Nokia 6021 Service Manual
Issue 1 04/2005
COMPANY CONFIDENTIAL
33
Copyright © 2005 Nokia. All Rights Reserved.
RM-94
6(b) - RF Troubleshooting
Nokia Customer Care
Figure 3:Typical frequency tuning curve for the FDK VCO
Even if the PLL is not working properly (Vc outside the valid range), a frequency at the output
of the VCO can be detected between 3GHz and 4.4 GHz (if the VCO itself is ok and the supply
voltage VR7 = 2.78V is applied).
of the VCO can be detected between 3GHz and 4.4 GHz (if the VCO itself is ok and the supply
voltage VR7 = 2.78V is applied).
If the frequency or the tuning voltage have other values than given above, see the fault finding
chart for PLL syntesizer below.
chart for PLL syntesizer below.
Temperature: +25°C
3000
3500
4000
4500
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
VCTRL [V]
Frequency [MHz]
2.55V @ 24.4 .. 25.4°C
2.7V @ 24.4 .. 25.4°C
2.85V @ 24.4 .. 25.4°C
High limit
Low limit