Panasonic KX-NS0290CE Service Manual ▷ View online
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KX-NS0290CE
4.3.
Circuit Operation (SLC2Block)
4.3.1.
Description of Functions and Circuits (SLC)
4.3.1.1.
CODEC Function (IC602)
Infineon(Lantiq) PEB3265 CODEC is installed. The analogue features such as BN, frequency characteristic, volume level, sidetone
are configured by FPGA CODEC interface DCLK, CS, DOUT, DIN. Also, it converts A/D to D/A, and 4-line-analogue signal to PCM
code in G.711 format.
are configured by FPGA CODEC interface DCLK, CS, DOUT, DIN. Also, it converts A/D to D/A, and 4-line-analogue signal to PCM
code in G.711 format.
4.3.1.2.
2W-4W Conversion
It converts 4W-VOX signal used in the PBX to 2W-VOX signal used in SLT, and vice versa. It consists of an operational amplifier in
the SLIC and a balanced network (B/N) in the CODEC. It can control the return loss of the audio data and frequency characteristics.
By modifying the CODEC program, it can match the corresponding impedance.
the SLIC and a balanced network (B/N) in the CODEC. It can control the return loss of the audio data and frequency characteristics.
By modifying the CODEC program, it can match the corresponding impedance.
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KX-NS0290CE
4.3.1.3.
DTMF Signal Detection
Each port has its own DTMF receiver in the codec.
Detection of DTMF signal by Codec transmits this data to the MPR via the NS_MAIN.
Via the FPGA, MPR reads the DTMF signal which is received in the Codec.
Detection of DTMF signal by Codec transmits this data to the MPR via the NS_MAIN.
Via the FPGA, MPR reads the DTMF signal which is received in the Codec.
4.3.1.4.
Power Supply
Voltage and current generated by the SLIC is supplied to the phones.
Preset voltage is -52V.
Current is set as 26mA.
Preset voltage is -52V.
Current is set as 26mA.
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KX-NS0290CE
4.3.1.5.
Hook Detection
The off-hook status is detected when the telephone is off-hook. When a telephone is off-hook, change in current is detected in SLIC,
and this information is transmitted to the ITA/B pin of SLIC (27, 36pin) as OFF-HOOK=L/ON HOOK=H signal. This digital signal is
received by CODEC IC and recognized as off-hook signal. The off-hook status is analyzed by software.
and this information is transmitted to the ITA/B pin of SLIC (27, 36pin) as OFF-HOOK=L/ON HOOK=H signal. This digital signal is
received by CODEC IC and recognized as off-hook signal. The off-hook status is analyzed by software.
4.3.1.6.
Ring Trip feature
During ringing, the ring current is permanently sensed by the IC601. Signal of the ring current is supplied to the
CODEC IC602 by means of the ITA/B signal.This current signal is continuously sampled by the CODEC.
When the handset of a ringing telephone is picked up, the current is compared against the programmed ring trip threshold. If it is
above the programmed ring trip threshold, the ringing signal is automatically removed from the Tip-Ring interface during zero cross-
ing.
CODEC IC602 by means of the ITA/B signal.This current signal is continuously sampled by the CODEC.
When the handset of a ringing telephone is picked up, the current is compared against the programmed ring trip threshold. If it is
above the programmed ring trip threshold, the ringing signal is automatically removed from the Tip-Ring interface during zero cross-
ing.
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KX-NS0290CE
4.3.1.7.
Surge Protection
Thyristor is installed between T or R and FG protect from extraneous surge.
4.3.1.8.
Bell Signal Generator and Transmission
In ringing mode, the ringing DC offset and the ringing signal are summed digitally within CODEC in accordance with the pro-
grammed values.
This signal is then converted to an analog signal and applies to the SLIC.
The SLIC amplifies the signal and supplies the line with 65 Vrms.
The bell signal is generated with +80V(VHR) and -55V (VBAT) supplied to SLIC.
grammed values.
This signal is then converted to an analog signal and applies to the SLIC.
The SLIC amplifies the signal and supplies the line with 65 Vrms.
The bell signal is generated with +80V(VHR) and -55V (VBAT) supplied to SLIC.
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