Panasonic KX-TG5771BXS, Service Manual, Page: 30 / 123

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KX-TG5771BXS/KX-TGA570BXS
4.9.3. 5.8 GHz Converter Circuit
This block converts frequency of TX signal and RX signal.
IC801 includes TX-MIXER, RX-MIXER, PLL and VCO modules internally.
The VCO module is tuned by PLL synthesizer module, and generates 3.4 GHz Local signal. Reference clock (13.824 MHz) from
DSP block is supplied to pin 7 of IC701.
2.4 GHz TX signal from 2.4 GHz Mod/Demod circuit is supplied to pin 17 of IC801, and internal TX-MIXER multiplies it by 3.4 GHz
Local signal from internal VCO module, and up-converts into 5.8 GHz TX signal. This 5.8 GHz TX signal is output from pin 2, and
goes into the 5.8 GHz PA circuit.
5.8 GHz RX signal from 5.8 GHz LNA circuit supplied to pin 5 of IC801, and internal RX-MIXER multiplies it by 3.4 GHz Local signal
from internal VCO module, and down-converts into 2.4 GHz RX signal. This 2.4 GHz RX signal is output from pin 15, and goes into
the 2.4 GHz Mod/Demod circuits.
Note:
The exposed GND_PLATE on the bottom of the IC801 supplies the circuit ground(s) for the entire chip. It is very important that
a good solder connection is made between this GND_PLATE and the ground plane of the PCB underlying the IC801.