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Model
KX-TS2368CAW
Pages
43
Size
2.32 MB
Type
PDF
Document
Service Manual
Brand
Device
Telephone / INTEGRATED TELEPHONE SYSTEM
File
kx-ts2368caw.pdf
Date

Panasonic KX-TS2368CAW Service Manual ▷ View online

21
KX-TS2368CAW
10.4.2. Speakerphone IC Data (IC601)
9
4
5
MIC
AMP
TRANSMIT
ATTENUATOR
15
27
16
7
18
24
SPEAKER
AMP
RECEIVE
ATTENUATOR
TRANSMIT
LEVEL
DETECTOR
RECEIVE
LEVEL
DETECTOR
Vcc
REGULATOR
TRANSMIT
RECEIVE
COMPARATOR
ATTENUATOR
CONTROL
SIGNAL
NOISE
DETECTOR
PEAK
LIMITER
SPEAKERPHONE
IC SYSTEM MC34018
RECEIVE CHANNEL
TRANSMIT CHANNEL
Pin 
NO.
Name
Description
1
RR
A resistor to ground provides a reference current for the transmit and receive attenuators.
2
RTX
A resistor to ground determines the nominal gain of the transmit attenuator. The transmit channel gain is inversely proportional to
the RTX resistance.
3
TXI
Input to the transmit attenuator. Input resistance is nominally 5.0 kohms.
4
TXO
"Output to the transmit attenuator. The TXO output signal drives the input of the transmit level detector, as well as the external cir-
cuit which drives the telephone line."
5
TLI
Input of the transmit level detector. An external resistor ac coupled to the TLI pin sets the detection level. Decreasing this resistor
increases the sensitivity to transmit channel signals.
6
TLO
Output of the transmit level detector. An external resistor and capacitor set the time the comparator will hold the system in the
transmit mode after speech ceases.
7
RLI
Input of the receive level detector. An external resistor ac coupled to the RLI pin sets the detection level. Decreasing this resistor
increases the sensitivity to receive channel signals.
8
RLO
Output of the receive level detector. An external resistor and capacitor set the time the comparator will hold the system in the
receive mode after the receive signal ceases.
9
MCI
Microphone amplifier input. Input impedance is nominally 10 kohms and the dc bias voltage is approximately equal to VB.
10
MCO Microphone amplifier output. The mic amp gain is internally set at 34 dB (50 V/V).
11
CP1
A parallel resistor and capacitor connected between this pin and Vcc holds a voltage corresponding to the background noise level.
The transmit detector compares the CP1 voltage with the speech signal from CP2.
12
CP2
A capacitor at this pin peak detects the speech signals for comparison with the background noise level held at CP1.
13
XDI
Input to the transmit detector system. The microphone amplifier output is ac coupled to the XDI pin through an external resistor.
14
SKG High current ground pin for the speaker amp output stage. The SKG voltage should be within 10 mV of the ground voltage at pin
22.
15
SKO Speaker amplifier output. The SKO pin will source and sink up to 100 mA when ac coupled to the speaker. The speaker amp gain
is internally set at 34 dB (50 V/V).
16
V+
Input dc supply voltage. V+ can be powered from Tip and Ring if an ac decoupling inductor is used to prevent loading ac line sig-
nals. The required V+ voltage is 6.0 to 11 V (7.5 V nominal) at 7.0 mA.
17
AGC "A capacitor from this pin to VB stabilizes the speaker amp gain control loop
18
CS
"Digital chip select input. When at a Logic ""0"" (<0.7 V) the Vcc regulator is enabled. When at a Logic ""1"" (>1.6 V)
19
SKI
Input to the speaker amplifier. Input impedance is nominally 20 kohms.
20
Vcc
"A 5.4 V regulated output which powers all circuit expect the speaker amplifier output stage. Vcc can be used to power external cir-
cuitry such as a microprocessor (3.0 mA max). A filter capacitor is required. The MC 34018 can be powered by a separate regu-
lated supply by connecting V+ and Vcc to a voltage between 4.5 V and 6.5 V while maintaining CS at a Logic ""1""."
