Panasonic KX-TGC450G User manual

Order No.KM42006192CE
Digital Cordless Phone
Digital Cordless Answering System
Model No. KX-TGC450G
KX-TGC460E
KX-TGC460G
KX-TGC462E
KX-TGC462G
KX-TGC463E
KX-TGC463G
KX-TGC464E
KX-TGCA42E
KX-TGCA42EX
B; Black Version
[Version 5.0]
© Panasonic Entertainment & Communication Co., Ltd.
2020-2022
Unauthorized copying and distribution is a violation of law.

This service manual is strictly meant to be used by experienced professional repair technicians only and is not designed
for use by the general public. Products powered by electricity should be serviced and repaired only by experienced
professional repair technicians ("Professionals"). Any attempt to service or repair the product by anyone else could result
in serious injury and even death. Panasonic shall not be responsible, to the extent permitted by applicable law, for any
damages, losses, costs, expenses, death, injury, claims, decree, proceedings, and/or judgement, arising out of,
in connection with, or relating to, any use and/or misuse of this service manual by users other than Professionals.
WARNING
IMPORTANT SAFETY NOTICE
There are special components used in this equipment which are important for safety. These parts are marked by
in the Schematic Diagrams, Circuit Board Diagrams, Exploded Views and Replacement Parts List. It is essential that
these critical parts should be replaced with manufacturer's specified parts to prevent shock, fire or other hazards.
Do not modify the original design without permission of manufacturer.
IMPORTANT INFORMATION ABOUT LEAD FREE, (PbF), SOLDERING
If lead free solder was used in the manufacture of this product, the printed circuit boards will be marked PbF.
Standard leaded, (Pb), solder can be used as usual on boards without the PbF mark.
When this mark does appear, please read and follow the special instructions described in this manual on the
use of PbF and how it might be permissible to use Pb solder during service and repair work.
LWhen you note the serial number, write down all 11 digits. The serial number may be found on the bottom of the unit.
LThe illustrations in this Service Manual may vary slightly from the actual product.

1 Safety Precautions
1.1 Safety Precautions
1. Before servicing, unplug the AC power cord to prevent an electric shock.
2. When replacing parts, use only the manufacturer's recommended components.
3. Check the condition of the power cord. Replace if wear or damage is evident.
4. After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields, etc.
5. Before returning the serviced equipment to the customer, be sure to perform the following insulation resistance test to
prevent the customer from being exposed to shock hazards.
1 Sicherheitsmaßnahmen
1.1.
Sicherheitsmaßnahmen
1. Ziehen Sie vor Reparatur- und Wartungsarbeiten das Netzkabel, um einen elektrischen Schlag zu vermeiden.
2. Verwenden Sie beim Auswechseln von Teilen nur vom Hersteller empfohlene Komponenten.
3. Überprüfen Sie den Zustand des Netzkabels. Ersetzen Sie es, wenn eine Abnutzung oder Beschädigung zu erkennen ist.
4. Achten Sie nach der Durchführung von Reparatur- und Wartungsarbeiten darauf, Kabelanordnung, Isolationsbarrieren,
Isolationspapier, Abschirmungen usw. wieder einzusetzen.
5. Überprüfen Sie unbedingt den Isolationswiderstand wie folgt, bevor Sie das reparierte Gerät an den Kunden
zurücksenden. Auf diese Weise verhindern Sie, dass der Kunde der Gefahr eines elektrischen Schlags ausgesetzt ist.
1.2 For Service Technicians
•Repair service shall be provided in accordance with repair technology information such as service manual so as
to prevent fires, injury or electric shock, which can be caused by improper repair work.
1. When repair services are provided, neither the products nor their parts or members shall be remodeled.
2. If a lead wire assembly is supplied as a repair part, the lead wire assembly shall be replaced.
3. FASTON terminals shall be plugged straight in and unplugged straight out.
•ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover plastic part’s boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on the worktable.
4. Do not touch IC or LSI pins with bare fingers.
•
Reparaturdienste müssen in Übereinstimmung mit den entsprechenden technischen Reparatur-Informationen
(z. B. Serviceanleitung) durchgeführt werden, um die Gefahr von Bränden, Verletzungen oder elektrischen
Stromschlägen zu verhindern, die bei unsachgemäßer Durchführung von Reparaturarbeiten eintreten können.
1. Bei der Durchführung von Reparaturarbeiten dürfen weder die Produkte noch deren Teile oder Komponenten modifiziert
oder umgeformt werden.
2. Wenn eine Kabelbaugruppe als Ersatzteil lieferbar ist, muss diese Kabelbaugruppe komplett erneuert werden.
3. FASTON-Klemmenanschlüsse müssen geradlinig hineingesteckt und geradlinig herausgezogen werden.
•
ICs (Integrated Circuit, integrierte Schaltkreise) und LSIs (Large Scale Integration, großintegrierte Schaltkreise)
können durch statische Elektrizität beschädigt werden.
Die folgenden Vorsichtsmaßnahmen bei der Durchführung von Reparaturen tragen zur Vermeidung von
Fehlfunktionen bei.
Gehäuse der Kunststoffteile mit Aluminiumfolie abdecken.
1.2 Für Servicetechniker
1.
Lötkolben erden.
2.
Arbeitstisch mit leitfähiger Matte abdecken.
3.
IC- oder LSI-Pins nicht mit den bloßen Fingern berühren.
4.
- 3 -

