Read Panasonic KX-NT136RU Service Manual online
8.5. CODEC(IC7) [ANALOG] CIRCUIT
TLV320AIC22 is used to IC7 for CODEC. IC7 communicates with the MAIN-CPU (IC1) by PCM interface.
This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in IC1.
The audio gain of each call is determined by download data from PBX.
When the voice can not be heard or is not being sent to the other side, it can be identified whether there is a problem on the
MAIN-CPU (IC1) side or the CODEC(IC7) side by watching the data of the PCM interface.
Which input among HANDSET, SPEAKERPHONE or HEADSET that will be sent to IC1 is determined by a switch built into the
CODEC.
Also, the echo canceller function is performed by DSP of IC1.
This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in IC1.
The audio gain of each call is determined by download data from PBX.
When the voice can not be heard or is not being sent to the other side, it can be identified whether there is a problem on the
MAIN-CPU (IC1) side or the CODEC(IC7) side by watching the data of the PCM interface.
Which input among HANDSET, SPEAKERPHONE or HEADSET that will be sent to IC1 is determined by a switch built into the
CODEC.
Also, the echo canceller function is performed by DSP of IC1.
1. Handset Call
Transmitting signal is inputted from handset microphone and amplified by IC9 and IC10
→ A/D conversion and PCM data
in IC7
→ Change PCM data to IP packet in IC1 → Ethernet IC (IC12) → Ethernet → then sent to PBX.
Receiving signal inputted from PBX is
→ Ethernet → Ethernet IC (IC12) → Change IP packet to PCM data in IC1 → D/A
conversion after the input to IC7 in PCM data
→ IC7 built-in Amp output→outputted from IC8 Amp to handset speaker.
2. Headset Call
Transmitting signal is inputted from headset microphone and amplified by IC9
→ A/D conversion and PCM data in IC7 →
Change PCM data to IP packet in IC1
→ Ethernet IC (IC12) → Ethernet → then sent to PBX.
Receiving signal inputted from PBX is
→ Ethernet → Ethernet IC (IC12) → Change IP packet to PCM data in IC1 → D/A
conversion after the input to IC7 in PCM data
→ IC7 built-in Amp output→outputted from IC8 Amp to headset speaker.
3. Speakerphone (SP-phone) Call
Transmitting signal is inputted from SP-phone microphone and amplified by IC10
→ A/D conversion and PCM data in IC7
→ Change PCM data to IP packet in IC1 → Ethernet IC (IC12) → Ethernet → then sent to PBX.
Receiving signal inputted from PBX is
→ Ethernet → Ethernet IC (IC12) → Change IP packet to PCM data in IC1 → D/A
conversion after the input to IC7 in PCM data
→ IC7 built-in Amp output→outputted from IC11 Amp to SP-phone speaker.
14
KX-NT136RU
Click on the first or last page to see other KX-NT136RU service manuals if exist.