Panasonic KX-TEA308NE, KX-TE82460NE, KX-TE82492NE, KX-TE82493NE, KX-A227X Service Manual

ORDER NO. KMS0507104CE

Advanced Hybrid System

KX-TEA308NE

KX-TE82460NE KX-TE82492NE KX-TE82493NE KX-A227X

(for Europe)

IMPORTANT INFORMATION ABOUT LEAD FREE, (PbF), SOLDERING

If lead free solder was used in the manufacture of this product the printed circuit boards will be marked PbF.

Standard leaded, (Pb), solder can be used as usual on boards without the PbF mark.

When this mark does appear, please read and follow the special instructions described in this manual on the use of PbF and how it might be permissible to use Pb solder during service and repair work.

KX-TEA308NE

CONTENTS

Page Page

1 ABOUT LEAD FREE SOLDER (PbF: Pb free) 4

1.1. SUGGESTED PbF SOLDER

1.2. HOW TO RECOGNIZE THAT Pb FREE SOLDER IS

USED

2 FOR SERVICE TECHNICIANS

3 CAUTION

3.1. SAFETY PRECAUTIONS

3.2. INSULATION RESISTANCE TEST

3.3. BATTERY CAUTION

3.4. CAUTION

4 SPECIFICATIONS

4.1. GENERAL DESCRIPTION

4.2. CHARACTERISTICS

4.3. SYSTEM CAPACITY

5 SYSTEM OVERVIEW

5.1. SYSTEM COMPONENTS

5.2. SYSTEM CONNECTION DIAGRAM

6 NAMES AND LOCATIONS

7 CONNECTION

7.1. SERIAL INTERFACE CONNECTION

8 DISASSEMBLY INSTRUCTIONS

8.1. DISASSEMBLY INSTRUCTION

9 BLOCK DIAGRAM

9.1. SYSTEM BLOCK DIAGRAM

9.2. POWER BLOCK DIAGRAM

9.3. KX-TEA308NE MAIN BLOCK DIAGRAM

9.4. KX-TEA308NE CO BLOCK DIAGRAM

9.5. KX-TEA308NE POWER SUPPLY UNIT BLOCK

DIAGRAM

10 EXPLANATION OF BLOCK DIAGRAM

10.1. MAIN UNIT (KX-TEA308NE)

11 CIRCUIT OPERATION

11.1. POWER SUPPY CIRCUIT

11.2. CO INTERFACE CIRCUIT

11.3. CROSS POINT SWITCH CIRCUIT

11.4. INTERCOM CIRCUIT

11.5. POWER FAILURE THROUGH CALL SWITCHING

CIRCUIT

11.6. DATA COMMUNICATION CIRCUIT

11.7. CONTROL CIRCUIT

11.8. TONE GENERATOR CIRCUIT

11.9. DTMF GENERATOR CIRCUIT

11.10. DTMF RECEIVER CIRCUIT

11.11. INT CALLID INTERFACE CIRCUIT

11.12. MODEM INTERFACE CIRCUIT

11.13. USB INTERFACE CIRCUIT

11.14. OGM INTERFACE CIRCUIT

11.15. RINGING SIGNAL GENERATO R CIRCUIT

11.16. SMDR INTERFACE CIRCUIT

11.17. DOORPHONE CARD INTERFACE (KX-TE8246 0NE)

11.18. BUILT IN VOICE MESSAGE CARD INTERFACE (KX-

TE82492NE)

11.19. CALL ID CARD INTERFACE (KX-TE82493NE)

12 TROUBLESHOOTING GUIDE

12.1. NO OPERATION (Check POWER SUPPLY BOARD,

MAIN BOARD and 2AP BOARD)