2 Warning
2.1 Battery Caution
Risk of explosion if battery is replaced by an incorrect type.
Dispose of used batteries according to the instructions.
2.1 Vorsichtshinweis zum Akku
2 Warnung
Explosionsgefahr bei Verwendung
nicht geeigneter Akkus.
Entsorgen Sie gebrauchte
Akkus gemäß den Anweisungen.
2.2 About Lead Free Solder (Pbf: Pb free)
Note:
In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that
contains lead.
We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin (Sn),
Silver (Ag), and Copper (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder.
Caution:
•PbF solder has a melting point that is 50°F ~ 70°F (30°C ~ 40°C) higher than Pb solder. Please use a soldering iron with
temperature control and adjust it to 700°F ± 20°F (370°C ± 10°C).
•Exercise care while using higher temperature soldering irons.
•Do not heat the PCB for too long time in order to prevent solder splash or damage to the PCB.
PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100°F (600°C).
When applying PbF solder to double layered boards, please check the component side for excess which may flow onto
the opposite side (See the figure below).
Component
Component
pin
Solder
Remove all of the
excess solder
(Slice View)
- 4 -

Hinweis:
In den unten stehenden Informationen steht Pb, das Symbol für Blei im Periodensystem der Elemente, für bleihaltiges
Standardlötmittel.
Der Begriff PbF-Lötmittel bezieht sich auf das bleifreie Lötmittel, das wir bei unserem Herstellungsprozess verwenden. Es
besteht aus Zinn (Sn), Silber, (Ag) und Kupfer (Cu).
Dieses Modell und andere ähnliche Modelle, die unter Verwendung bleifreien Lötmittels hergestellt wurden, tragen den
PbF-Stempel auf der Platine. Für Wartungs- und Reparaturarbeiten empfehlen wir die Verwendung desselben Lötmitteltyps
vor. Unter Einhaltung einiger Vorsichtsmaßnahmen kann jedoch auch Pb-Standardlötmittel verwendet werden.
V
orsicht
•Der Schmelzpunkt von PbF-Lötmittel ist um 30° ~ 40°C (50° ~ 70°F) höher als der von Pb-Lötmittel. Verwenden Sie bitte
einen Lötkolben mit Temperaturregler, und stellen Sie ihn auf 370° ± 10°C (700 ± 20° F) ein. Falls Sie einen Lötkolben für
hohe Temperaturen verwenden, achten Sie bitte darauf, ihn nicht zu lange zu erhitzen.
• PbF-Lötmittel neigt dazu, zu spritzen, wenn es weit über seinen Schmelzpunkt erhitzt wird, der bei ca. 600°C (1100°F) liegt.
•Wenn Sie Pb-Lötmittel für eine Platine verwenden, die unter Verwendung von PbF-Lötmittel hergestellt wurde, entfernen
Sie bitte möglichst viel des PbF-Lötmittels und stellen Sie sicher, dass verbliebenes PbF-Lötmittel vor dem Auftragen des
Pb-Lötmittels geschmolzen wird.
•Prüfen Sie beim Auftragen von PbF-Lötmittel auf doppelschichtige Platinen bitte die Komponentenseite auf Überschuss,
der auf die gegenüberliegende Seite fließen könnte (siehe Abbildung unten).
2.2. Informationen zum bleifreien Löten (PbF: bleifrei, Pb free)
Komponente
Komponentenstift
Lotmittel
Gesamtes uberschussiges
Lotmittel entfernen
(Schnittansicht)
- 5 -

