AK1545 Datasheet, PDF (14/39 Pages) Asahi Kasei Microsystems – 3.5GHz Low Noise Integer-N Frequency Synthesizer

[AK1545]
Operation mode
Charge pump current
[SW] pin control
Normal
Fast Lock Up time
specified by the timer
Fast Lock Up
Low Value
High Value
Hi-Z
VSS
Normal
Low Value
Hi-Z
Fig. 6 Fast Lock Up Mode Timing Chart
Function
Fast Lock Mode
disable
Fast Lock Mode 1
Table 6 Fast Lock Mode Function
{FASTEN}={D7} {FASTMODE}={D9} {CPGAIN}
0
0
X
1
0
1
0
1
[SW]-pin state
{D9} state
Hi-Z
VSS
Fast Lock Mode 2
1
(*1) Controlled by the value in
1
{TIMER [3:0]}.
(*1) When the timer is counting, {CPGAIN} =”1” and [SW] pin is low state. After the timeout, its function reverts to
normal mode ({CPGAIN} =”0” and [SW] pin is Hi-Z state) instead of the fast lock up mode.
[SW]-pin Functions
SW pin is a General Purpose Output (GPO) pin which can be controlled by FASTEN register.
(1) {FASTEN} =”0”
The value of D9 register comes out from the SW pin.
AK1545
SW
■FASTMODE＝[D9]＝0 : SW＝“LOW” (CPVSS)
■FASTMODE＝[D9]＝1 : SW＝“HIGH” (CPVDD)
(2) {FASTEN} =”1”
Works as shown in the “Fast Lock UP Mode Timing Chart” above.
MS1471-E-00
14
2012/10