12.2. NO DIAL TONE

12.3. CANNOT DIAL

12.4. CANNOT CALL EXTENSION

12.5. CANNOT USE PROPRIETA RY TELEPHONE

12.6. CANNOT RECEIVE INCOMING CALL

12.7. CANNOT SEND DTMF DIALING

12.8. CANNOT RECEIVE CALL DIAL TONE

12.9. CANNOT SEND A HOLD ON MUSIC

13 IC DATA

13.1. IC700

13.2. IC7

13.3. IC8

14 TERMINAL GUIDE OF ICS, TRANSISTORS AND DIODES

15 HOW TO REPLACE A FLAT PACKAGE IC

15.1. PREPARATION

15.2. REMOVAL PROCEDURE

15.3. INSTALLATION PROCEDURE

15.4. REMOVING SOLDER FROM BETWEEN PINS

16 FIXTURES AND TOOLS

17 CABINET AND ELECTRICAL PARTS LOCATION

18 ACCESSORIES AND PACKING MATERIALS

19 REPLACEMENT PARTS LIST (KX-TEA308NE)

19.1. CABINET AND ELECTRICAL PARTS

19.2. ACCESSORIES AND PACKING MATERIALS

19.3. MAIN BOARD PARTS

19.4. CO BOARD PARTS

19.5. POWER SUPPLY BOARD PARTS

19.6. FIXTURES AND TOOLS

20 FOR THE SCHEMATIC DIAGRAM

21 SCHEMATIC DIAGRAM (KX-TEA308NE)

21.1. MAIN No.1 (Extention A-D Block)

21.2. MAIN No.2 (Extention E-H Block)

21.3. MAIN No.3 (Cross-Point Block)

21.4. MAIN No.4 (ASIC, Memory Block)

21.5. MAIN No.5 (CO Block)

21.6. POWER SUPPLY

22 PRINTED CIRCUIT BOARD (KX-TEA308NE)

22.1. MAIN BOARD

22.2. CO BOARD

22.3. POWER SUPPLY

23 KX-TE82460NE (2-PORT DOORPHONE CARD)

23.1. HOW TO RECOGNIZE THAT Pb FREE SOLDER IS

USED

23.2. LOCATION OF OPTIONAL CARDS

KX-TEA308NE

23.3. DOORPHONE/DOOROPENER CARD BLOCK DIAGRAM

23.4. EXPLANATION OF BLOCK DIAGRAM/CIRCUIT

OPERATIONS

23.5. TROUBLESHOOTING GUIDE

23.6. IC DATA

23.7. TERMINAL GUIDE OF ICS, TRANSISTORS AND

DIODES

23.8. ACCESSORIES AND PACKING MATERIALS

23.9. REPLACEMENT PARTS LIST (KX-TE82460NE)

23.10. FOR THE SCHEMATIC DIAGRAM

23.11. SCHEMATIC DIAGRAM (KX-TE8246 0NE)

23.12. PRINTED CIRCUIT BOARD (KX-TE8246 0NE)

24 KX-TE82492NE (2-CHANNEL VOICE MESSAGE CARD)

24.1. HOW TO RECOGNIZE THAT Pb FREE SOLDER IS

USED

24.2. LOCATION OF OPTIONAL CARDS

24.3. BLOCK DIAGRAM

24.4. CIRCUIT OPERATIONS

24.5. TROUBLESHOOTING GUIDE

24.6. IC DATA

24.7. TERMINAL GUIDE OF ICS, TRANSISTORS AND

DIODES

101

102

104

105

106

107

108

109

110

112

113

24.8. ACCESSORIES AND PACKING MATERIALS

24.9. REPLACEMENT PARTS LIST (KX-TE82492NE)

24.10. FOR THE SCHEMATIC DIAGRAM

24.11. SCHEMATIC DIAGRAM (KX-TE8249 2NE)

24.12. PRINTED CIRCUIT BOARD (KX-TE8249 2NE)

25 KX-TE82493NE (3-PORT CALLER ID CARD)

25.1. HOW TO RECOGNIZE THAT Pb FREE SOLDER IS

USED

25.2. LOCATION OF OPTIONAL CARDS

25.3. BLOCK DIAGRAM

25.4. CIRCUIT OPERATIONS

25.5. TROUBLESHOOTING GUIDE

25.6. IC DATA

25.7. TERMINAL GUIDE OF ICS, TRANSISTORS AND

DIODES

25.8. ACCESSORIES AND PACKING MATERIALS

25.9. REPLACEMENT PARTS LIST (KX-TE82493NE)

25.10. FOR THE SCHEMATIC DIAGRAM

25.11. SCHEMATIC DIAGRAM (KX-TE8249 3NE)

25.12. PRINTED CIRCUIT BOARD (KX-TE8249 3NE)

26 KX-A227X (BACK-UP BATTERY CABLE)

26.1. ACCESSORIES AND PACKING MATERIALS

26.2. REPLACEMENT PARTS LIST (KX-A227X)

113

114

115

116

118

119

120

121

122

123

124

126

127

129

130

132

133

134

135

KX-TEA308NE

1 ABOUT LEAD FREE SOLDER (PbF: Pb free)

Note:

In the informa tion below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that contains lead.

We will use PbF solder when discussing the lead free solder used in our manufa cturing process which is made from Tin, (Sn), Silver, (Ag), and Copper, (Cu).

