AK1541_17 Datasheet, PDF (24/37 Pages) Asahi Kasei Microsystems – 20 to 600Mhz Delta-Sigma Fractional-N Frequency Synthesizer

[AK1541]
< Address 4: Cp_fast >
D19 D18 D17 D16
D[15:13]
0 0 0 FASTEN CP2[2:0]
D[12:0]
FAST[12:0]
Addres
01s00
FASTEN: Enables or disables the Fast Lockup mode.
D16
Function
0 The switchover settings specified in CP2[2:0] and FAST[12:0] are disabled.
1 The switchover settings specified in CP2[2:0] and FAST[12:0] are enabled.
Remarks
CP2[2:0]: Sets the current value for the charge pump for the Fast Lockup mode
(Charge Pump 2).
The minimum Charge Pump 2 current (CP2_min) is determined by the following formula:
CP2_min = 5.7 / Resistance connected to the [BIAS] pin
Charge Pump 2 minimum current (CP2_min) = CP2_min x (CP2 setting + 4)
CP2[2:0]
000
001
010
011
100
101
110
111
Charge Pump 2 current [mA]
22kΩ
27kΩ
33kΩ
1.04
0.84
0.69
1.30
1.06
0.86
1.55
1.27
1.04
1.81
1.48
1.21
2.07
1.69
1.38
2.33
1.90
1.55
2.59
2.11
1.73
2.85
2.32
1.90
MS1043-E-05
24
2013/03