Synthesizer; Transmitter (Tx) - Nokia RM-626 Service Manual

Älli contains the receiver chain from LNAs to digital base band interface. Digital RX baseband interface
contains four data and one clk signals. The data rate and clock frequency depend on the use case.
The main blocks in Älli are:
• LNAs: Balanced inputs for 850, 900, 1800, 1900, 2100 bands
• Passive mixer
• Analog baseband: Programmable for different modes
• ADC: Programmable Sigma Delta Modulator topology ADC
• RX Digital Front End (RXDFE): Contains for example digital filtering, DC offset compensation, wide/
narrowband power measurement blocks
There is integrated external LNA matching on the bands 900, 1800, 1900 and 2100. On 850 band, there is an
integrated matching.

Synthesizer

The synthesizer has separate highly integrated 4GHz VCOs for RX and TX. The integrator capacitors of the loop
filter are outside of the IC. The PLLs are fractional type of dividers.
The reference oscillator is an on-chip 38.4 MHz digitally controlled oscillator. The 38.4 MHz crystal is outside
of Älli. DCXO delivers the internal clock to Älli, differential clock signal to BB, and two single mode clock signals
to NCW modules. Älli delivers a clk signal to diversity RX. The oscillator is controlled via RFBus with AFC signal.
Temperature compensation of the oscillator is running by the SW in Älli. The temperature sensor itself is
outside of Älli.

Transmitter (TX)

The main features of Linko1 transmitter are:
• Common PA for GSM and WCDMA
• High and low band signal paths
• Low band: 824 - 915 MHz
• High band: 1710 - 1980 MHz
• Two operation modes in PA
• Saturation mode in GMSK usage
• Linear mode in Edge and WCDMA usage
• No TX filter between PA and Älli
• Common regulators for GSM and WCDMA
• Boost and SMPS regulators in Aura
• Feeding the supply voltage to PA
• Operation frequency varies depending on the used system
Frequency
WCDMA
GSM
• Digital interface to baseband
• WCDMA mode
• Digital IQ interface
• 3 data and 1 clk signals
Page 6 – 32
SMPS
3.0 MHz (typ)
9.5 MHz
COMPANY CONFIDENTIAL
Copyright © 2011 Nokia. All rights reserved.
Boost
4.5 MHz (typ)
7.5 MHz
RM-626
System Module
DCDC
1.3 MHz (typ)
2.7 MHz
Issue 1