Panasonic KX-FC253UA-T / KX-FC258RU-T Service Manual ▷ View online
49
KX-FC253UA-T/KX-FC258RU-T
6.13. Cordless Handset
6.13.1. Block Diagram
SPEAKER
RECEIVER
MIC
CN4
Headset
CHARGE
CIRCUIT
CIRCUIT
Q4,Q5,Q9
R7
R7
CHARGE
CONTACTS
CONTACTS
CHARGE(+)
CHARGE(-)
CHARGE
CHARGE DETECT
EEPROM
SCL
SDA
SWITCHED
SUPPLY
SUPPLY
Q1
Q1
BATTERY
TERMINAL
TERMINAL
D7
VBAT1
DC/DC-SWITCH
J1
J2
2.5V
Q3
Q3
1.8V
Q2
Q2
4.0V
2.5V
1.8V
LCD
CD
RESET
CSB
SDA
SCL
CPU
Analog
Front
End
D/A
A/D
30
32
66
67
72
72
62
52
45
44
58
56
59
60
6
47
46
77
ADPCM
Codec
Filter
DSP
Speech
Decoding
Speech
Encoding
BMC
Burst
Decoding
Burst
Encoding
RF
Interface
RF
Module
IC4
23
22
RXDA
TXDA
19
26
25
24
RSSI
SYDA
SYEN
SYCL
SYEN
SYCL
16
17
XTAL
X1
X1
10.368
MHz
MHz
BATTERY
61
ON SWITCH
KEYPAD
ROWS
COLUMNS
1,12,40,76
27,28,34,35,36,74
BBIC
IC1
IC3
11
LCD-BACK LIGHT
KEY-BACK LIGHT
Ringer LED
5
75
9
1
2
3
4
5
2
3
4
5
KX-FC253UA-T / KX-FC258RU-T: CORDLESS HANDSET BLOCK DIAGRAM
50
KX-FC253UA-T/KX-FC258RU-T
6.13.2. Circuit Operation (Cordless Handset)
6.13.2.1. Outline
Handset consists of the following ICs as shown in Block Diagram (P.49).
• 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)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, EEPROM, LCD)
• RF Module: IC4
- PLL Oscillator
- Detector
- Compress/Expander
- Amplifier for transmission and reception
- Detector
- Compress/Expander
- Amplifier for transmission and reception
• EEPROM: IC3
- Temporary operating parameters (for RF, etc.)
6.13.2.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: J1)
BATTERY(2.2 V ~ 2.6 V: J1)
→ F1, L1, D1 → Q2 (1.8 V), Q3 (2.5 V), Q1 (4.2 V)
The Reset signal generates IC1 (53 pin) and 1.8 V.
6.13.2.3. Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DC+(6.5V)
DC+(6.5V)
→ R55, R56 → CHARGE+(Base) → CHARGE+(Handset) → L4 → Q4 → D7→ F1 → BATTERY+ ... Battery ...
BATTERY-
→ R45 → GND → CHARGE-(Handset)→ CHARGE-(Base) → GND → DC-(GND)
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q5 of Handset.
The charge current is controlled by switching Q5 of Handset.
6.13.2.4. 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;
The detected voltage is as follows;
• Battery Low
Battery voltage: V(Batt) 2.25V ± 50mV
The BBIC detects this level and "
The BBIC detects this level and "
" starts flashing.
• Power Down
Battery voltage: V(Batt) 2.00V ~ 2.05V
The BBIC detects this level and power down.
The BBIC detects this level and power down.
6.13.2.5. Speakerphone
The hands-free loudspeaker at SP+ and SP- works as a ringer/alarm as well.
6.13.3. Circuit Operation (Charger Unit)
6.13.3.1. Power Supply Circuit
The power supply is as shown.
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KX-FC253UA-T/KX-FC258RU-T
7 Location of Controls and Components
7.1.
Overview
7.1.1.