2.2.1 Suggested PbF Solder
There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper
(Sn+Ag+Cu), you can also use Tin and Copper (Sn+Cu) or Tin, Zinc, and Bismuth (Sn+Zn+Bi). Please check the manufacturer’s
specific instructions for the melting points of their products and any precautions for using their product with
other materials.
The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3 mm, 0.6 mm and 1.0 mm.
0.3 mm X 100 g 0.6 mm X 100 g 1.0 mm X 100 g
Im Fachhhandel sind mehrere Arten von PbF-Lötmittel erhältlich. Dieses Produkt wird unter Verwendung von Zinn, Silber
und Kupfer (Sn+Ag+Cu), you can also use Tin and Copper, (Sn+Cu), or Tin, Zinc, and Bismuth, (Sn+Zn+Bi). Bitte lesen Sie
die besonderen Angaben der Hersteller zu den Schmelzpunkten ihrer Produkte und zu den Vorsichtsmaßnahmen, die bei
der Verwendung ihrer Produkte mit anderen Materialien zu beachten sind.
Die folgenden bleifreien (PbF-)Lötdrähte sind für die Durchführung von Wartungs- und Reparaturarbeiten an diesem
Produkt empfehlenswert: 0,3 mm, 0,6 mm and 1,0 mm.
2.2.1. Empfohlenes PbF-Lötmittel
0.3 mm X 100 g 0.6 mm X 100 g 1.0 mm X 100 g
- 6 -

2.3 Insulation Resistance Test
1. Unplug the AC inlet and connect the two prongs of the plug with a jumper wire.
2. Measure the resistance value with ohmmeter between the jumpered AC plug and all the terminals as shown in following
figures
3. If the measurement is outside the specified limits, there is a possibility of shock hazard. The equipment should be
repaired and rechecked before it is returned to the customer.
Base unit,
Charger,
etc
Exposed
metal part
AC inlet
Ohmmeter
Resistance = more than 10MΩ (at DC 500V, for 2 seconds)
Freiliegendes
Metallteil
Netzstecker
Ohmmeter
Widerstand= größer als 10MΩ (bei Gleichstrom 500V, für 2 Sekunden)
2.3.
Ü
berprüfung des lsolationswiderstands
Basisstation,
Ladegerät,
etc.
1. Ziehen Sie den Netzstecker und überbrücken Sie beide Anschlussstifte mit der Messspitze.
2. Messen Sie den Widerstand zwischen dem Stecker und den freiliegenden Teilen des Metaugehäuses
mit einem Ohmmeter (Schraubenköpfe, Steuerwellen, unterer Rahmen usw).
Hinweis: Einige der freiliegenden Teile können aus Gründen des Designs vom Hauptrahmen isoliert sein.
Bei diesen wird unendlich angezeigt.
3. Wenn die Messung außerhalb der festgelegten Grenzwerte liegt, besteht die Möglichkeit einer Gefährdung
durch einen elektrischen Schlag.
2.4 Discarding of P.C. Board
When discarding P. C. Board, delete all personal information such as telephone directory and caller list or scrap P. C. Board.
Löschen Sie zur Entsorgung der Leiterplatte alle persönlichen Daten wie z. B. das Telefonbuch und die Anruferliste, oder
verschrotten Sie die Leiterplatte.
2.4. Entsorgung der Leiterplatte
- 7 -

2.5 Disposal of Old Equipment and Batteries (Only for European Union and
countries with recycling systems)
These symbols ( )on the products, packaging, and/or accompanying documents mean
that used electrical and electronic products and batteries must not be mixed with general household
waste. For proper treatment, recovery and recycling of old products and batteries, please take
them to applicable collection points in accordance with your national legislation. By disposing of
them correctly, you will help to save valuable resources and prevent any potential negative effects
on human health and the environment. For more information about collection and recycling,
please contact your local municipality. Penalties may be applicable for incorrect disposal of this
waste, in accordance with national legislation.
For business users in the European Union
If you wish to discard electrical and electronic equipment, please follow local environmental
regulation.
Information on Disposal in other Countries outside the European Union
These symbols ( ) are only valid in the European Union. If you wish to discard these items,
please contact your local administration and ask for the correct method of disposal.
Note for the battery symbol
This symbol ( ) might be used in combination with a chemical symbol. In this case it complies
with the requirement set by the Directive for the chemical involved.
1 2
1, 2
1, 2
2
- 8 -

