Kenwood NX-210(G) Service Manual page 17

F201
2.5A
IC204
/SAVE
AVR
/5TC
50T SW
5RC
50R SW
IC207
SBC
AVR IC
Q201
SB2 SW
DC/DC
IC205
AVR IC
DC/DC
IC818
5UC
AVR IC
IC210
AVR IC
IC206
DC/DC
IC209
Detect DC/DC
SB1
Lvl Conv
VOL SW
Q207
Lvl Conv
AND
D209
SBC
OR
5A
CN321
Sub (GPS) unit (X58)
CN10
IC4
31V GPS module
AVR IC
Buffer
V_BCKP
Lithium cell
Fig. 8 Power supply circuit
CIRCUIT DESCRIPTION
TX-RX unit (X57)
+B RF Final AMP
APC
50C
VCO
50T
Q206
TX circuit
50R
Q205
RX circuit
33C PLL, VCTCXO,
GPS LNA
Back Light
SB2
Key Light
TX/Busy LED
150C
IC211
Assist, Tune
5A
Option
–10V
IC105 (X53)
LCD Bias
50U
Universal
31BU
Q208
SRAM, RTC
31BU
33M ASIC, DSP I/O,
IC203
Flash, LCD DRV
AVR
15M
IC202
ASIC, DSP core
33A ASIC Analog,
IC201
Audio
AVR
/PSW
Q203
/BINT
Q204
IC309
ASIC
D212
OR
8. Signaling Circuit
8-1. Encode (QT/DQT/LTR/DTMF/2-tone/MSK)
Each signaling data signal of QT, DQT, LTR, DTMF,
2-tone and MSK is generated by the DSP circuit, super-
posed on a modulation signal and output from IC309. The
modulation balance of the QT/DQT/LTR signal is adjusted by
the D/A converter (IC801) and the resulting signal is routed
to the modulation input of the VCO and PLL (IC503). Each
deviation of the TX QT, DQT, LTR, DTMF, 2-tone and MSK
tone is adjusted by changing the output level of IC309 and
the resulting signal is routed to the VCO and IC503. The RX
DTMF tone is routed to the receive audio signal system, and
is output from the speaker.
8-2. Decode (QT/DQT/LTR/DTMF/2-tone/MSK)
The audio signal is removed from the FM detection signal
sent to the DSP circuit and the resulting signal is decoded.
9. Compander Circuit
The term "compander" means compressor and expander.
The compander reduces noise by utilizing a compressor
and an expander. The transceiver contains a DSP (IC304) to
perform this operation. The transceiver compander can be
turned on or off using the FPU.
10. GPS Circuit
The GPS information function can be used by setting it
through the FPU. When the GPS information function is
enabled, the AVR (IC4/GPS) is enabled by the OPT5, and is
supplied to the GPS circuit.
The GPS circuit block consists of a TX-RX unit and
a GPS unit (X58). The circuit from an antenna to LNA is on
a TX-RX unit. This output is connected to the GPS unit by
the coaxial cable.
The GPS signal of 1575.42MHz received with the an-
tenna (with GPS band) is passed by the HPF and BPF (L17/
TX-RX) and is amplifi ed by the LNA (IC11/TX-RX).
The GPS signal is processed by the GPS IC (IC1/GPS)
and input to the ASIC (IC309/TX-RX) through the UART
port. The ASIC (IC309/TX-RX) processes the GPS data
(NMEA) and sends the resulting information to the LCD.
The GPS IC operates in stand-alone. Operating voltage
is 3.1V. When the transceiver power is off, the GPS IC will
be backed up with the internal coin battery. When the battery
pack is removed, the GPS IC will be backed up for about
one day in a coin battery. But if the GPS IC has never had
the position fi xed, it will not be backed up.
NX-210(G)
17