LG U8550 Service Manual page 80

Hide thumbs Also See for U8550:
Table of Contents

Advertisement

3. Technical Brief
D. VCO Block
The VCOs are fully integrated balanced LC oscillators with on-chip resonators.
The receive VCOs run on double frequency.
Different frequency ranges can be selected in the VCOs for GSM, DCS and PCS band operation.
The VCOs are supplied from a separated external voltage regulator to avoid frequency pushing and up
conversion of low frequency noise. A separate ground pin is also used as varactor ground reference to
prevent DC voltage drop changes from affecting the VCO frequency.
Figure 3-7-3 shows a block diagram of the VCO block.
Figure 3-7-3. Block diagram of the VCO part
- 81 -

Advertisement

Table of Contents
loading

Table of Contents