This model, and others like it, manufa ctured using lead free solder will have PbF stamped on the PCB. For service and repair work we suggest using the same type of solder although, with some precautions, standard Pb solder can also be used.

Caution

•

• PbF solder has a melting point that is 50° ~ 70° F, (30° ~ 40°C) higher than Pb solder. Please use a soldering iron with

• •

temperature control and adjust it to 700° ± 20° F, (370° ± 10°C). In case of using high temperature soldering iron, please be careful not to heat too long.

•

• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100°F, (600°C).

• •

•

• If you must use Pb solder on a PCB manufactured using PbF solder, remove as much of the original PbF solder as possible

• •

and be sure that any remaining is melted prior to applying the Pb solder.

•

• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the

• •

opposite side (See figure, below).

1.1. SUGGESTED PbF SOLDER

There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper,

(Sn+Ag+Cu), you can also use Tin and Copper, (Sn+Cu), or Tin, Zinc, and Bismuth, (Sn+Zn+Bi). Please check the manufacturer’s specific instructions for the melting points of their products and any precautions for using their product with other

materials.

The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3mm, 0.6mm and 1.0mm.

1.2. HOW TO RECOGNIZE THAT Pb FREE SOLDER IS USED

KX-TEA308NE

2 FOR SERVICE TECHNICIANS

ICs and LSIs are vulnerable to static electricity.

When repairing, the following precautions will help prevent recurring malfunctions.

1. Cover the plastic parts boxes with aluminum foil.

2. Ground the soldering irons.

3. Use a conductive mat on the worktable.

4. Do not touch IC or LSI pins with bare fingers.

KX-TEA308NE

3 CAUTION

3.1. SAFETY PRECAUTIONS

1. Before servicing, unplug the power cord to prevent an electric shock.

2. When replacing parts, use only the manufacturer´s recommended components for safety.

3. Check the condition of the power cord. Replace if wear or damage is evident.

4. After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields, etc.

5. Before returning the serviced equipment to the customer, be sure to perform the following insulation resistance test to prevent the customer from being exposed to shock hazards.

3.2. INSULATION RESISTANCE TEST

1. Unplug the power cord and short the two prongs of the plug with a jumper wire.

2. Turn on the power switch.

3. Measure the resistance value with ohmmeter between the jumpers AC plug and each exposed metal cabinet part, such as screw threads, control shafts, handle brackets, etc.

Note:

Some exposed parts may be isolated from the chassis by design. These will read infinity.

4. If the measurement is outside the specified limits, there is a possibility of shock hazard. The equipment should be repaired and rechecked before it is returned to the customer.

3.3. BATTERY CAUTION

1. Danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Dispose of used batteries according to the manufacturer’s Instructions.

2. The lithium battery is a critical component (type No.CR23541). Please observe for the proper polarity and the exact location when replacing it and soldering the replacement lithium battery in.

3.4. CAUTION

The power socket wall outlet should be located near this equipment and be easily accessible.

