Low-range Phone Dedicated Chip

7/28/2019 Low-range Phone Dedicated Chip

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TEA7088A

LOW-RANGE PHONE DEDICATED CHIP

January 1998

SO28

(Plastic Package)

ORDER CODE : TEA7088AFP

.RING- GENERATION OF 8 MELODY TONES

(Including the 3 German Melody Tones)- 4 STEPS DIGITAL CONTROL ON THE AM-

PLIFIER OUTPUT LEVEL.SPEECH- TRANSMIT GAINEXTERNALLY ADJUSTABLE- RECEIVINGGAINEXTERNALLYADJUSTABLE

- AGCSLOPEEXTERNALLYPROGRAMMABLE- SOFTCLIPPINGON SENDING CHANNEL- RECEIVE AMPLIFIER FOR PIEZO OR

ELECTRODYNAMIC TRANSDUCER- +6dB MODE ON RECEIVE CHANNEL- LINE POWER MANAGEMENT.DIALING- DTMF GENERATOR- LOW DC MASK DURING MAKE PERIOD

THROUGH MICROCONTROLLER SERIALBUS INTERFACE.MICROCONTROLLER INTERFACE

- 1.79MHz CLOCK OR 3.58MHz OSCILLATORINPUT

.MICROCONTROLLER POWER SUPPLY

.MICROCONTROLLER CONTROL INTER-FACE INCLUDING SERIAL BUS. LINE CURRENT EXTRACTOR FOR SUPPLYOF EXTERNAL PERIPHERALS

DESCRIPTION

The TEA7088A is a Telephone Analog Front Enddevice, TAFE, which integrates the three basicfunctions of a standard telephoneset :- Speech network,- DTMF generator,- Ringer generator on buzzer.

A complete telephone set can be designed usingTEA7088A associated with a low cost microcon-troller.

MIC2

DTMF

VREF

VRMC

DCL

DATA

RI

1

2

3

4

5

6

7

8

9

10

28

27

26

25

24

23

22

21

20

19

PON

RES

SOFT

RECIN

SN

GTR

MIC1

AGC

VCC

IVLS

GND

MSK

OS C

11

12

13

14

18

17

16

15

VS

VL

VMC

GREC

BUZ

EAR+

EAR-

VRING

7088A-01.EPS

PIN CONNECTIONS

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PIN DESCRIPTION

Name Pin N DescriptionSOFT 1 Transmit Softclipping Time Constant

RECIN 2 Receiving Input

SN 3 Sidetone Network Input

AGC 4 Line Current Regulation Stop Value

MIC1 5 Microphone Input

MIC2 6 Microphone Input

GTR 7 Transmit Gain Adjustment

VCC 8 Transmit and Receive Part Power Supply

GND 9 Ground

IVLS 10 Line Current Source Power Supply

VS 11 Voltage Stabil izer

VL 12 Positive Line

VMC 13 Unregulated Microcontroller Power Supply

GREC 14 Receive Gain Adjustment

EAR- 15 Negative Earphone Output

EAR+ 16 Positive Earphone Output

BUZ 17 Ringer Buzzer Output

VRING 18 Ring Power Supply

RES 19 Reset

PON 20 Power On

RI 21 Ring Indicator

OSC 22 Oscillator Input

MSK 23 Mask, Ring Melody Input

DATA 24 Data Input

DCL 25 Data Clock Input

VRMC 26 Microcontroller Stabilized Power Supply

VREF 27 Reference Voltage (VCC/2)

DTMF 28 DTMF Filter7088A-01.TBL

SPEECH

The speech network includes :- a low noise transmit channel suitable for any kind

of microphone transducer. Softclipping on trans-mit line signal is provided by the chip.

- a low noise receive channel with symmetricaloutputs to be compatiblewith both piezoceramicand electrodynamic earpiece. An additional 6dBgain can be inserted in the receive channelthrough software control.

- a line length gain control (AGC) with startingpointof gainregulation fixedat 25mAlinecurrent ; slopeof gainregulationis externallyadjustablewith oneresistor.AGC can be removedby hardware(maxi-mum gain flat) or by software(-2dB flat).

