DBTEL DB-6568, Руководство по обслуживанию

Страница: 44 / 73

DBTEL Incorporated
DB-6568 Service Manual Level 1 ~ 3
2003.11.13
DBTEL Copyright Reserved
Page 44 of 66
4.4 U10 MOS FET Power Amplifier Module
1. PIN 3 & PIN 6 : make battery voltage stabilize and filter
，
supply 3~4.5V working voltage
。
2. Make U301 out put signal controls U10 PIN 7
，
When low voltage (0~0.1 V)
，
select PIN 1
GSM input signal (880~915 MHz /0 dBm)
，
When high voltage (2~2.8 V)
，
select PIN 8 DCS
input signal (1710~1785 MHz /0 dBm)
。
3. .By U30 output signal(0.2~2.2 V) supply U104 PIN 2
，
supply to PIN 4 as GSM coefficient
of amplify signal or as PIN 5 DCS coefficient of amplify signal
。
4.5 U40 GSM TX COUPLER