Entsorgung von Altgeräten und Batterien (Nur für die Europäische Union
und Länder mit Recyclingsystemen)
1 2
Diese Symbole ( 1, 2) auf den Produkten, der
Verpackung und/oder den Begleitdokumenten,
bedeutet, dass gebrauchte elektrische und
elektronische Produkte sowie Batterien nicht in den
allgemeinen Hausmüll gegeben werden dürfen. Bitte
führen Sie alte Produkte und verbrauchte Batterien zur
Behandlung, Aufarbeitung bzw. zum Recycling gemäß
den gesetzlichen Bestimmungen den zuständigen
Sammelpunkten zu.
Indem Sie diese Produkte und Batterien
ordnungsgemäß entsorgen, helfen Sie dabei, wertvolle
Ressourcen zu schützen und eventuelle negative
Auswirkungen auf die menschliche Gesundheit und die
Umwelt zu vermeiden.
Für mehr Informationen zu Sammlung und
Recycling, wenden Sie sich bitte an Ihren
örtlichen Abfallentsorgungsdienstleister. Gemäß
Landesvorschriften können wegen nicht
ordnungsgemäßer Entsorgung dieses Abfalls
Strafgelder verhängt werden.
Für geschäftliche Nutzer in der
Europäischen Union
Wenn Sie elektrische oder elektronische Geräte
entsorgen möchten, wenden Sie sich wegen
genauerer Informationen bitte an Ihren Händler oder
Lieferanten.
Informationen zur Entsorgung in
Ländern außerhalb der Europäischen
Union
Diese Symbole ( 1, 2) gelten nur innerhalb der
Europäischen Union. Wenn Sie solche Gegenstände
entsorgen möchten, erfragen Sie bitte bei den
örtlichen Behörden oder Ihrem Händler, welches die
ordnungsgemäße Entsorgungsmethode ist.
Hinweis zum Batteriesymbol
Dieses Symbol ( 2) kann in Kombination mit einem
chemischen Symbol verwendet werden. In diesem Fall
erfüllt es die Anforderungen derjenigen Richtlinie, die
für die betreffende Chemikalie erlassen wurde.
2.5
- 9 -

3 Specifications
●Dimensions (W x D x H):
Base unit: Approx. 106 mm x 87 mm x 63 mm
Handset: Approx. 48 mm x 32 mm x 165 mm
Charger unit: Approx. 71 mm x 70 mm x 42 mm
Mass (Weight):
Base unit (*1): Approx. 90 g
Base unit (*2): Approx. 120 g
Handset: Approx. 130 g
Charger: Approx. 40 g
●Standard:
DECT (Digital Enhanced Cordless
Telecommunications),
GAP (Generic Access Profile)
●Frequency range:
1.88 GHz to 1.90 GHz
●RF transmission power:
Approx. 10 mW (average power per
channel)
250 mW (max.)
●Power source:
100–240 V AC, 50/60 Hz
●Power consumption:
Base unit:
Standby: 0.5 W
Maximum: 2.5 W
Charger:
Standby: 0.1 W
Maximum: 1.5 W
●Operating conditions:
0 °C–40 °C, 20 %–80 % relative air
humidity (dry)
●
●
(*1) KX-TGC450
(*2) KX-TGC460
●Rechargeable battery:
AAA (R03) Ni-MH battery (1.2 V, 550 mAh)
Note:•Design and specifications are subject to change without notice.
- 10 -

4 Technical Descriptions
4.1 Block Diagram (Base Unit_Main)
KX-TGC450/460 BLOCK DIAGRAM (BASE UNIT)
Operational P.C. Board
ANS_LED
KEYS
MSG_LED
KEY 1 3
KEY C, D, E
Q651, Q652
*1
*1
*1 : for KX-TGC460 only
D101
CHARGE_CONTACT
+
-
SP
X501
13.824 MHz
ANT1
TEL JACK
L1T L1R DCP DCM
DC JACK
RLY
SIDE TONE CIRCUIT
Q161
Q141
BELL
DETECT
HOOK
BELL
Q111
LIN
LOUT
RF_PART
HSMIP
HSMIN
IC501
BBIC
INUSE
DETECT 2
RECEIVE AMP
DCIN 1 DCIN 2
IC302
VCCPA
VBAT_APU
VBAT
VCC_FE
VCC_IF
VCC_VCO
3.0V
DOUBOUT
SCL, SDA
WP
IC611
EEPROM MEMORY
R151,R152
Q171
VBAT
SPOUTN
SPOUTP
3.0 V
REGULATOR
STM/CKM
R371 R372
VCCA
VCC
XIN
XOUT
LINE
DETECT
DCIN 3
Optional POWER SUPPLY CIRCUIT FROM HS Q351, Q352
FLASH *1 MEMORY
IC601
VDD
CLK, DO
DL,CS
RXp RXn TXp TXn
RESET
RSTN
- 11 -

