DBTEL DB-6568, Руководство по обслуживанию

Страница: 48 / 73

DBTEL Incorporated
DB-6568 Service Manual Level 1 ~ 3
2003.11.13
DBTEL Copyright Reserved
Page 48 of 66
1. There are six sets of working voltage needed by chipsets, the voltage range is 2.4 ~ 3.6 V.
The 2.7V RFVCC is supplied by U501 VCC_RX_TX. The 2.7V of IFVCC1 and IFCPVCC
are supplied by VCC_IF that is converted from U501 VCC_RX_TX .The 2.7V IFVCC2 is
supplied by PIN_12__IFVCC2 that is converted from U501 VCC_SYN .The 2.7V
RFLOVCC is supplied by U501 VCC_SYN . The 2.7V SYNVCC is supplied by
PIN_23__SYNVCC that is converted from U501 VCC_SYN
。
2. There are 2 sets of Charge Pump signals supplied by chipset
，
TXVCP and RFVCP
respectively and supplied by U501 VCC_CP 4.0 V . The -0.4 ~ 3.6 (VCC-0.4) requested
voltage is generated by way of chip voltage divider.
3. The are 3 sets logic input status control signals, RXON
、
TXON and SYNON respectively; It
is high voltage level state above 0.9 V ,and low voltage level 0.3 V
The following signals are directly controlled by U301
。