[5:0] and B[12:0]
The data at A[5:0] and B[12:0] must meet the following requirements:
B[12:0] ≥ 3, B[12:0] ≥ A[5:0]
See “1. Frequency Setup” on Page 11 for details of the relationship between a frequency division
number and the data at A[5:0] and B[12:0].
< Address2 : CP >
D19 D18 D17 D16 D15 D14 D13 D12 D[11:10] D[9:6] D[5:4]
00000000
0
CP2[3:0]
0
CP1[3:0] : Charge pump current for normal operation
CP2[3:0] : Charge pump current for Fast Lock Up mode
D[3:0]
CP1[3:0]
Address
0010
In AK1542A, 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 Fast Lock Up mode.
The following formula shows the relationship between the resistance value, the register setting and the
electric current value.
Setting 0~7;
Charge pump minimum current (Icp_min) [A] = 8.55 / Resistance connected to the [BIAS] pin (Ω)
Charge pump current [A] = Icp_min [A] × (CP1 or CP2 + 1)
Setting 8;
Charge pump current [A] = Icp_min [A] × 0.5
CP1[3:0]
CP2[3:0]
000
001
010
011
100
101
110
111
1XXX
Charge pump currents [µA]
22kΩ
27kΩ
33kΩ
388
776
1164
1552
1940
2328
2716
3104
194
316
632
948
1264
1580
1896
2212
2528
158
259
518
777
1036
1295
1554
1813
2072
129
MS1399-E-00
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