4.2 Block Diagram (Base Unit_RF Part)
RXp
RXn
ANT1
TXp
TXn
- 12 -

4.3 Circuit Operation (Base Unit)
General Description:
(BBIC, Flash Memory, EERROM) is a digital speech/signal processing system that implements all the functions of speech
compression, record and playback, and memory management required in a digital telephone answering machine.
The BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functions as
follows.
RF part
ADPCM
Analog
Front
End
&
Multi-
plexer
TEL
Line
Interface
Digital
Speech
Processor
Caller ID
Modem
Digital TAM System
Flash Memory IC601
Host CPU
BBIC (IC501)
TDD & TDMA
with FHSS
Processor ADPCM
Keys/ LEDsEEPROM IC611
*1 for KX-TGC460 only
*1 *1
*1
4.3.1 BBIC (Base Band IC: IC501)
•DTMF Generator
When the DTMF data from the handset is received, the DTMF signal is output.
•Synthesized Voice (Pre-recorded message)
The BBIC implements synthesized Voice, utilizing the built in speech detector and a Flash Memory, which stored the
vocabulary.
•Caller ID demodulation
The BBIC implements monitor and demodulate the FSK/DTMF signals that provide CID information from the Central
Office.
•Digital Switching
The voice signal from telephone line is transmitted to the handset or the voice signal from the handset is transmitted to
the Telephone line, etc. They are determined by the signal path route operation of voice signal.
•Block Interface Circuit
RF part, LED, Key scan, Speaker, Telephone line.
4.3.2 Flash Memory (IC601)(for KX-TGC460 only)
Following information data is stored.
•Voice signal
ex: Pre-recorded Greeting message, Incoming message
4.3.3 EEPROM (IC611)
Following information data is stored.
•Settings
ex: message numbers, ID code, Flash Time, Tone/Pulse
- 13 -

4.3.4 Power Supply Circuit/Reset Circuit
The power supply voltage from AC adaptor is converted to VBAT (3.0V) in IC302. And +3.0V for peripherals and analog part is
insulated from VBAT by Doubler of BBIC.
Circuit Operation:
5.5V
VBAT
RSTN(Reset)
pin 54
VBAT
pin 10
pin 57
pin 9
pin 15
IC501
IC302 IC601
BBIC
DOUBLER OUT
For peripherals
VDDC (1.2V)
AC Adaptor 3.0V
REGULATOR
FLASH
IC611
EEPROM
+3.0V
STM/CKM
Receive
Amp.
RF Part
ANS LED
MSG LED
Startmonitor
(IC501 57pin)
VDDC (1.2 V)
VBAT
Reset (RSTN)
(IC501_54 pin)
BBIC chip initialize
(CKM/STM)
Q171
- 14 -

4.3.4.1 Charge Circuit
The voltage from the AC adaptor is supplied to the charge circuits.
R372 R371
F301 DCP
+5.5V
CHARGE-
CHARGE+
DCM
D362
C351
!
- 15 -