21
VB
An output voltage equal to approximately Vcc/2 which serves as an analogue ground for the speakerphone system. Up to 1.5 mA
of external load current may be sourced from VB. Output impedance is 250 ohms. A filter capacitor is required.
22
Gnd
Ground pin for the IC (except the speaker amplifier).
23
XDC "Transmit detector output. A resistor and capacitor at this pin hold the system in the transmit mode during pauses between words
or phrases. When the XDC pin voltage decays to ground
24
VLC
Volume control input. Connecting this pin to the slider of a variable resistor provides receive mode volume control. The VLC pin
voltage should be less than or equal to VB.
25
ACF
Attenuator control filter. A capacitor connected to this pin reduces noise transients as the attenuator control switches levels of
attenuation.
26
RXO Output of the receive attenuator. Normally this pin is ac coupled to the input of the speaker amplifier.
27
RXI
Input of the receive attenuator. Input resistance is nominally 5.0 kohms.
28
RRX A resistor to ground determines the nominal gain of the receive attenuator. The receive channel gain is directly proportional to the
RRX resistance.
22
KX-TS2368CAW
10.4.3. Ringer IC (IC1,IC22)
Vcc 1
RSL 2
LFI 3
LFO 4
OUT
8
HFI
7
HFO
6
GND
5
LOW FREQ
OSC
HIGH FREQ
OSC
POWER SUPPLY
WITH
HYSTERISIS
AMP
Pin descriptions
1
2
3
4
5
6
7
8
Vcc
RSL
LFI
LFO
GND
HFO
HFI
OUT
Pin No. Pin name
Power supply pin
   RSL pin
Low-frequency time
constant connector pin
 GND pin
High-frequency time
constant connector pin
Output pin
This is the power supply pin for the lC. It is connected to the (     ) pin of the diode bridge.
This is used to change the operation initiation current when connected to the GND pin.
This is connected to the time constant that determines the oscillation frequency
on the warble.
This pin has the lowest potential on the lC. It is connected to the (     ) pin of the diode bridge.
This is connected to the time constant that determines the oscillation frequency
on the tone side (the audible frequency side).
This is used to connect a piezoelectric buzzer, or to connect a dynamic speaker through a 
transformer.
Name
Function
23
KX-TS2368CAW
10.5. Module Block Diagram
10.5.1. LCD Module Block
10.5.2. Connector Pin Assignment
Pin No.
Signal
Function
Enable
1
VDD
Power Supply (5V)
2
VLCD
LCD Power Input
3
VSS
Power Gnd (0V)
4
DATA
Serial Data Input
H/L
5
WR
Write Data
 H
6
CS
Chip Selection
Low Active
(1) VDD
LCD
32.768kHz
Crystal
HT1621 CONTROLLER
OR EQUIVALENCE
SEG 32
COM 4
(2) VLCD
(3) VSS
(4) DATA
(5) WR
(6) CS
24
KX-TS2368CAW
10.6. How to Replace the Flat Package IC
Even if you do not have the special tools (for example, a spot heater) to remove the Flat IC, with some solder (large amount), a
soldering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
10.6.1. Preparation
• PbF (: Pb free) Solder
• Soldering Iron
Tip Temperature of 700 
F ± 20 F (370 C ± 10 C)
Note: We recommend a 30 to 40 Watt soldering iron. An expert may be able to use a 60 to 80 Watt iron where someone with
less experience could overheat and damage the PCB foil.
• Flux
Recommended Flux: Specific Gravity 
 0.82.
Type 
 RMA (lower residue, non-cleaning type)
Note: See About Lead Free Solder (Pbf: Pb free) (P.4)
10.6.2. How to Remove the IC
1. Put plenty of solder on the IC pins so that the pins can be completely covered.
Note:
If the IC pins are not soldered enough, you may give pressure to the P.C. board when cutting the pins with a cutter.
2. Make a few cuts into the joint (between the IC and its pins) first and then cut off the pins thoroughly.
3. While the solder melts, remove it together with the IC pins.
When you attach a new IC to the board, remove all solder left on the board with some tools like a soldering wire. If some solder is
left at the joint on the board, the new IC will not be attached properly.
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