The phone impedance and sidetone can be tuned

through external networks.

DTMF GENERATOR

The onboard DTMF generator fullfils the CEPTrequirementswith an external single pole filter.

RINGER

Up to 8 different tones can be generated by theTEA7088Aringer. The digital volume control of the

ringer can be performed through a specific com-mand (4 steps). A ring indication signal is providedto the microcontroller by the TEA7088A.If moretones are requested the input RM/MSK allows toinject tones generated by the microcontroller.

FURTHER ADVANTAGES

The microcontroller power supply is provided by theTEA7088A.The powersupply is specifically designedto copewitha longflash ora long groundkeyduration.

The TEA7088A is able to supply the necessarycurrent to an external speakerphone circuitTEA7540 and loudspea ker amplifier TEA7532

without any additional circuitry.Line current and reset indications are provided tothe microcontroller by t he TEA7088A.

The microcontroller drives the TEA7088A througha 2 wires serial interface.

TEA7088A

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ELECTRICAL CHARACTERISTICS

The block diagram is given in Figure 1.

The values of the different networks used in this datasheetare defined as followed :

- The return loss is adjusted by R10 of 600.- The transmit adjust gain network R8 is calculatedin order to have a gain of 46dB typical with ILS = 22mA.- The sidetone network ZST is set to be lower than 20dB (Vear/Vmic) on a 600 load on line.- The DC characteristics are set by a resistor of 82k between VL and VS.

Absolute Maximum Ratings

Symbol Parameter Value Unit

Authorized Voltage onPin 2 - RECINPin 3 - SNPin 8 - VCCPin 10 - IVLSPin 12 - VLPin 13 - VMC

Pin 17 - BUZPin 18 - VRINGPin 19 - RESPin 20 - PONPin 21 - RIPin 22 - OSCPin 23 - MSKPin 24 - DATAPin 25 - DCLPin 26 - VRMC

1312116

126

VRING +0.3, GND -0.327

VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3VRMC +0.3, GND -0.3

5

VVVVVV

VVVVVVVVVV

ILINE Line Current 120 mA

IRING Ring Current 50 mA

Toper Operating Temperature -25, +70 C

Tstg Storage Temperature -55, +150 C

Tj Junction Temperature -25, +150 C 7088A-02.TBL

DC Characteristics (Tamb = 25C ; Logic in Default Mode unless otherwise noted)

Symbol Parameter Test Conditions Min. Typ. Max. Unit

VL Line Voltage- In Speech and DTMF Mode

- In Mask Mode

Test 1IL = 22mAIL = 90mAIL = 22mA

46.7

4.67.5

5.28.3

3

VVV

IVRMC Stabilized Supply Voltage- Output Current

Test 1, IL = 22mA1.5 mA

VRMC - Output Voltage IRMC = 1.5mA 3.15 3.35 3.55 V

IVMC Unstabilized Supply Voltage- Start up Current- Output Current

Test 1, IL = 22mAVMC = 2.5V, IVRMC = 1.5mAV

MC= 3.6V, I

VRMC= 0mA

10 153

mAmA

ILS Line Current Source Supply Test 1, VLS = 0V ; VMC = 3.6VIL = 22mAIL = 90mA

1067

1475

1882

mAmA

The line current source supply depends of IL :- For IL < 20mA: ILS (mA) = 0.765 x IL (mA) - 1.4mA- For IL > 20mA: ILS (mA) = 0.92 x IL (mA) - 4.5mA

On this pin the maximum output level is : V10 = V12 - (1.2 + 10 x ILS) and V10 < 6V

TEA7088A

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ELECTRICAL SPECIFICATIONS (continued)

AC Characteristics (Tamb = 25C ; RL = 600 ; Logic in Default Mode unless otherwise noted)


R1 Return Loss Test 2, IL = 22mAf = 300/3400Hz, VAC = -10dBV

17 dB

Transmit Characteristics(Tamb = 25C ; RL = 600 ; f = 1kHz ; Logic in Default Mode unless otherwise noted)


Gtx

GtxlGtxs

Microphone Gain Test 3, Vm = -55dBVR8 = 1.3k, R25 = 3.9k

IL = 22mAIL = 90mA

4538

4640

4742

dBdB

Zmic Microphone Input Impedance between MIC1 & MIC2 32 40 48 k

Ntx Noise Test 3, 2k on microphone inputs,IL = 22mA

-76 dBmp

Mmic Microphone Mute Test 3, Vm = -55dBV, IL = 22mA 60 dB

DtxVL Max.