Base Unit
(1) Document guides
(2) Paper tray
(3) Metal recording paper guide
(4) Paper support
(5) Recording paper exit
(6) Recording paper entrance
(7) Antenna
(8) Microphone
(9) Front cover
(10) Document entrance
(11) Document exit
(12) Speaker
(13) Green button (Back cover release button)
(14) Back cover
(2) Paper tray
(3) Metal recording paper guide
(4) Paper support
(5) Recording paper exit
(6) Recording paper entrance
(7) Antenna
(8) Microphone
(9) Front cover
(10) Document entrance
(11) Document exit
(12) Speaker
(13) Green button (Back cover release button)
(14) Back cover
7.1.2.
Cordless Handset
(1) Charge indicator
Ringer indicator
Message indicator
(2) Receiver
(3) Microphone
(4) Headset socket
(5) Speaker
Ringer indicator
Message indicator
(2) Receiver
(3) Microphone
(4) Headset socket
(5) Speaker
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KX-FC253UA-T/KX-FC258RU-T
7.2.
Control Panel
7.2.1.
Base Unit
(1) [MIC] (Microphone)
• The built-in microphone.
(2) [GREETING REC]
• To record a greeting message.
(3) [GREETING CHECK]
• To check a greeting message.
(4) [MEMO]
• To record a memo message.
(5) [ERASE]
• To erase messages.
(6) [AUTO ANSWER]
• To turn the auto answer setting ON/OFF.
(7) [PLAYBACK]
• To play messages.
(8) [REDIAL] [PAUSE]
• To redial the last number dialed from the base unit.
• To insert a pause during dialing.
• To insert a pause during dialing.
(9) [R (FLASH)]
• To access special telephone services or for transferring
extension calls.
• The recall/flash time can be changed (feature #72).
(Refer to Program Mode Table (P.104).)
(10) [ABH] (for KX-FC253UA-T)
• To use Caller identification features.
(10) [AOH] (for KX-FC258RU-T)
• To use Caller identification features.
(11) [STOP]
• To stop an operation or programming session.
• To erase a character/number. Press and hold to erase all
• To erase a character/number. Press and hold to erase all
characters/numbers.
(12) [LOCATOR] [INTERCOM]
• To make/answer intercom calls.
• To page or locate a cordless handset.
• To page or locate a cordless handset.
(13) [PRINT REPORT]
• To print lists and reports for reference purposes.
(14) [MENU]
• To start or exit programming.
(15) [PHONEBOOK] [VOLUME]
• To adjust volume.
• To search for a stored item.
• To search for a stored item.
(16) [SET]
• To store a setting during programming.
(17) [TONE]
• To change from pulse to tone temporarily during dialling
when your line has rotary pulse service. You can also use
tone dial service by changing feature #13 on Program
Mode Table (P.104).
tone dial service by changing feature #13 on Program
Mode Table (P.104).
(18) [MUTE]
• To mute your voice during a conversation. Press again to
resume the conversation.
(19) [SP-PHONE]
• For speakerphone operation.
(20) [FAX START]
• To send or receive a fax.
(21) [COPY]
• To copy a document.
7.2.2.
Cordless Handset
(1) Soft keys
• To select the features or operations displayed directly above
each key.
(2)
(TALK)
• To make/answer calls.
(3) Navigator
• To adjust volume.
• To search for a stored item.
• To select features or feature settings during programming.
• To navigate to the next operation.
• To search for a stored item.
• To select features or feature settings during programming.
• To navigate to the next operation.
(4)
(Speakerphone)
• For speakerphone operation.
(5) [R] (Recall)
• To access special telephone services or for transferring
extension calls.
• The recall/flash time can be changed (feature #72).
(Refer to Cordless Handset Programming (P.61).)
(6)
(Off/Power)
• To turn power ON/OFF.
• To hang up.
• To stop an operation or programming.
• To hang up.
• To stop an operation or programming.
(7)
(Clear/Mute)
• To mute your voice during a conversation. Press again to
resume the conversation.
• To erase a character/number. Press and hold to erase all
characters/numbers.
(8) [INT] (Intercom)
• To page or locate the base unit or another cordless handset.
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