4 SPECIFICATIONS

4.1. GENERAL DESCRIPTION

Control Bus Original bus (16-bit, 24 MHz) Switching Space Division CMOS Crosspoint Switch Power Input 100 V AC to 240 V AC, 0.8A to 0.4A, 50 Hz/60Hz External Battery +24 V DC (+12 V DC x 2) Maximum Power Failure Tolerance 300 ms (without using backup batteries) Memory Backup Duration 7 years Dialling Outside (CO) Line Pulse (10 pps, 20 pps) or Tone (DTMF)

Extension Pulse (10 pps, 20 pps) or Tone (DTMF) Intercom Path 3 Mode Conversion Pulse-DTMF Ring Frequency 20 Hz/25 Hz (selectable) Operating Environment Temperature 0°Cto40°C

Humidity 10 % to 90 % (non-condensing) Conference Call Outside (CO) Line 2 Music on Hold (MOH) 1 port

Selectable MOH: Internal/Exte rnal/Tone

Paging Internal 1

Extension 1 port Serial Interface Port RS-232C 1

USB 1.1 1 Extension Connection Cable SLT 1 pair wire (T, R)

PT 2-pair wire (T, R, H, L)

DSS Console 1-pair wire (H, L) Dimension 249 mm (W) x 316 mm (H) x 73 mm (D) Weight (when fully expanded) Approx. 1.8 kg

KX-TEA308NE

4.2. CHARACTERISTICS

Terminal Equipment Loop Limit PT 40 Ω

SLT 600 Ω including set

Doorphone 20 Ω Minimum Leakage Resistance 15000 Ω minimum Maximum Number of Extension

Instruments per Line Ring Voltage 65 Vrms at 20 Hz/25 Hz depending on the ringing load Outside (CO) Line Loop Limit 1600 Ω maximum Hookswitch Flash/Recall Timing Range 24 ms-2032 ms Door Opener Current Limit 30 V DC/30 V AC, 3 A maximum Paging Terminal Impedance 600 Ω MOH Terminal Impedance 10000 Ω

1 PT or SLT in standard connection

1 PT and 1 SLT in parallel connection

4.3. SYSTEM CAPACITY

4.3.1. System Capacity

Basic System Outside (CO) line 3

Extensions for PT/SLT 8

KX-TEA308

KX-TEA308NE

4.3.2. Maximum Cards Terminal Equipment

ltem KX-TEA308 PT 8 SLT 8 2-Port Doorphone Card 1 3-Port Caller ID Card 1 2-Channel Voice Message Card 1 Doorphone 2 Door Opener 2 Pager 1 Music on Hold (MOH) 1 DSS Console 2

4.3.3. System Data

ltem Max. Quantity Operator 1 System Speed Dialling 100 One-touch Dialling 24 per extension (PT) Personal Speed Dialling 10 per extension Call Park Area 10 Absent Message 6 Toll Restriction (TRS) COS 5 Extension Group 8 Message Waiting 8 per extension Message for Built-in Voice Message 125 messages (total 60 minutes)

5 SYSTEM OVERVIEW

5.1. SYSTEM COMPONENTS

Model Description Main Unit KX-TEA308NE Advances Hybrid System: 3 Outside (CO) Line, 8 Hybrid Extentions Optional Service Cards KX-TE82460NE

KX-TE82492NE KX-TE82493NE

Proprietary Equipment KX-T30865

KX-A227X

2-Port Doorphone Card 2-Channel Voice Message Card 3-Port Caller ID Card

Doorphone Backup Battery Cable

5.2. SYSTEM CONNECTION DIAGRAM

KX-TEA308NE

•

• Connect a display-equipped proprietary telephone (PT) to extension jack 01, as this extension is automatically designated as

• •

the manager extension.

KX-TEA308NE

6 NAMES AND LOCATIONS

7 CONNECTION

7.1. SERIAL INTERFACE CONNECTION

8 DISASSEMBLY INSTRUCTIONS

8.1. DISASSEMBLY INSTRUCTION

1. Pull the slide button (arrow 1) to the right and, holding it, slide the cable cover upwards (arrow 2).

2. Then turn the cable cover slightly to remove it.

KX-TEA308NE

3. Remove the three screws (A).

4. Holding the protrusions on both sides of the front cover, swing the cover open.

5. Holding the front cover open at about a 45° angle, remove the front cover by pushing it in the direction of the arrow as shown on the right.

