Bb Pll; Fig 46 Bb Pll - Nokia RH-13 Series Troubleshooting Manual

RH-13
Troubleshooting

BB PLL

The BB PLL generates RF clock to base band. It has two fixed frequencies 77.76 MHz in
TDMA mode and 78 MHz in GSM mode. Next picture shows BB PLL working.
19.2 MHz
VCTCXO
Divider
65 or 80
* Data
RF-IC
*Data are related to vctcxo frequency and mode selections.
Page 66
Figure 46: BB PLL.
Freq/Phase
comparator
Divider
324 or 325
Divider 4 or 6
RFCLK to BB
GSM 13 MHz
TDMA 19.44 MHz
ãNokia Corporation
CCS Technical Documentation
Charge Pump
Active
part
BB VCO
Loop Filter
Varactor
Resonator
Issue 1 11/02