Soft Clipping- Distortion- Maximum Level on Line

Test 3, IL = 22mA, see Figure 2Vm = -41dBVVm = -34dBV 1.5

2 %Vp

The maximum gain Gtl is adjustable between 44and 56dB with R8 :

Gtxl = 20log820

R10//RL + R11

R8 // 50k

The AGCvariation is programmedwithoneresistorconnected on Pin AGC. ISL is the line current atwhich the gain must be decreasedby 6dB.

R25 () =300

ISL 5mA(R25 > 2.6k)

For line current lower than ILL or higher than ISL,The transmit and receive gains have a constantvalue.

If no resistor or a resistor higher than 300k isconnected on Pin AGC, the gain is constant andequal to Gtxl and Grxl. 0.5dB.

AGC can be inhibited also through MCU code010100. In this case Tx and Rx gains are fixed2dB lower than the maximum gain.

The minimum saturation voltage of the TEA7088Arespect to ground is 2.2V. On long line, when thevoltage over TEA7088A is low, the softclippingfunction automatically limits the AC dynamic toavoid to reach the 2.2V limit on TEA7088Arespectto ground.

0.1 1 10 1000.1

1

10

Threshold

Level

Vmicrophone peak (mV)

VACpeakonline(V)

-2

-5

-10

-15

7088A-03.EPS

Figure 2 : Softclipping

0 20 40 60 80 1000

2

4

6

10

VL(Pin

12)(V)

VAC

peak

IL

(mA)

8

VAC peak

7088A-04.EPS

Figure 3

TEA7088A

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Receive Characteristics (Tamb = 25C ; RL = 660 ; f = 1kHz)


Eff SidetoneEff = (Vear+ - Vear -) /Vm

Test 3, Vm = -55dBV, IL = 22mA,R14 = 10k, R17= 15k

22.5 dB

GRXlGRXs

Gain in Symmetric ModeGrx = (Vear+ - Vear-) / VL

Test 6, VL = -14.5dBV, R14 = 10k,R17 = 15k, R25 = 3.9k

IL = 22mAIL = 90mA

0.7-6 1.7

-42.7-2

dBdB

Dr Distortion Test 4, Rear = 300, IL = 22mAVear = -12dBVVear = -8dBV

25

%%

Nr Noise Test 4, IL = 22mA -76 dBmp

Vear(010010)

Earphone Mute IL = 22mA, VL = -14.5dBV 60 dB

Zout Output Impedance 20

Automatic Gain Control Inhibition (Tamb = 25C ; RL = 660 ; f = 1kHz no AGC mode selected)Symbol Parameter Test Conditions Min. Typ. Max. Unit

GtpGrp

Transmit GainReceive Gain

Test3 & Test4, IL = 22 to90mACode : 010100Vm = -55dBVVL = -14.5dBV

Gtxl -3Grxl -3

Gtxl -2Grxl -2

Gtxl -1Grxl -1

dBdB

Ring Characteristics (Tamb = 25C)Symbol Parameter Test Conditions Min. Typ. Max. Unit

VThri ONVThri OFF

Ringing Threshold Voltage Test 5 a/bRI high (see Figure 4)Rl low (see Figure 4)

155

209

VV

ICRing Internal Consumption in Ring

Mode

VRING = 10V 1 1.2 mA

VRMC Microprocessor Supply Voltage 3.45 3.75 4.05 V

tRON Rise Time IRING = 10mA 100 ms

VRING Internal Zener Voltage 27 V

Vbout Buzzer VoutFreq = 1312HzFreq. Code 001111

VRING = 27Vzener (see Figure 5)Level Code (011111)Level Code (011110)Level Code (011101)Level Code (011100)

