The handset consists of the following major integrated circuits:
1) E-GOLD – PMB2851E
This IC is a combination of microprocessor, signal processor and real-time clock.
The microprocessor part of this component is responsible for controlling the keyboard, SIM-
Card, Flash and RAM. Furthermore it controls the power saving, power up/power down of the
RF module and sets the amplification of the PA.
The signal processor part of PMB 2851E is responsible for processing the Rx I/Q signals
(filtering, equalizing, speech and channel decoding).
Furthermore it does the speech and channel encoding and the GSMK modulation of the Tx
I/Q signals. The Voice CODEC part is used to realize advanced features regarding coding of
the speech signal. These are:
Enhanced Fullrate Encoding
Enhanced Fullrate Decoding
Voice Activity Detection
2) GAIM – PMB2906
The GAIM (GAIM = GSM Analog Interfacing Module) provides the interface between the
analogue and its digital representation signals (Base-band I/Q, Voice-band, PA-control,
Voltage & Temperature Measurement - Charging control).
3) 13Mhz Ref Oscillator Circuit -
This circuit provides the following main functions:
Generate 13Mhz clock signal for Logic Circuits – SIN13M.
Generate 13Mhz reference signal for the PLL circuits for the Tx & Rx of GSM RF signal.
Received the frequency steering control AFC_PNM from the HiGOLD IC for fine tuning
of the Tx & Rx frequency.
Temperature dependent resistor sited near the 13MHz oscillator measure the