Panasonic KX-TCA285RU Service Manual ▷ View online
9
KX-TCA285RU
• The charge current is controlled by IC203 of Handset.
Charge current characteristic is as follows.
Charging method is CCCV. (CC: constant current, CV: constant voltage)
Charging method is CCCV. (CC: constant current, CV: constant voltage)
• IC100-88pin (CHG_state)
• When handset is put on charger, handset detects battery charge.
• TH(IC203-6pin) is temperature detecting pin of battery.
The charge temperature range is 5 degree C to 40 degree C.
If charge temperature is above 40 degree C or below 5 degree C, charge stops.
If charge temperature is above 40 degree C or below 5 degree C, charge stops.
4.2.7.
Battery Low/Power Down Detector
"Battery Low" and "Power Down" are detected by BBIC (IC1) which checks the battery voltage.
The detected voltage is as follows;
The detected voltage is as follows;
• Battery Low
Battery voltage: V(Batt) 3.4V ± 50mV
The BBIC detects this level and "
“ starts flashing.
• Power Down
Battery voltage: V(Batt) 3.2V ± 50mV
The BBIC detects this level and power down.
The BBIC detects this level and power down.
IC100-88pin (CHG_state)
Charge controll
High
Charging
Low
Charge complete
Charge detect
IC1-24pin (CHG_DET)
Charge LED (Red LED)
ON
Above 1.5V
ON
OFF
Below 1.2V
OFF
Charge
Battery temperature
ON
0
C to 40 C
OFF
Below 5
C or above 40 C
CC charge
CV charge
Charge stop
CC charge
CV charge
Charge stop
I mA
I/10 mA
4.2 V
3.97 V
t
V, I
Battery voltage
Charge current
0 mA
0 V
Charge complete
Recharge
10
KX-TCA285RU
4.2.8.
LCD Circuit
• The LCD is controlled by SPI (LCD_SCL, LCD_RESET, LCD_CS, LCD_SID, LCD_CD).
• LCD back-light has 3 modes ( Brightness 1/2/3*) and back-light OFF.
• LCD back-light has 3 modes ( Brightness 1/2/3*) and back-light OFF.
*Brightness level: Brightness 1 > Brightness 2 > Brightness 3
Back-light Mode
IC401-4pin (CP_ON)
IC401-2pin (LCD_BL1)
IC401-3pin (LCD_BL2)
Brightness 1
High
High
High
Brightness 2
High
High
Low
Brightness 3
High
Low
Low
Back-light OFF
Low
Low
Low
11
KX-TCA285RU
4.2.9.
LED Circuit
• DPU(IC100) controls each LEDs.
4.2.10.
Vib Circuit
• Vibrator is controlled by IC1-23 pin.
Type of LED
LED ON
LED OFF
Bell LED (Green)
LED531
LED531
IC401-7pin = High
IC401-7pin = Low
Bell LED (RED)
LED530
LED530
IC401-5pin = High
IC401-5pin = Low
Key back-light LEDs (Yellow green)
LED520 - LED529
LED520 - LED529
IC401-3pin = High
(Q521 = ON)
(Q521 = ON)
IC401-3pin = Low
(Q521 = OFF)
(Q521 = OFF)
VIB ON
VIB OFF
IC1-23 pin (Q540)
High
(ON)
Low
(OFF)
12
KX-TCA285RU
4.2.11.
RF Circuit
Reception
A digital voice signal from LAN is received as "TX_DATA" (*1) by DMW in a cell station.
Then TX_DATA goes to RF part, and it's modulated to 1.9 GHz RF signal. The RF signal is amplified and fed to a selected
antenna by antenna diversity .
Then TX_DATA goes to RF part, and it's modulated to 1.9 GHz RF signal. The RF signal is amplified and fed to a selected
antenna by antenna diversity .
As for a portable station, RF signal of cell station is received in two antennas.
