AK1541_17 Datasheet, PDF (20/37 Pages) Asahi Kasei Microsystems – 20 to 600Mhz Delta-Sigma Fractional-N Frequency Synthesizer

[AK1541]
10. Register Functional Description
< Address 1: Num >
D19 D18
D[17:0]
00
NUM[17:0]
Note) Writing into address 0x01 is enabled when writing into address 0x02 is performed.
NUM[17:0] : Set the numerator in 2’s complementary representation.
< Address 2: Int >
D19
D[18:15]
0
CP1[3:0]
D[14:0]
INT[14:0]
Address
0001
Address
0010
CP1[3:0]: Sets the current value for the charge pump in normal operation (Charge Pump 1).
The minimum current value for Charge Pump 1 (CP1_min) is determined by the following formula:
CP1_min = 0.285 / Resistance connected to the [BIAS] pin
Charge Pump 1 current = CP1_min x (CP1 setting + 1)
CP1[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
22kΩ
13.0
25.9
38.9
51.8
64.8
77.7
90.7
103.6
116.6
129.5
142.5
155.5
168.4
181.4
194.3
207.3
Charge Pump 1 current [µA]
27kΩ
10.6
21.1
31.7
42.2
52.8
63.3
73.9
84.4
95.0
105.6
116.1
126.7
137.2
147.8
158.3
168.9
33kΩ
8.6
17.3
25.9
34.5
43.2
51.8
60.5
69.1
77.7
86.4
95.0
103.6
112.3
120.9
129.5
138.2
INT[14:0] : Sets the integer.
MS1043-E-05
20
2013/03