KX-TEA308NE

5. Remove the 1 screws (A).

6. Remove the power supply board cover.

7. Pull out the 4 connectors.

8. Remove the 2 screw (B) and 1 screw (A).

9. Remove the power supply board.

10. Remove the 2 screw (B).

11. Remove the CO board.

12. Pull out the 1 connector.

13. Remove the 2 screws (A) and 1 screw (B).

14. Remove the main board.

Procedure:

•

• Insert the SW CABLE into AC POWER SWICH.

• •

Caution:

•

• Be sure each colored wire is inserted to the correct lug (very important).

• •

9 BLOCK DIAGRAM

9.1. SYSTEM BLOCK DIAGRAM

KX-TEA308NE

9.2. POWER BLOCK DIAGRAM

9.3. KX-TEA308NE MAIN BLOCK DIAGRAM

CN708

Door Phone

Door Opener

CONNECTOR

CN707

BV Card

CONNECTOR

CN701

(2AP)

CONNECTOR

CN706

CO CID

CONNECTOR

CN703

D-Sub

CN704

CN710

POWER UNIT CONNECTOR

Card

USB

DOOR1,2

TAM1-2,TONE

CO1-3

BGM

PAG E

I/O,DTMFG

Host i/f

(UART)RXD,TXD

TONE

25Hz

CROSS

POINT

IC601 IC602 IC603

ROM

SRAM

ASIC

IC700

8086

DSP

P I O

APT i/f

PIO

ASIC

Ringer Circuit

EXT1-8

IC606, IC607

DTMFR(1,2)

(For EXT)

620,440,350Hz

IC705 IC704

OGM,Modem

Q1-4,TOE1,2,STD1,2

(APT i/f)PRX,PTX,PTXE1-3

(I/O)HOOK1-8,BELL1-8

TONE

Int CID(FSK,DTMF)

IC7, IC8

BELL

EXT1

EXT2

EXT3

EXT4

EXT5

EXT6

EXT7

EXT8

KX-TEA308NE 1AP BLOCK DIAGRAM

9.4. KX-TEA308NE CO BLOCK DIAGRAM

KX-TEA308NE

9.5. KX-TEA308NE POWER SUPPLY UNIT BLOCK DIAGRAM

Primary Secondary

D10 ~ D13

Rectifier

Smoother

IC1

Control Circuit

R30, R31

Over Current Detection

D101, C101

PC1

Rectifier

Smoother

Voltage Detection

IC101

DC-DC

Converter

AC IN

CN1

FUSE

Surge Protector

Noise Filter

RL501

Q503

Battery Back-up Adaptor

IC201

IC301

DC-DC

+24

GND

+27V

GND

+15V

+3.3V

KX-TEA308NE POWER SUPPLY UNIT BLOCK DIAGRAM

KX-TEA308NE

10 EXPLANATION OF BLOCK DIAGRAM

10.1. MAIN UNIT (KX-TEA308NE)

10.1.1. Power Supply Circuit

This power supply unit is a switching power supply. Power supply unit supplies DC voltage (+27V,+15V,3.3V) to main board and other optional cards. And this unit has an adaptor circuit to back up battery.

10.1.2. COL Interface Circuit

There are the interface circuits linking the CO line (CO1 -CO3) and the cross point circuit section.

10.1.3. Cross Point Circuit

This is a space division switching system for connecting the following:

The eight extension circuits with the three CO, DTMF generator, DTMF receiver, INT-CALL ID, MODEM, OGM, BV, paging, music on hold, tone etc.

It is composed of 3 C-MOS IC´s. (8 X 16 matrix: 1pcs and 4 X 8 matrix: 2pce).

10.1.4. Intercom Circuit

This is the interface circuit of the single line telephone, and it is composed of 8 intercom circuit (ICM1-8).

10.1.5. Power Failure Through Call Switching Circuit

There is one power failure transfer circuit (CO1-EXT101).

10.1.6. Data Communication Circuit

The APT i/f module which performs communication with a private telephone machine is built in ASIC.

10.1.7. Control Circuit

A control block consists of CPU (compatibility with Intel 8086) (IC700), Flash ROM (8Mbit) (IC705) and SRAM (4Mbit) (IC704).

