NSW-6
System Module SE2
PAMS Technical Documentation
Page 18
Issue 1 12/99
Nokia Mobile Phones Ltd.
internal and external devices. There are also all the AD– and DA– con-
verters for the RF interface.
DEMO block is used for FM–demodulation in analog mode.
A slow speed DA–converter provides automatic frequency control (AFC).
In addition, there is a DA–converters for transmitter power control (TXC).
COBBA also passes the RFC (19.44 MHz) to MAD as COBBACLK (9.72
MHz).
COBBA is connected to MAD via two serial buses:
– RXTXSIO, for interfacing the RF–DACs and DEMO; and also for audio
codec and general control. Signals used: COBBACLK (9.72 MHz, from
COBBA), COBBACSX, COBBASD (bi–directional data) and COBBA-
DAX (data ready flag for rx–samples).
– Codec SIO, for interfacing the audio ADCs / DACs (PCM–samples).
Signals: PCMDCLK (data clock 1.08 MHz / 1.215 MHz), PCMSCLK
(frame sync 8.0 kHz / 8.1 kHz), PCMTxdata and PCMRxdata.
PWRU
PWRU comprises CCONT circuit and CHAPS circuit.
CCONT Main Features
CCONT generates regulated supply voltages for baseband and RF.
There are seven 2.8 V linear regulators for RF, one 2.8 V regulator for
baseband, one special switched output (VR1_SW), one programmable 2
V output (V2V), one 3/5 V output, one 5 V output, and one 1.5 V +/– 1.5
% reference voltage for RF and COBBA.
Other functions include:
– power up/down procedures and reset logic
– charging control (PWM), charger detection
– watchdog
– sleep clock (32.768 kHz) and control
– 8–channel AD–converter.
CHAPS Main Features
CHAPS comprises the hardware for charging the battery and protecting
the phone from over–voltage in charger connector.
The main functions include
– transient, over–voltage and reverse charger voltage protection
– limited start–up charge current for a totally empty battery
– voltage limit when battery removed
– with SW protection against too high charging current
