This circuit provides the following main functions:
•
Control of switch on of the Mobile phone by ON/OFF button, Ext Power (Charger) or real
time clock.
•
Watchdog monitor – switch off the mobile phone if no proper Watchdog signal send from
HiGOLD IC.
•
Voltage supply to the logic circuits – 2.90V, 2.65V & 1.92V, Simcard & real time clock in
HiGOLD IC.
•
Switch on the linear regulator to supply the 2.8V for the13Mhz Oscillator circuit.
•
RESET signal for the logic circuit.
•
Charge control signal for switching the charge FET.
•
Low battery detector.
•
Over voltage protection.
5)
Receiver Circuit – Bright II HD155124F
This circuit provides the following main functions:
•
Low Noise Amplifier (LNA) with a fixed amplification of +20dB to amplify the input RF
signal.
•
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
2dB).
•
Mixer to mix down the IF signal to the baseband, generating and inphase (I) and a
quadrature (Q) signal and feed the GAIM IC base-band signal, RX I/Q for the decoding
of the digital signal for the HiGOLD IC.
6)
Transmitter Circuit – Bright II HD155124F
The GAIM IC generate the MOD I/Q base-band signal under the control of the HiGOLD IC
and feed the IQ modulator of the Bright II IC. The Bright II IC provides the IF synthesizer,
the I/Q modulator, prescaler to regulate the dual-band TX-VCO and feed the modulated GSM
signal to the PA.
The telephone support only 1.8V and 3V SIM card
For user with 5V SIM card, he need to upgrade the SIM card
through his service provider/network operator
