User Guide

NSW-4
Disassembly & Troubleshooting
PAMS Technical Documentation
Page 46
Issue 1 Final
Draft 08/00
 Nokia Mobile Phones Ltd.
RF ASIC DATA
General Info
EROTUS (N700) provides three main RF functions:
1. RX/TX IF blocks
2. PLLs for VHF and 1 GHz UHF
3. TX Power control circuits
The receiver block consists of IF buffers, active mixers, 6–multiplier
(3*+2*), AGC amplifier and limiter.
The transmitter section includes a digital gain step amplifier, a linear gain
control amplifier, a divider, an I/Q Modulator and control part for the
Transmitter Power Control loop.
The PLL section is controlled via the serial bus and contains both 1GHz
UHF and VHF PLLs and prescalers.
EROTUS ASIC
Erotus is a uBGA–package, so RF probing for the most signals is impos-
sible at EROTUS pins. Signals can be checked at those components, to
which the signals are fed to.
RX Front ends N701 and N721
Pin no. Pin name Nominal
level
Description
1 LO IN –5dBm Mixer LO input
2 Vdd buf 2.8V LO–buffer Vdd
3 LO out 0dBm LO–buffer output
4 GND 0 Ground
5 Vdd LNA 2.8V LNA Vdd
6 GND 0 Ground
7 LNA in – LNA RF input port
8 GND 0 LNA ground
9 Gain Sel >2V LNA gain select
10 LNA out – LNA output port
11 GND 0 Ground
12 Mxr RF – Mixer RF input port
13 GND/ IF 0 Ground (–IF tuing in N721)
14 MXR IF – Mixer IF input port
15 GND 0 Ground
16 Vdd MXR 2.8V Mixer LO–buffer Vdd and LO–buffer tuning