DC12V which is the output of AC adapter is supplied to the main set. The DC/DC converter (IC808)
converts DC12V to around 3.3V, and also generates the DC power supply needed for each block. The
voltage is divided into a 3.3V system, a 2.5V system and a 1.5V system.
The 3.3V system is supplied to each part as VDD33 (Control block), VDD332 (WAN block, LAN block)
and VRF (RF block).
The 2.5V system's voltage is transformed in the regulator IC (IC801) and is supplied to the WAN block
and LAN block as VSW25.
The 1.5V system's voltage is transformed in the regulator IC (IC802, IC803) and is supplied to each block
as VDD15 (Control block), VSWIS (LAN block).
11.2. RF BLOCK
11.2.1. Antenna
A
/2 dipole antenna is used.
MAC/BBIC (IC501) controls the antenna switch (IC506). It switches the external antenna so as to
transmit or receive.
11.2.2. Reception Block
The receiving signal from the antenna transits the antenna switch (IC506). The signal is then inputted to
RFIC (IC502) after being amplified by LNA (Low Noise Amp). The RFIC (IC502) incorporates the LNA
18
