Tx Uhf Lo (N7000) Troubleshooting - Nokia 6255 Rf Description And Troubleshooting

Nokia Customer Care

Tx UHF LO (N7000) Troubleshooting

There are two fixed LOs, 3296.16~3395.88MHz for cell band and 3700~3819.90MHz for
PCS band. This is the only LO for up-conversion. Be sure to monitor the control voltage at
R7001. When the N7000 LO is locked, this control voltage should be between 1.2 and
1.8Vdc.
4
5
Table 18 shows the description for each component in Figure 51.
Test
Description
Point
1 Lock voltage
2 N7000: Measure voltage by probing
the top of the chip.
3 VIO
4 Vcc_Vco
5 VR6
Issue 2 05/2005
1 3
2
Figure 51: Tx UHF LO layout and test points
Table 18: Tx UHF Test Point Values
©2005 Nokia Corporation
6255/6255i/6256/6256i (RM-19)
RF Description and Troubleshooting
Value
DC between 1.2 and 1.8V
Cell channel 384: 3346.08MHz, -55 to -65dBm
PCS channel 600: 3760MHz, -54 to -65dBm
1.8V
2.3V
2.8V
Company Confidential
Cell PA
PCS PA
Page 61