N7160 Receiver Overview - Nokia 6255 Rf Description And Troubleshooting

Nokia Customer Care
Table 12 includes the measure logic levels for the N7160.
If the logic levels are significantly off (+/- 0.2V), replace the N7160 and re-measure. If
the voltages are still out of specifications, refer to the Baseband Troubleshooting chapter.

N7160 Receiver Overview

Keep the following points in mind regarding the N7160 receiver:
• There is a separate LNA for 800MHz (Cell and AMPS) and 1900MHz (PCS).
• There is a separate RFA (inside N7160) for 800MHz (Cell and AMPS) and
1900MHz (PCS).
• After the RFA, there is a mixer, and then the signals are separated by CDMA (Cell
and PCS) and AMPS.
For example, if there is no IF frequency (128.1MHz) check both Cell and PCS. If
only one has 128.1MHz at L753, ensure that IF_SEL is working. If it is, then
replace the N750 due to a bad RFA.
If Cell and AMPS are working but PCS is not, look at the band select line and the
PCS LNA before replacing the N7160.
Issue 2 05/2005
Table 12: Rx Front-end (N7160) Logic Levels
Mode
IF_SEL
AMPS High Gain 2.8 V
AMPS Low Gain 2.8 V
Cell CDMA High Gain 0 V
Cell CDMA Low Gain 0 V
PCS CDMA High Gain 0 V
PCS CDMA Low Gain 0 V
©2005 Nokia Corporation
6255/6255i/6256/6256i (RM-19)
RF Description and Troubleshooting
Logic Input Voltages
BAND GAIN_CTL
0.1 V 2.8 V
0.1 V 0 V
0.1 V 2.8 V
0.1 V 0 V
2.7 V 2.8 V
2.7 V 0 V
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