Fmtx 2.1 Component Layout; Specific Digital And Power Supply Test Points; Fmtx2.1 Specific Rf Test Points - Nokia N900 Service Manual

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FMTx 2.1 component layout

Figure 20 FMTx 2.1 Component References and Location
The main component of the FMTx 2.1 solution is the Si4713 low power transmitter device (N6180).

Specific digital and power supply test points

Using access to signals figure as a reference it can be seen that supplies to the Si4713 device VIO 2/2 C6180
and VDD 1/2 C6180 can be accessed easily. The FMTx 2.1 solution utilises a QFN package. This type of package
lends itself well to analysis of signals on the various pins of the device.
VIO & VDD
VIO should be in the range 1.5 to 3.6 Volts.
VDD should be in the range 2.7 to 5.5 Volts.
_RST
Also, the _RST signal to the device can be monitored through test pin J6185. This is an active low signal and
should only be asserted during power up.

FMTx2.1 specific RF test points

TXO
FMTX output power can be measured from capacitor C6183 and probe access can be obtained easily. Using
a high impedance probe and a spectrum analyser it would be possible to examine the TXO output power and
check that the transmitter is outputting a signal.
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