124.42.2

1

135.62.81.4

13.56.73.41.8

VRMSVRMSVRMSVRMS

Vbout

7088A-06.EPS

Figure 5 : Ringer Output Waveform

OFF

ON

RingerStatus

VOFF VON V

RingerThreshold (VTHRI)7088A-05.EPS

Figure 4 : Ringer Hysteresis Ringer

TEA7088A

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DTMF Generator (Tamb = 25C ; RL = 660)


Amf Tone Frequency Accuracy Test 6 Pin Oscfclock = 1.79MHz oscillator offorResonator : 3.58MHz oscillator onC13 =100nF, IL = 22mA

- 0.4 0.4 %

LlfLhf

Low Freq. Group Line LevelHigh Freq. Group Line Level

-10-8

-8.5-6.5

-7-5

dBmdBm

Pmf Preemphasis HF/LF +1 +2 +3 dB

tDONtDOFF

Rise TimeDecay Time

55

msms

Cmf DTMF Confidence Tone :Earphone level (low freq.)Earphone level (high freq.)

1317

1722

2127

mVmV

- Unwanted Harmonics Level (see Figure 6)

100 1k 10k 100k 1M-90

-70

-50

-30

Vline(dBm)

(Hz)7088A-07.EP

S

Figure 6 : Unwanted Harmonics Level in DTMF

VREFI

IStart-up

ISpeech

VL

I (In Ring)

18

VRING

26

VRMC (3.4V)

13

C15

10 F

P

+ LCD

C10

47 F5.6V

VMC

Battery

kIL

7088A-08.EPS

Figure 7 : Microcontroller Interface

TEA7088A

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MICROCONTROLLER INTERFACE WITH TEA7088A

All inputs can be driven by a Low level max. of0.1 x VRMC and a high level min. of 0.9 x VRMC.

Inputs MSK, DCL and DATA have internal pull-upresistors of 120k and input OSC has a internalpull up of 240k.

All outputs can drive a 1mA typical.

Power Supply

The microcontroller is power supplied by a 3.4Vregulated supply (VRMC) and by an unregulatedpower supply (VMC).

The two supplies are connected through a serialregulator.The unregulatedpower supply (VMC) hasa DCvoltageequalto: V12 - 0.6V andmust be lower

than 6V. It is also possible to connect a battery atPin VMC and use the regulated output at Pin VRMCto supply a LCD driver.

The current consumption on the serial regulatorhas a typical value of 60A.

Power ON (PON)

TheTEA7088Ageneratesa poweron signal (PON)as soon as the voltage on Pin VRMC is higher than2.6V (0.75 x VRMC final)and the line current is pre-sent.

Note : Du ri ng t he b re ak p eri od i n t he

loopdisconndect and Flash mode andduring the exchange line break, the powerONsignal goes to lowlevel. Maximum delayfor Pon decay edge after ILine goes to zerois 50ms (with C8 = 47F, C 11 = 1F,C27 = 10F).

Reset

The TEA7088Agenerates a rise edge Reset signalas soon as the logic power supply is higher than2.6V (0.75 x VRMC final).

RESET remains high until VRMC decreases below2.5V or the RESET control code is received. InRing, RESET is identical to RI output.

Only new positive edge PON, derived on openingand closing the line, is forcing the default modeagain. The Reset control code is only active inspeech mode.

Serial Bus Interface (Data and Clock)

The serial bus uses 6 bits. Astandard8 bit buscan

be used, bits a6 and a7 are not take in account bythe TEA7088A. Different types of codes are used :

a) The Ring Control Code :- Ring start up- Output level codes

b) The Operating Code :- Speech- Dialing- Microphone mute- Earphone/Microphonemute

c) The Data Codes (DTMF, ring frequencies) :Those data codes are stored inside the

TEA7088Aand are used as soon as the dialingcode or the ring start code is received.

d) The Configuration Code :- AGC / no AGC (toggle)- No mask / mask (Low DC in make) (toggle)- Normal gain / normal gain +6dB, on receive

channel (toggle)- 1.79MHz external clock / 3.58MHz internal

oscillator (toggle)Those configuration codes are Flip-Flopcodes.For instance : The first time that the+6dB codeis sent, the receive gain increases of +6dB.

