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TK-5220
F400
2.5A
IC400
/SAVE
AVR
/5TC
5RC
IC403
SBC
AVR IC
Q403
SB3 SW
CN400
CN404
IC411
5UC
AVR IC
Q403
SBC
SB2 SW
IC708
AVR IC
IC416
AVR IC
IC407
DC/DC
IC414
Detect
SB1
VOL SW
Q408
AND
D408
OR
Fig. 8 Power supply circuit
16
CIRCUIT DESCRIPTION
TX-RX unit (X57)
+B
RF Final AMP
APC
50C
VCO
50T
Q405
TX circuit
50T SW
50R
Q401
RX circuit
50R SW
50IF
Q402
IF circuit
50IF SW
33C
PLL, VCTCXO
SB3
TX/Busy LED
150C
IC402
Assist, Tune
DC/DC
Control unit (X53)
50U
Universal
SB2
BackLight
Key Light
5A
Option
-10V
IC403
LCD Bias
DC/DC
31BU
Q409
SRAM, RTC
31BU
33M
ASIC, DSP I/O,
IC404
Flach, LCD DRV
AVR
15M
IC717
ASIC, DSP core
DC/DC
33A
ASIC Analog,
IC406
Audio
AVR
/PSW
Q402
IC108
Lvl Conv
ASIC
/BINT
Q401
Lvl Conv
D412
SBC
OR
8. Signaling Circuit
8-1. Encode (QT/DQT/DTMF/2-tone/MSK)
Each signaling data signal of QT, DQT, DTMF, 2-tone
and MSK is generated by the DSP circuit, superposed on
a modulation signal and output from IC108. The modula-
tion balance of the QT/DQT signal is adjusted by the D/A
converter(IC703) and the resulting signal is routed to the
modulation input of the VCO and VCXO (X1). Each deviation
of the TX QT, DQT, DTMF, 2-tone and MSK tone is adjusted
by changing the output level of IC108 and the resulting
signal is routed to the VCO and VCXO. The RX DTMF tone
is routed to the receive audio signal system, and is output
from the speaker.
8-2. Decode (QT/DQT/DTMF/2-tone/MSK)
The audio signal is removed from the FM detection
signal sent to the DSP circuit and the resulting signal is de-
coded.
9. Compander Circuit
The term "compander" means compressor and expand-
er. The compander reduces noise by utilizing a compressor
and an expander. The transceiver contains a DSP (IC102) to
perform this operation. The transceiver compander can be
turned on or off using the FPU.
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