User Guide

ISSUE 1 09/2004 COMPANY CONFIDENTIAL 37
Copyright © 2004 Nokia. All Rights Reserved.
RH-53/54
Nokia Customer Care
Receiver Troubleshooting
■ Front End Module (FEM) control signals
Depending on the vendor of the Front End Module (FEM), different timing of the control signals
are present. The SW suppoerts both FEMs. R629 tells the SW which FEM control should be
active. Renesas FEM control is used when R629 is 18K and RFMD FEM control is used when
R629 is 82K.
If the FEM is exchanged with an other type, the R629 must be changed, too.
Renesa FEM logic
Table 5: Renesa FEM logic
RFMD FEM logic
Table 6: RFMD FEM logic
Mode Vtx BS VC1 VC2
VTX_B_P VTX_B_P Vant1 Vant2
Low Band RX 0 0 0 0
Low Band TX 1 0 1 0
High Band RX 0 1 0 0
High Band TX 1 1 0 1
Vtx BS VC1 VC2
Mode VTX_B_P VTX_B_P Vant1 Vant2
Idle 0 0 0 0
Low Band RX 0 0 1 0
Low Band TX 1 0 1 0
High Band RX 0 1 1 0
High Band TX 1 1 1 0