4.3.5 Telephone Line Interface
Telephone Line Interface Circuit:
Function:
•Bell signal detection
•ON/OFF hook and pulse dial circuit
•Side tone circuit
Bell signal detection and OFF HOOK circuit:
In the idle mode, Q141 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the Tip (T)
and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows:
T →R111 →C110 →Q111 →BBIC pin 5 [BELL]
When the CPU (BBIC) detects a ring signal, Q141 turns on, thus providing an off-hook condition (active DC current flow
through the circuit). Following signal flow is the DC current flow.
T →D101 →Q141 →Q161 →R163 →D101 →P101 →R.
ON HOOK Circuit:
Q141 is open, Q141 is connected as to cut the DC loop current and to cut the voice signal. The unit is consequently in an onhook
condition.
Pulse Dial Circuit:
Pin 6 of BBIC turns Q141 ON/OFF to make the pulse dialing.
Side Tone Circuit:
Basically this circuit prevents the TX signal from feeding back to RX signal. As for this unit, TX signal feed back from Q161 is
canceled by the canceller circuit of BBIC.
PULSE_MUTE
BELL
HOOK
NL_CID
R121 390k
R122 390k
C120
1000p
+3.0V
+3.0V
C331
NC
VDDC
L2R
L1R
L1T
L2T
*R123
NC
*R124
10
*Q140
R141
100k
R142
2.7k
*R144 NC
C143N
C
C142
0.01u
Q161
C152 0.01u
*C164 0.1u
C181
NC
R117 100k
R115
5.6M
R116
5.6M
R118 100k C115 100n C116 100n
*Q141
Q111
D133 D132
D113
C161 10u
*C166
NC
C178 0.1u
Q171
*C141 NC
R114
68k
*R148
10k
*R149
680
*R162
NC
R165
27k
C113
0.01u
0
7
206
1
R*
*R159
1.5k
4
6
1R*
k2.2
k
1
771
R
R113
22k
R111
1M
R112
47k
*C167
2700p
R158
4.7k
RA151
1k
1
23
4
C101 680p
C102 680p
C121 680p
C122 680p
D101
1
43
2
R176
1k
C103 NC *C104
NC
*R103
1.2k
R163
39(0.5W)
GAP
1
2
C110 0.1u
C112 0.1u
R171
220
R172 680k
R175
3.9k
*R104
NC
R167
NC
C173
0.027u
C175
560p
*D142
SA102
NC
21
*SA101
21
P101
C176 1u
R151 100k
R152 130k
D143
NC
L101
27n
C476 NC
*C475 10pF
2
41
Q
481
C
u1
C507 2.2u
*D141
R131 NCR133 NC
C132 NC
*R154
NC
*R153
NC
*Q144
NC
*C479 10pF
*R169
39k
*R145 2.2k
*C171
0.033u
DC Monitor
Caller ID
Bell detection
Pin 28 of IC501 Pin 25 of IC501 Pin 24 of IC501
Pin 16 of IC501 Pin 18 of IC501
Pin 19 of IC501 Pin 17 of IC501
Pin 6 of IC501
Pin 5 of IC501
HOOK
BELL
- 16 -

4.3.6 Transmitter/Receiver
●Audio Circuits and DTMF tone signal circuits.
Base Unit and Handset mainly consist of RF Module and DECT BBIC.
Base Unit and Handset transmit/receive voice signal and data signal through the antenna on carrier frequency.
Signal Path:
*Refer to [4.6 Signal Route].
4.3.6.1 Transmitter Block
The voice signal input from the TEL LINE interface goes to DECT BBIC (IC501) as shown in [4.1 Block Diagram (Base
Unit_Main)].
The voice signal passes through the analog part of IC501 where it is amplified and converted to a digital audio stream signal.
The burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to produce
the GAP (Generic Access Profile) standard DECT frame, assigning to a time slot and channel etc.
In IC501, the carrier frequency is changing, and frequency modulated RF signal is generated.In IC501,RF signal is amplified, and
radiated from antenna. Handset detects the voice signal or data signal in the circuit same as the following explanation of Receiver
Block.
4.3.6.2 Receiver Block
The signal of 1900 MHz band which is input from antenna is input to IC501 as shown in [4.1 Block Diagram (Base Unit_Main)].
In IC501, the signal of 1900 MHz band is downconverted to 864 kHz signal and demodulated, as GAP (Generic Access Profile)
standard DECT frames. It passes through the decoding section burst switch controller where it separates out the frame
information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where it is turned back
into analog audio. This is amplified by the analog front end, and goes to the TEL LINE Interface.
- 17 -