If the same code is sent again, the receive gaingoes back to normal value. In the same way the3.58MHz internal oscillator can be switchedOFF with a second transmission of the propercode.

e) The RESET Code :Reset code from theMCU will resetinternallogicof TEA7088A to default mode and will induceTEA7088Ato generate a RESET status lowto the MCU on Pin 19.Warning : the RESET code deactivates theserial bus interface which is reactivated onlyafter a ON-HOOK/OFF-HOOK sequence.

f) The INITIALIZATION Code :Initialization code from the MCU will reset theinternal logic of TEA7088A to default mode, butthe TEA7088Awill not generatereset commandto the MCU on Pin 19.

TEA7088A

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IL

VMC5

2.7

VRMC3.42.6

PON

RESET

t

t

t

t

t

A AB C D DEWitho ut us ing the RESET Code th rough th e Serial Bus Interfac e

Us ing the RESET Code throu gh the Se rial Bus Interfac e

IL

VMC5

2.7

VRMC3.42.6

PON

RESET

A B C D DE DF A

t

t

t

t

t

tdtd

A : ON-HOOK

B : START UP + SP EECH

C : PULSE DIALING

D : SPE ECH or DTMF

E : LINE BRE AKEXCHANGE DURATION

F : LINE BREAK EXCHANGE DURATION > tdtd : DELAYFIXED BY THE MICROCONTROLLER

2.5V

2.5V

Reset controlcode (010111)

sent on the serialbus

7088A-09.EPS

Figure 8 : Reset and Power ON

MICROCONTROLLER INTERFACE WITH TEA7088A (continued)

TEA7088A

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The Start Up Conditions of the TEA7088A

As soon as RESETis high and before sending any

code the circuit is in the following default configu-ration :- Speech- No mask- AGC ON in transmit and receive channels- Normal gain on receive channel- 1.79MHz input clock (oscillator in stand by)

6 bit Codes

Between two DTMF or ring frequencies, introduc-ing a Mute or speech code implies to wait 1ms toend the sinewave or square period.

DTMF DialingTo dial in DTMF the following sequence of codesmust be sent :

DTMF Frequency code : 00XXXXDialing Mode code : 010001Mute or SPEECH code : 010010 or 010000

The duration of the DTMF signal is fixed by thedelay between Dialing mode code and MUTE orSPEECH code.

Pulse Dialing

The pulse dialing function is performed by the

microcontroller through the high voltage stage.

The MAKE voltage over the TEA7088A during

dialing can be reduced by sending the mask code0010101. To recover the normalspeech voltage atthe end of dialing the mask code must be sentagain.

If the mask code is not used the voltage over theTEA7088Aduring dialing is the same as in speechmode.

Ring Indicator (RI)

In ring mode TEA7088A generates a high logiclevel on Pin RI as soonas the voltage on PinVRINGis higherthan VTHRI ON(19VTyp.),andthevoltage

on VRMC is higher than 3.4V.When the voltage on VRMC becomes higher than2.6V, RESET signal becomes also high.

Mask Input (MSK)

MSK input must be high by default (Figure 10).

In speech configuration forcing MSK input to lowlevel will have same functionality than the MASKcode.

For ring mode when it is necessary to send otherfrequencies than the 8 basic ones, this input allowsto drive the buzzer output.


a 0 a1 a2 a3 a4 a5 a6

t1 t2 t4 t5

CLK Data

Data

S ynchro Datas with a Change During CLK= 1

t3 t3t0

t0, t1, t2, t3, t4, t5 > 1s7088A-10.EPS

Figure 9 : DATA/CLOCK Timing

IL

MSK

PULSE MODE OTHER MODES OTHER MODESFLASH MODE

7088A-11.EPS

Figure 10 : MASK Timing

TEA7088A

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CodesKeyboard Remarks

a5 a4 a3 a2 a1 a0

0000000000000000

0000000000000000

0000000011111111

0000111100001111

0011001100110011

0101010101010101

21A387C954B60*D#

1336Hz + 697Hz1209Hz + 697Hz1633Hz + 697Hz1477Hz + 697Hz1336Hz + 852Hz1209Hz + 852Hz1633Hz + 852Hz1477Hz + 852Hz1336Hz + 770Hz1209Hz + 770Hz1633Hz + 770Hz1477Hz + 770Hz1336Hz + 941Hz1209Hz + 941Hz1633Hz + 941Hz1477Hz + 941Hz

