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17

V_PA

V_RF

(*

1)

Ant

enna Ty

pe (

 di

ffer

ence bet

ween base uni

t and handset

 i

n

 Radi

o par

ts

)

ANT1: patterned antenna

K

X-TPA50 BLOCK DIAGRAM (Handset_RF Part)

ANT2: wired dipole antenna 

PLL

13.

824 MHz

ANT1 (

*1)

ANT2 (

*1)

Cont

ro

l

Logi

c

Mi

x

e

r

A/D

Dem

odul

at

or

D781

D771

BCLK

SYN_OUT

SYN_EN

SYN_CLK

SYN_DATA

SLOT_CTROL

RADIO_EN

TXDATA

RXDATA

RF_RSTN

delta-sigma Modulator

Divider

  1.5

18

The circuit mainly consists of DSP and RF part as shown in the block diagram.

• Battery Low, Power down detect circuit
• Ringer Generation
• Interface circuit

RF part, Speaker, Mic, LED, Key scan, LCD, Headset

(*1) The initializing time of the DSP chip is 20 ms under normal conditions.

Mainly voice signal is modulated to RF, or it goes the other way.

All setting data is stored.
ex: ID code, user setting (Phonebook, program data)

19

Voltage is supplied separately to each block.

20

The voice signal from the microphone is input to DSP (90, 91). CN431 is the headset jack. When the headphone is connected,
the R436/R437 detects it. The input from the microphone of the handset (MIM, MIP) is cut and the microphone signal from the
headset is input to DSP (95). Also the power for the microphone is supplied from DSP (92) and the power is turned OFF on
standby.

The voice signal from the base unit is output to DSP (98). This signal is led to the headset jack (CN431). The signal through the
headset jack and the other signal output from DSP (97) drives the speaker. When the headset is inserted to the jack, the voice
signal is cut at the jack, so the sound does not come out from the speaker, but from the headset only.