User Guide

PAMS
Technical Documentation
NSE–8/9
System Module
Page 2– 32
Issue 1 07/99
integrated into one ASIC, called the MAD2PR1 chip, which takes care of
all the signal processing and operation controlling tasks of the phone.
The Baseband architecture supports a power saving function called ”sleep
mode”. This sleep mode shuts off the VCTCXO, which is used as system
clock source for both RF and Baseband. During the sleep mode the
system runs from a 32 kHz crystal.
The phone is waken up by a timer running from this 32 kHz clock supply.
The sleeping time is determined by some network parameters. When the
sleep mode is entered both the MCU and the DSP are in standby mode
and the normal VCTCXO clock has been switched off.
The battery voltage in HD947,called Vb, is 1.8V to 3.6V depending on the
battery charge amount. The battery voltage is up converted to one of 4
voltage levels in the range from 3.1 V to 4.2 V, called Vdc_out, by means
of a DC/DC converter. The nominal level of the four Vdc_out voltages,
depends upon the required power level of the RF. The DC/DC converter is
always operating, provided that the input supply is greater than 1.8V and
with sufficient current capability.
The main part of the Baseband is running from 2.8V power rails, which is
supplied by a power controlling asic, CCONT.
The supply, Vcobba, for the analog audio parts, and the supply Vbb for the
main digital parts of the Baseband along with Vcore as supply possibility
for the core of MAD2PR1.
In the CCONT asic there are 7 individually controlled regulator outputs for
the RF–section. In addition there is one +5V power supply output (V5V),
also supplied to the RF.
The CCONT also contains a SIM interface, which supports both 3V and
5V SIM–cards. The SIM is supplied from a separate regulator, VSIM, in
CCONT.
A real time clock function is integrated into the CCONT, which utilizes the
same 32kHz clock supply as the sleep clock. The supply for the RTC is
taken directly from Vdc_out. Which means that when the battery is
removed the RTC may have to be set again at power up. However the
RTC will run for at least 24h after the phone has cut off due to low battery
power. Last but not least the CCONT supplies a 1.5V reference voltage,
Vref, for AD–converter usage in the Baseband and as reference voltage to
the RF.
The COBBA_GJP asic provides A/D and D/A conversion of the in–phase
and quadrature receive and transmit signal paths to the RF along with
AFC frequency control, AGC receiver gain control and TXC transmitter
power control. The remaining RF control signals are supplied by the
MAD2PR1, i.e. BAND_SEL for selection between 900 or 1800 MHz band,
FrACtrl for amplification control in the receiver front end, and tree signals