RTC, Timer, DMAC, USB Controller, WDT, INTC, UART, General Purpose I/O ports, APT i/f and DSP are built into CPU chip.

General purpose I/O block is composed by discrete parts (IC7, IC8) and the I/P port in CPU.

IC7 and IC8 control extension, and the I/O ports in CPU control the COL chiefly.

In order to maintain time, system data and others, RTC (Real Time Clock) in CPU and SRAM are backed up with the lithium battery.

10.1.8. Tone Generator Circuit

The rectangle wave generated by the timer of CPU is changed into sine wave with a low pass filter, and various tones are generated.

10.1.9. DTMF Generator Circuit

DTMF (Dial Tone Multi Frequency) generator is used for dispatch to outside line, and communication with the voice mail connected to the extension.

10.1.10. DTMF Receiver Circuit

The circuit that receives the Dial Tone Multi Frequency by which extension dispatch is carried out with the DTMF receiver connected to the crossing point.

10.1.11. Int Call ID Circuit

FSK/DTMF generated by DSP in CPU are connected even to a crossing point through AMP. The circuit which sends out a CALLID signal to the telephone connected to an extension by connecting the line of INT-CALL-ID with arbitrary extensions.

10.1.12. Modem Circuit

The MODEM signal generated by DSP in CPU is connected even to a crossing point through AMP.

The circuit, which connects the line of MODEM with arbitrary outside line, and enables MODEM communication with outside line.

10.1.13. USB Circuit

The circuit which makes communication possible by PC and 1.1 standards by the USB controller in CPU.

KX-TEA308NE

10.1.14. OGM Circuit

The 4M Serial Flash ROM is connected to CPU by the memory controller in DSP (in CPU).

A maximum of 3-minute storing of OGM is possible to a serial flash ROM.

10.1.15. Ring Signal Generator Circuit

This section generates the ring signal for the single line telephone. A 20/25Hz square wave is generated by the CPU timer and sent to low pass filter and the Ring signal is amplified by BELL amplifier circuit, and then passed it through the ringing signal switching relay to the single line telephone.

10.1.16. SMDR Interface Circuit

This is the RS232C interface port. When the port is connected to a printer. The port can be used to output the SMDR feature recording messages and the contents of the system program.

10.1.17. Door Phone Interface

An doorphone card interface consists of two intercom paths connected to a crossing point, and address data and CS signals.

10.1.18. Call ID Interface

A CALLID card interface consists of three CALLID signal lines from outside line, and address data and CS signal.

10.1.19. BV Interface

BV card interface consists of two BV telephone call paths connected to a crossing point, and address data and CS signals.

KX-TEA308NE

11 CIRCUIT OPERATION

11.1. POWER SUPPY CIRCUIT

11.1.1. The function of the power unit are listed below

AC-DC Inverter Function This function isolates and converts the AC input voltage to DC

DC-DC Converter Function This function outputs DC+15V and 3.3V from the inputted

Battery Back Up Adaptor Function This function connects battery and service unit without battery

input and output of DC27V.

DC27V.

adaptor, only needs a cable connected to the battery and service unit.

KX-TEA308NE

11.1.2. Control Section

1) AC-DC Inverter Function

The AC input voltage is rectified and smoothed by D10-13 and C5. The obtained DC voltage is converted into a rectangular wave by the switching transistor Q1, then isolated and transduced by T1. This converted rectangular wave is rectified and smooth ed by D101 and C101 to output DC27V. The DC27V is transmitted to the primary side by PC1 and then PWM- controlled to keep constant. The switching frequency of Q1 is approximately 60KHz.

2) DC-DC Inverter Function

The DC 27V DC is converted into a rectangular wave by control IC201, and then output as an output voltage of +15V by the smoothing circuit which is composed of D201, L201, C201.

The 27V DC is converted into rectangular wave by control IC301 and then output as an output voltage of +3.3V by the smoothing circuit which is composed of D301, L301, C301.

3) Battery back up function

This back up battery adaptor circuit has DC supply function, from battery (+24V) to service unit and DC charge from service unit to battery (+24V). Charge current is typ. 0.3A.

