DBTEL Incorporated
DB-6568 Service Manual Level 1 ~ 3
2003.11.13
DBTEL Copyright Reserved
Page 46 of 66
impedence)
，
details to see Data Sheet
，
0.2 ~ 2.3 V in general
。
4.8 U170 TX VCO
1. PIN 11 consumes 2.7
±
0.2 V
，
supplied by 2.7 VCC_TX_BURST of U501
。
2. PIN 4 is controlled by EGSM signal of U301
，
When high voltage ( 2.0 ~ 2.9 V )
，
is GSM
MODE, output is by way of PIN 1 , PIN 2 is low voltage ( 0 ~ 0.3 V ) at this time
；
PIN 2 is
controlled by U301 DCS signal
，
When high voltage ( 2.0 ~ 2.9 V )
，
is DCS MODE ,
由
output is by way of PIN 5
，
PIN 4 is low voltage at this time ( 0 ~ 0.3 V )
。
3.When it is GSM MODE
，
PIN 8 supplies 0.8 ~ 3.0 V by U110
，
PIN 1 will output 880 ~ 915
MHz / -2 ~ 6.5 dBm signal
；
When it is in DCS MODE
，
PIN 8 is supplied 0.8 ~ 3.0 V by
U110
，
PIN 5 will output 1710 ~ 1785 MHz / -2 ~ 6.5 dBm signal
。