In DTMFDialing

00000000

00000000

00001111

00001111

00110011

01010101

822Hz Ring Signal744Hz Ring Signal1005Hz Ring Signal909Hz Ring Signal1187Hz Ring Signal1074Hz Ring Signal1451Hz Ring Signal1312Hz Ring Signal

In RingMode

0000

1111

0000

0000

0011

0101

Speech ModeDialing Mode or Ring StartEarphone & Microphone MuteMicrophone Mute

0 1 0 1 0 1 Mask/No Mask

0 1 0 1 1 0 +6dB Normal/+6dB on Receive Channel

0 1 0 1 1 1 Reset Pin Control

1 1 1 0 1 0 Initialization Code

0 1 0 1 0 0 AGC / No AGC

1 0 1 0 0 0 1.79MHz Ext Clock & Oscillator Stand by / 3.58MHz Ceramic (toggle)

0 1 1 1 0 0 Minimum Ring Level (level 1)

0 1 1 1 0 1 Intermediate Low Ring Level (level 2)

0 1 1 1 1 0 Intermediate High Ring Level (level 3)

0 1 1 1 1 1 Maximum Ring Level (level 4)7088A-03.TBL


TEA7088A

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7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS 47 F

1N4148

VCCIVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F300

15k

10k

1.3k

VREF

10 F24V

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82k

33

C2

4.7nF 1.6k

100nF

600

100 F

IL

15k

Sidetone

VCC

7088A-12.EPS

Figure 11 : Test Circuits - Test 1 (VL / VRMC / VMC / IVMC / ILS)

7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS 47 F

1N4148

VCC

IVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F

300

15k

10k

1.3k

VREF

10 F

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82k

33

C24.7nF 1.6k

100nF

100 F

IL

15kSidetone

VCC

IAC

VAC

Z =I

AC

RI= 20 logZ + 600

Z - 600

24V

VAC

7088A-13.EPS

Figure 12 : Test 2 (R1)

TEA7088A

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13/17

7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS

47 F

1N4148

VCC

IVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2

F

30 0

15 k

10k

1.3k

VREF

10 F24 V

47

47nF

10 0 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82k

33

C2

4.7nF 1.6k

100nF

600

100 F

IL

15 k

Sidetone

VCC

Vm

Gtl/Gts = 20 logV12Vm

Mmic = 20 logV12 (010000)

V12 (010011)Eff= 20 log

Vea rVm

Vea r

7088A-14.EPS

Figure 13 : Test 3 (Gtl / Gts / Zmic / Nt / Mmic / Dt / Vlmax / Eff)

7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS 47 F

1N4148

VCCIVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F

300

15k

10k

1.3k

VREF

10 F

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82k

33

C2

4.7nF 1.6k

100nF

100 F

IL

15kSidetone

VCC

IAC

VAC

Grl/Grs = 20 log

24V

Vear

Vear

V127088A-15.EPS

Figure 14 : Test 4 (Grl / Grs / Dr / Mear / Nr)

TEA7088A

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7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

Vbout

47 F

1N4148

VCCIVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F

300

15k

10k

1.3k

VREF

10 F

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

62 013V

1 F

82k

33

C2

4.7nF 1.6k

100nF

15k

Sidetone

VCC

24 VVthri

7088A-16.EPS

Figure 15 : Test 5a (Vthri)

7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS 47 F

1N4148

VCCIVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F

300

15k

10k

1.3k

VREF

10 F

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82k

33

C2

4.7nF 1.6k

100nF

IRING

15kSidetone

VCC

Vbout

6 bit serial code (0111XX/Fi/010001) ; OSCIN = 1.79MHz external clock (default mode)or 3.58MHz externa l ceram ic/crystal (with code 101000 to s elect internal oscillator)

7088A-17.EPS

Figure 16 : Test 5b (Vbout)