11.2. CO INTERFACE CIRCUIT

11.2.1. Composition

This is composed of the following circuit:

1) Bell signal detection

2) DC loop formation circuit

3) Pulse dial transmission circuit

4) CALL ID interface circuit

5) COL bidirectional amplifie r circuit

1) Bell signal detection

When CO line is idle, photo coupler PC1, PC2 are OFF.

When there is an incoming signal from CO line, the current flows PC1 as in the following way.

Tip → L1 → R2 → PC1(1-2) → C3 → R5 → L1 → Ring: This cause pin4 of PC1 to change the level from High to low.

Ring → L1 → R5 → C3 → PC2(1-2) → R2 → L1 → Tip: This cause pin4 of PC2 to change the level from High to low.

KX-TEA308NE

2) DC loop formation circuit

In the off hook status, PC5 is ON.

DC loop path:

Tip→L1→D1→D2→D3→Q10(E-C)→Q1(C-E)→R9→R8→D3→L1→Ring

At this time, the output of the photo coupler PC1 changes level from High to low.

Ring→L1→D3→Q10(E-C)→Q1(C-E)→R9→R8→D3→D2→D1→L1→Tip

At this time, the output of the photo coupler PC2 changes level from High to low.

Afterwards, CPU monitor this change (low level to high level). If the high level continues for a specified time set by system data programming. CPU assumes that CO line has become On hook status. And the CO line circuits is restored to the idle status.

3) Pulse dial transmission circuit

When the Off hook status, pulse dial transmission is executed by alternating On hook and Off hook. The status of On hook or Off hook is controlled by the switching transistor Q10.

4) CALL ID interface circuit

It is insulated by the capacitors in a COL circuit, and the call ID signal inputted from outside line is transmitted to a CALLID option card.

The flow of a CALLID signal

Tip→L1→C29→R54→IC4

Ring→L1→C29→R55→IC4

KX-TEA308NE

5) COL Bidirectional Amplifier circuit

This circuit consists of bidirectional amplifier function for communication between the extensions and COL, returns loss compensation for conference, shunt function and mute function.

(Composition)

For transmitting signals from the extensions to COL, this circuit consists of R34, R35, R26, R27, R18, R29, C14, C15, C10, C16 and the operational amplifie r (IC1).

For transmitting signals from the COL to extensions, this circuit consists of R24, R25, R31, R28, R37, R30, C12, C13, C17, C18, and the operational amplifie r (IC1).

COL side-tone suppression circuit which includes a balanced network BN1 consists of R22 R23, C11 and R16, R17, R20, R21.

EXT side-tone suppression circuit which includes a balanced network BN2 consists of R41, R42 and R40, R43, R38, R39.

Also extension side-tone suppression circuit which includes a balanced network BN3 consists of R45, R46 for supplementing side-tone suppression during the conference commu nication.

The analog switch (IC2) is used for the following:

(1) Conference (Pin 6, 8 and 9)

(2) Shunt (Pin 12, 10 and 11)

(3) Mute (Pin 13, 1 and 2)

1) Conference switch

Normally, pin 6 of the analog switch IC2 is low level, but during conferences, this pin becomes high level. Because, during conferences, it should compensate the return loss by connecting the balance network BN2 and the balance network BN3 in parallel.

2) Mute switch

The mute switch consists of pin 13, 1 and 2 of the analog switch(IC2). This switch has the following functions.

a) When a dial signal (DP) is sent to the COL, signals from the extensions are blocked.

b) When the hold on music is sent to the COL, signals from the extensions are blocked.

c) When the COL interface circuit is in the idle state, oscillation of COL bidirectional amplifier is inhibited. When pin 13 of IC2 changes to low level, the interval between pins 1 and 2 of the analog switch turns off, and signals are blocked.

3) Shunt switch

The shunt switch consists of pin 12, 10 and 11 of analog switch IC2.It is used to prevent the pulse dialing signal which is transmitted to the extensions. When pin 12 of IC2 changes to high from low, the analog switch becomes ON (the interval between pin 10 and 11), and GAIN of the COL cross point operational amplifie r becomes zero.

