The handset consists of the following major integrated circuits:
1) E-GOLD (PMB 2850)
This IC is a combination of microprocessor and signal processor.
The microprocessor part of this component is responsible for controlling the keyboard, SIM-
Card, Flash and RAM. Furthermore it controls the power up/power down of the RF module
and sets the amplification of the PA.
The signal processor part of PMB 2800 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
The coprocessor PMB 2805 is used to realize advanced features regarding coding of the
speech signal. These are:
Enhanced Fullrate Encoding
Enhanced Fullrate Decoding
Voice Activity Detection
3) GAIM (PMB 2906)
The GAIM (GAIM = GSM Analog Interfacing Module) provides the interface between the
analogue signals (I/Q, voiceband, PA-control, charging control signals) and its digital
4) Transceiver Circuit (Bright II HD155124F)
This circuit provides the following main functionalities:
Low Noise Amplifier (LNA) with a fixed amplification of +20dB to amplify the input RF
Mixer to mix down the RF signal to the Intermediate Frequency (IF)
Programmable IF amplifier with a dynamic range of 60dB ( -10dB ~+50dB in steps of
Mixer to mix down the IF signal to the baseband, generating and inphase (I) and a
quadrature (Q) signal.
Offset compensation for the I/Q signals.
This circuit provides the IF synthesizer, the I/Q modulator, prescalers to regulate the RF
synthesizer and a buffer stage to feed the PA.
The antenna switch is mechanical, located in the connector for the external antenna.
Power Supply Concept