Panasonic KX-TG2248S Service Manual ▷ View online
Call Waiting Caller ID
Calling Identity Delivery on Call Waiting (CIDCW) is a CLASS service that allows a customer, while off-hook on an existing call, to
receive information about a calling party on a waited call. The transmission of the calling information takes place almost
immediately after the customer is alerted to the new call so he/she can use this information to decide whether to take the new call.
receive information about a calling party on a waited call. The transmission of the calling information takes place almost
immediately after the customer is alerted to the new call so he/she can use this information to decide whether to take the new call.
Function:
The telephone exchange transmits or receives CAS and ACK signals through each voice RX/TX route. Then FSK data and MARK
data pass the following route.
data pass the following route.
Telephone Line
→
CN1(A, B)
→
C11, C12
→
R14, R15
→
DSP (39~40).
. If the unit deems that a telephone connected in parallel is in use, ACK is not returned even if CAS is received, and the information
for the second and subsequent callers are not displayed on the portable handset display.
for the second and subsequent callers are not displayed on the portable handset display.
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KX-TG2248S
18 BLOCK DIAGRAM (Handset)
D206~D209
Q207
XIN
VRF
BMCCLK
RF BLOCK
VCC
VCCA
PDN
RSTN
CHG
SPOUTP, SPOUTN
MIP, MIN
LOUT0
LOUT0
LIN0
HSSPOUT
EEPROM_DI
XOUT
RESET
Q205
CHARGE
CHARGE
DET
HSMIP
HEAD SET
JACK
JACK
RINGER
MIC
SPEAKER
TO LCD UNIT
(CALLER ID)
IC202
EEPROM
EEPROM
KEY
PAD
PAD
KEY
LEDS
8.192MHz
X201
OSC
CN203
LCD_
∗
EEPROM_DO
VCCPA
VCCPLL
VCCPLL
2
1
BATT
BATT1
BATT2
D214
D216
IC201
DSP
TXEN
SHCTRL
TXO (VMOD)
RSTH
RSSI
PCTRL
RXEN
RXI (RXDATA)
RX GAIN
SIO_DO
SIO_LE
SIO_CLK
OSC
BUFFER AMP
BUFFER AMP
Q204
KX-TG2248S BLOCK DIAGRAM (HANDSET)
64
65
57
62
100
63
58
23
24
25
59
16~22 27
60
36
23
44
34
29
74
54
55
IC1
50
32
41
14
51
52
46 47
66
48
POWER
DOWN
DOWN
IC205
IC203
3.0V
REG
IC204
3.0V
REG
DC-DC
CONVERTER
CONVERTER
Q212, L210
P217, C318
P217, C318
2.6V
REG
REG
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KX-TG2248S
19 CIRCUIT OPERATION (Handset)
19.1. Construction
The circuit mainly consists of DSP and RF unit as shown in the block diagram.
19.1.1. DSP:IC201
Function
•
•
Battery Low, Power down detect circuit
•
•
Ringer Generation
•
•
Interface circuit
RF unit, speaker, mic, LED, Key scan, LCD, Headset
19.1.2. RF unit
Mainly voice signal is modulated to RF, or it goes the other way.
19.1.3. EEPROM: IC202
All setting data is stored.
ex: ID code, user setting (Flash Time, Tone/Pulse)
19.2. Power Supply Circuit
Voltage is supplied separately to each block.
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KX-TG2248S
19.3. Charge Circuit
Ni-Cd battery is connected to (BATT+, BATT-). When the handset is put on the cradle of the base unit, the power is supplied from
CHARGE1 and CHARGE2 terminals to charge the battery. Q207 detects the voltage of CHARGE1 and CHARGE2 terminals, then
the handset makes ID code setting (*) with the base unit.
CHARGE1 and CHARGE2 terminals to charge the battery. Q207 detects the voltage of CHARGE1 and CHARGE2 terminals, then
the handset makes ID code setting (*) with the base unit.
19.4. Ringer and Handset SP-Phone
DSP (29-31)
→
SP/RINGER
19.5. Sending Signal
The voice signal from the microphone input to DSP (46-47). CN203 is the headphone jack. When the headphone is connected, the
Q206 detect it. The input from the microphone of the handset (MIN, MIP) is cut and the microphone signal from the headphone is
input to DSP (36). Also the power for the microphone is supplied from Q211, and the power is turned OFF on standby.
Q206 detect it. The input from the microphone of the handset (MIN, MIP) is cut and the microphone signal from the headphone is
input to DSP (36). Also the power for the microphone is supplied from Q211, and the power is turned OFF on standby.
Note: DSP is IC201.
See CPU DATA (Handset) (P.68).
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KX-TG2248S
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