Shunt SW Mute SW Conference SW pin no. of analog switch 12 13 6 No connection (idle) H (on) L (off) L (off) Two party call L (off) H (on) L (off) Conference L (off) H (on) H (on) Hold on music transmission H (on) H (on) L (off)

Condition of COL interface amplifier circuit and analog switches.

KX-TEA308NE

11.3. CROSS POINT SWITCH CIRCUIT

11.3.1. Composition

The cross point circuit composed of three cross point switch IC´s (IC601:8X16, IC602 and IC603:4X8).

1) Cross Point Switch IC Operation

The cross point SW (IC601) contains a 8X16 array of cross point switches along with a 7 to 128 line decoder and latch circuits. Any one of the 128 switches can be addressed by selecting appropriate seven address bits. The selected switch can be turned on or off by applying either logical one or zero to the DATA input. Chip select allows the cross point array to be cascaded for matrix expansion.

The cross point SW´s (IC602, IC603) contain 4X8 array of cross point switches along with a 5 to 32 line decoder and latch circuits. Any one of the 32 switches can be addressed by selecting appropriate five address bits. The selected switch can be turned on or off by applying either logical one or zero to the DATA input. Chip select allows the cross point array to be cascaded for matrix expansion.

KX-TEA308NE

11.4. INTERCOM CIRCUIT

11.4.1. INTERCOM CIRCUIT

1) Composition

This is composed of the following circuits:

a) +15V power source for the extension telephones

b) Hook detect for SLT and pulse dialing detect

c) Bell ring trip section

2) Circuit operation

a) Power supply to the telephone

With the telephone off hook, a DC loop is formed, and current is supplied to the telephone. This circuit is limited to about 30mA by Q200, Q202, R202, R204 and Q201, Q203, R203, R205.

+27V→R204→R202→Q200→RL201→telephone→RL201→Q201→R203→R205→AG

b) Hook detect for SLT and pulse dialing detect

When the telephone handset is taken off, DC loop is formed and the collector of U200 3,6 pin change to L from H.

And IC7 detects the off hook condition.

When the handset is replaced back on hook, the DC loop is interrupted and collector of U200 3,6 pin change to H from L and EXT Pulse dialing is input either in the on hook or off hook condition, and the break number (on hook condition) is counted and read as the dial number.

c) Bell ringing trip section

When the telephone is a signal line telephone, extension calling is executed by means of a ringing signal. When the ringing signal is supplied, RL201 turns ON and the current flows are as follows:

Bell generation circuit → ringing signal line → RL201 → telephone → R206 → AG → Bell generation circuit

KX-TEA308NE

11.5. POWER FAILURE THROUGH CALL SWITCHING CIRCUIT

11.5.1. Circuit operation

If an AC power failure lasts longer than one second (momentary power failure), the COL is directly connected to the extension.

The COL1 will be connected with EXT101.

11.6. DATA COMMUNICATION CIRCUIT

11.6.1. Composition

This circuit is composed of the ASIC and the data communication interface circuits for the ICM circuit.

11.6.2. Circuit Operation

1) Data Communication of CPU (IC700)

The APT i/f module is built into CPU.

An RX/TX couple signal is shared by eight APT communications; this communicates via the selection signal.

That is, in the APT i/f module, extension 1-8 port switch the port communicates every 4ms respectively with

#101→#102→#103→#104..... →#108→#101.....

When the extension is not connected with APT, it is recognized as an SLT connection and the dummy communication is established.

Interface block diagram of CPU and ICM

KX-TEA308NE

2) Data Communication of ASIC and PITS

When APT I/F Module in CPU send the request signal to the proprietary telephone and after receiving the key input information (19 pulses) from the proprietary telephone and sending data (47 pulses) for LED control. APT I/F Module will receive acknowledge signal from the proprietary telephone.

a) Reception

The data from the proprietary telephone is received via H and L lines along the path shown below.

H.L line → C208 → IC200 →T201 → R235 → Q210 → CPU

b) Transmission

The data to the proprietary telephone is transmitted along the following Path.

CPU → Q209 → Q215 → T201 → IC200 → C208 → H.L line

+ 105 hidden pages