TEA7088A

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15/17

7GTR1

2 3

4

5

6

8

9

10

11 12

13

14

15

16

17

18

19202122232425

26

27

28

ILS 47 F

1N4148

VCCIVLS

MIC1

MIC2

EAR-

EAR+

GREC

470nF

2k

2.2 F

300

15k

10 k

1.3k

VREF

10 F

47

47nF

100 F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

10 F

100nF

10 F

560k

100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN V

SVL

SN

3.9k

VREF

47 F

620

13V

1 F

82 k

33

C2

4.7nF 1.6k

100nF

60 0

100 F

IL

15k

Sidetone

VCC

6 bits erial code (00XXXX/Fi/010010) ; OSCIN = 1. 79MHz external clock (default mode)or 3.58MHz external ceramic/crystal (with code 101000 to select internal oscillator)

7088A-18.EPS

Figure 17 : Test 6 (DTMF)

TEA7088A

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1

2

3

S

4

5

6

M

7

8

9

L

*

0

#

R

7

GTR

1

2

3

4

56

8

9

10

11

1

2

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

C30

47nF

VCC

IVLS

MIC1

MIC2

EAR-

EAR+

GREC

C2247nF

R17

15k

R81.3k

VREF

C16

10F

D3

24V

47

Buzzer

C10

470F

VRING

BUZ

VMC

VREF

DTMF

VRMC

SOFT

AGC

C14

47nF

C13100nF

R4560k

C3100nF

VCC

DCL

DATA

MSK

OSC

RI

PON

RESET

GND

TEA7088A

VCC

RECIN

VS

VL

SN

R25

VREF

C8

47F

R10

620

D213V

C11

1F

R1282k

R1133

C

2

4.7nF

R13300

C12

100nF

R6

Sidetone

VCC

R21

2k

C2147nF

R1410

k Handset

C17

2.2nF

C261F

C5

R5

Impedance

R151k

C154.7F

R2822k

R27

5.6

Q1BSS92

D116.2V

3.58MHz

X2

R29

22k

R2330k

Q3

BF393

D5BAT42

C

18

3

0pF

X

1

C19

30pF

MCU

D7

D6

D8

D9

4x1N4

004

B

SW

1B

SW1A

R40

1k

C1820nF

A7088A-19.EPS

TYPICAL APPLICATION

TEA7088A

16/17


17/17

PM-SO28.EPS

PACKAGE MECHANICAL DATA28 PINS - PLASTIC PACKAGE

DimensionsMillimeters Inches

Min. Typ. Max. Min. Typ. Max.

A 2.65 0.104

a1 0.1 0.3 0.004 0.012

b 0.35 0.49 0.014 0.019

b1 0.23 0.32 0.009 0.013

C 0.5 0.020

c1 45o (Typ.)

D 17.7 18.1 0.697 0.713

E 10 10.65 0.394 0.419

e 1.27 0.050

e3 16.51 0.65

F 7.4 7.6 0.291 0.299

L 0.4 1.27 0.016 0.050

S 8o

(Max.)SO28.TBL

Informationfurnished is believed to be accurateand reliable.However, SGS-THOMSON Micr oelectronics assumesno responsibilityfor the consequences of use of such information nor for any infringementof patentsor other rights of third parties which may result

from itsuse. No licence is granted by implication orotherwise underany patent or patent rightsof SGS-THOMSON Microelectronics.Specifications mentioned in this publication are subject t o change without notice. This pu blication supersedes and replaces allinformationp reviouslysupplied. SGS-THOMSON Microelectronics products areno t authorized for use as criticalcomponents in lifesupport devices or systems without express written approval of SGS-THOMSON Microelectronics.

1998 SGS-THOMSON Microelectronics - All Rights Reserved

Purchase of I2C Components of SGS-THOMSON Microelectronics, conveys a license under the PhilipsI

2C Patent. Rights to use these components in a I

2C system, is granted provided that the system conforms to

the I2C Standard Specifications as defined by Philips.

SGS-THOMSON Microelectronics GROUP OF COMPANIESAustralia - Brazil- Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Morocco

The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.

TEA7088A

17/17

Documents

Low-range Phone Dedicated Chip