4.4 Block Diagram (Handset)
QSPI FLASH MEMORY
IC4
Reset
Reset Pin 71
SPEAKER
RECEIVER
MIC
CHARGE CIRCUIT Q2, Q3, Q4, Q9, R8
CHARGE CONTACTS
CHARGE(+)
CHARGE_CTRL
CHARGE_DET
BATTERY TERMINAL R45
VBAT
BATT-
1.8 V
Q1
1.8 V
LCD
CD
RESET
CS SID
SCL
CPU
Analog
Front
End
D/A A/D
35 37
21 22
17 18
34 33
32
24
44 45
73 63 64 77 76
ADPCM
Codec
Filter
DSP
Speech
Decoding
Speech
Encoding
BMC
Burst
Decoding
ANT1
Burst
Encoding
RF
PLL
MOD/DEMOD
1 2
87 86
RXn ANT1 RXp
TXp TXn
7
8
XTAL
X1
10.368 MHz
BATTERY
46
ON SWITCH
KEYPAD
Charge
Pump
ROWS
COLUMNS
CP3V
CP4V
57, 58, 59, 60
11, 12, 13, 14, 25, 55
47, 48, 51, 53 QSPI-IO 0-3
BBIC
IC1
65
LCD-BACK LIGHT
KEY LED 61
LDO_CTRL
1.8 V
CP3V
QSPI
Control
52 QSPI-SCK
49 QSPI-CS
LCD_LED0
CP4V
CP3V
1.8 V
GND
KX-TGCA42 BLOCK DIAGRAM (HANDSET)
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4.5 Circuit Operation (Handset)
4.5.1 Outline
Handset consists of the following ICs as shown in [4.4 Block Diagram (Handset)].
●DECT BBIC (Base Band IC): IC1
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, EEPROM, LCD, RF Power Amp.)
- PLL Oscillator
- Detector
- Compress/Expander
- Reception
- Integrated 1.9 GHz PA for DECT
●QSPI FLASH MEMORY: IC4
- Main Program D/L Area
- Following information data is stored
- Setting.
- ex: ID code, user setting
4.5.2 Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: BATT+) →Q1 (1.8 V), IC1-44pin (CP3V)
The Reset signal generates IC1 (71 pin) and 1.8 V.
1.8V
Battery +
Reset
(IC1_71 pin)
4.5.3 Charge Circuit
Circuit Operation:
When the handset is charged on the Base Unit, the charge current flow as follows;
DC+(5.5 V) →R371 →D362 →CHARGE+(Base) →CHARGE+(Handset) →Q2 and R2 →Q3 →BATTERY+... Battery...
BATTERY- →R45 →GND →CHARGE-(Handset) →CHARGE-(Base) →GND →DC-(GND)
In this way, the BBIC on Handset detects that the battery is charged.
The charge current is controlled by switching Q9 of Handset.
Refer to Fig.101 in [4.5.2 Power Supply Circuit/Reset Circuit]
4.5.4 Battery Low/Power Down Detector
Circuit Operation:
“Battery Low” and “Power Down” are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
●Battery Low.
Battery voltage: V(Batt) 2.25 V ± 50 mV
The BBIC detects this level and " " starts flashing.
●Power Down.
Battery voltage: V(Batt) 2.0 V ± 50 mV
The BBIC detects this level and power down.
4.5.5 Speakerphone
The hands-free loudspeaker at SP+ and SP- is used to generate the ring alarm.
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4.6 Signal Route
Note:
: inside of Handset
*1: KX-TGC460 only
*1
*1
*1
*1
IC601 - IC501(73/74 - 28) - L101 - C184 - Q161 - Q141 - D101 - P101
- T/R(TEL LINE)
T/R(TEL LINE) - P101 - D101 - Q141 - Q161 - R164 - R177- C173 - Q171 - C178
IC601 - IC501(73/74 - 29/31) - SPEAKER
IC501(28) - L101 - C184 - Q161 - Q141 - D101 - P101 - T/R(TEL LINE)
T/R(TEL LINE) - P101 - C121/C122 - R121/R122 - IC501(24/25)
T/R(TEL LINE) - P101 - R111/R112 - C110/C112 - Q111 - IC501(5)
HANDSET TX
HANDSET RX
HANDSET
SP-Phone TX
HANDSET
SP-Phone RX
SIGNAL ROUTE IN 䊻㻌 ROUTE 䊻㻌 OUT
GREETING
RECORDING
GREETING PLAY
TO TEL LINE
ICM RECORDING
ICM PLAY TO
SPEAKER
DTMF SIGNAL
TO TEL LINE
CALLER ID
BELL DETECTION
MIC (+) module (56)
MIC (–)
ANT to BASE
MIC (+)
MIC (–)
module (9)
module (36)
Ant 1 module (36) Rcv +
module (13)
module (12) Rcv -
MIC (+) module (56)
MIC (–)
ANT to BASE
module (9)
module (36)
module (36) SP +
module (17)
module (18) SP -
module (56)
module (9)
module (36) ANT to BASE
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