Panasonic KX-NS0180X Service Manual ▷ View online
17
KX-NS0180X
4.2.3.5.
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.
4.2.3.6.
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-NS0180X
4.2.3.7.
Surge Protection
Thyristor is installed between T or R and FG protect from extraneous surge.
4.2.3.8.
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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KX-NS0180X
4.2.3.9.
EXT-CID Transmission
This CODEC(IC602) generates the extension Caller ID signals (FSK signal) with the CPU control.
The data flow is shown below.
The data flow is shown below.
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KX-NS0180X
4.2.4.
Power Supply Voltage Generator
• Block Diagram
The input from the main power supply is in 1 voltage levels: +15V.
Since the voltage levels: +15V,+5V,+3.3V,+2.5V,+80V,-55V are required onboard, voltage levels are generated onboard as writ-
ten below.
Since the voltage levels: +15V,+5V,+3.3V,+2.5V,+80V,-55V are required onboard, voltage levels are generated onboard as writ-
ten below.
• Protection of 5V/3.3V output
The protection circuit consists of an output short protection and an overvoltage protection.
When an output of power supply is short, IC802 or IC803 works to stop the output as the output short protection.
When +5V and/or +3V output become overvoltage caused by Q802 and/or Q803 short, it is detected by D806 and D807.
When an output of power supply is short, IC802 or IC803 works to stop the output as the output short protection.
When +5V and/or +3V output become overvoltage caused by Q802 and/or Q803 short, it is detected by D806 and D807.
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