RFIC(IC1) of portable station compares RF signal levels from cell station and selects the antenna to be used.
RX signal in the selected antenna is amplified and down-converted to 864 kHz IF signal, then demodulated to digital data
"RX_DATA".
RFIC(IC1) converts RX_DATA into a voice signal and outputs it to speaker.
RFIC(IC1) of portable station compares RF signal levels from cell station and selects the antenna to be used.
RX signal in the selected antenna is amplified and down-converted to 864 kHz IF signal, then demodulated to digital data
"RX_DATA".
RFIC(IC1) converts RX_DATA into a voice signal and outputs it to speaker.
Transmission
A voice signal from microphone is encoded to digital data "TX_DATA" by RFIC(IC1) in a portable station.
TX_DATA goes to RF part, and it's modulated to 1.9 GHz RF signal. The RF signal is amplified and fed to a selected antenna by
antenna diversity.
TX_DATA goes to RF part, and it's modulated to 1.9 GHz RF signal. The RF signal is amplified and fed to a selected antenna by
antenna diversity.
As for a cell station, RF signal is received in two antennas.
RFIC of cell station compares RF signal levels from portable station and selects the antenna to be used.
RX signal in the selected antenna is amplified and down-converted to 864 kHz IF signal, then demodulated to digital data
"RX_DATA".
DMW is received RX_DATA (*1) as a voice signal from portable station and outputs it to LAN.
RFIC of cell station compares RF signal levels from portable station and selects the antenna to be used.
RX signal in the selected antenna is amplified and down-converted to 864 kHz IF signal, then demodulated to digital data
"RX_DATA".
DMW is received RX_DATA (*1) as a voice signal from portable station and outputs it to LAN.
Note:
(*1) TX_DATA and RX_DATA are bundled to one signal as "RXTXDATA" of DMW in cell station.
TX_RF
RX_RF
TX_RF
RX_RF
VBAT_3.0V
LNA_INN
ANT2
ANT1
RX_SW
TX_SW
BAL_OUT1
RSTN
BAL_OUT2
GND
LNA_INP
VCC_PA
C19
ATSTN
ATSTP
C1
C21
C3
IC1
38
TEST
39
RX_SW
40
LNA_INN
26
XIN
27
VDD_APU
28
VBAT_APU
29
VDD_IF
30
VCC_FE_IF
31
VCC_PA
32
BAL_OUT2
33
BAL_OUT1
41
LNA_INP
42
ATST_N
43
ATST_P/EXT_LNA
44
RSTN
45
VCC_VCO
46
ON_OFF
47
ON_OFF_OUT
48
IF_T_DATA
49
IF_MLSE
50
IF_RX1
51
IF_NPORST
IF_INT_ANA
IF_EN_DA
IF_EN_AD
IF_DATA_DA
IF_DATA_AD
IF_CLK_PLL
IF_CLK_IF
IF_CDC_DIR
IF_EN_DA
IF_EN_AD
IF_DATA_DA
IF_DATA_AD
IF_CLK_PLL
IF_CLK_IF
IF_CDC_DIR
36
GND_RF
37
ANT2
34
TX_SW
35
ANT1
IF_NARES
TO RF BLOCK
C49
GND
GND
GND
GND
GND
C48
ANT_TP1
1
2
GND
GND
GND
GND
LNA_INN
GND
GND
RX_SW
GND
GND
C44
LNA_INP
BAL_OUT1
ANT1
C50
ANT_TP2
1
2
ANT2
BAL_OUT2
GND
GND
GND
VCC_PA
C36
TX_SW
GND
C51
L40
GND
C39
C43
C31
L32
D51
D50
GND
GND
CL1
CL2
CL3
C52
GND
GND
L38
L42
L33
C47
C41
C53
L34
C34
C35
C37
C32
C30
C55
L30
L31
C42
L36
C45
C46
L35
L39
C33
GAP
GAP
Antenna diversity
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