Datasheet TEA7088A Datasheet (SGS Thomson Microelectronics)

LOW-RANGE PHONE DEDICATED CHIP

.

RING

- GENERATION OF 8 MELODYTONES
(Includingthe 3 GermanMelody Tones)

- 4 STEPS DIGITAL CONTROL ON THE AM­PLIFIEROUTPUT LEVEL

.

SPEECH

- TRANSM I TGAINEXTERN ALLYADJUST ABL E

- RECEIV IN GGAINEXTER NALLYADJUSTA B LE

- AGCSLOPEEXTERN A LLYPROGRAMM ABLE

- SOFTCLIPPINGON SENDING CHANNEL

- RECEIVE AMPLIFIER FOR PIEZO OR
ELECTRODYNAMIC TRANSDUCER

- +6dB MODE ON RECEIVECHANNEL

- LINE POWER MANAGEMENT

.

DIALING

- DTMF GENERATOR

- LOW DC MASK DURING MAKE PERIOD
THROUGH MICROCONTROLLER SERIAL
BUS INTERFACE

.

MICROCONTROLLER INTERFACE

- 1.79MHzCLOCKOR3.58MHzOSCILLATOR
INPUT

.

MICROCONTROLLER POWER SUPPLY

.

MICROCONTROLLER CONTROL INTER­FACE INCLUDING SERIALBUS

.

LINE CURRENT EXTRACTOR FOR SUPPLY
OF EXTERNAL PERIPHERALS

(Plastic Package)

ORDER CODE : TEA7088AFP

PIN CONNECTIONS

SOFT

RECIN

SN

AGC

1
2
3
4

TEA7088A

SO28

28
27
26
25

DTMF

V

REF

V

RMC

DCL

DESCRIPTION

The TEA7088A is a Telephone Analog Front End
device, TAFE, which integrates the three basic
functionsof a standardtelephoneset :

- Speechnetwork,

- DTMF generator,

- Ringer generatoron buzzer.
A complete telephone set can be designed using

TEA7088A associated with a low cost microcon­troller.

January 1998

MIC1

MIC2

GTR

V

GND

IVLS

V

V

V

GREC

5
6
7
8

CC

9
10
11

S

12

L

13

MC

14

24
23
22
21
20
19
18
17
16
15

DATA

MSK
OSC
RI

PON

RES

V

RING

BUZ

EAR+

EAR-

7088A-01.EPS

1/17

TEA7088A

SPEECH

Thespeech network includes :

- a lownoisetransmitchannel suitablefor anykind
of microphonetransducer. Softclippingon trans­mit line signal is provided by the chip.

- a low noise receive channel with symmetrical
outputs to be compatiblewith both piezoceramic
and electrodynamicearpiece. An additional 6dB

RINGER

Up to 8 different tones can be generated by the
TEA7088Aringer.The digitalvolume controlof the
ringer can be performed through a specific com­mand(4 steps).A ringindicationsignal is provided
to the microcontroller by the TEA7088A.If more
tones are requested the input RM/MSK allows to

inject tones generatedby the microcontroller.
gain can be inserted in the receive channel
throughsoftware control.

- a linelengthgain control(AGC)withstartingpoint
ofgainregulationfixedat25mAlinecurrent;slope
of gainregulationis externallyadjustablewithone
resistor.AGCcan beremovedbyhardware(maxi­mumgain flat) or by software(-2dBflat).

The phoneimpedanceand sidetone can be tuned
throughexternal networks.

FURTHERADVANTAGES

The microcontroller power supply is provided by the
TEA7088A.Thepowersupplyisspecif i cal l ydesigned
tocopewitha longflas horalonggroundkeyduration.

The TEA7088A is able to supply the necessary
current to an external speakerphone circuit
TEA7540 and loudspeaker amplifier TEA7532
without any additionalcircuitry.

Line current and reset indications are provided to

DTMF GENERATOR

The onboard DTMF generator fullfils the CEPT
requirementswith an externalsinglepole filter.

the microcontrollerby theTEA7088A.
The microcontroller drivesthe TEA7088Athrough

a 2 wires serial interface.

PIN DESCRIPTION

Name Pin N° Description

SOFT 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

V

CC

GND 9 Ground

IVLS 10 Line Current Source Power Supply

V

S

V

L

V

MC

GREC 14 Receive Gain Adjustment

EAR- 15 Negative Earphone Output

EAR+ 16 Positive Earphone Output

BUZ 17 RingerBuzzer 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 DataClock Input

V

RMC

V

REF

DTMF 28 DTMF Filter

2/17

8 Transmit and Receive Part Power Supply

11 Voltage Stabilizer
12 Positive Line
13 Unregulated Microcontroller Power Supply

26 Microcontroller Stabilized Power Supply
27 Reference Voltage (VCC/2)

7088A-01.TBL

Figure1 : BlockDiagram

TEA7088A

CC

V

Sidetone

R13

C30

To Line

To P

C12

C1

RI

RECIN SN

IVLSV

21

2

C15

C16

R40 + R15

V

18

TEA7088A

SUPPLY

RING POWER

LINE CURRENT

POWER SUPPLY

RMCVRING

26

BUZZER

SUPPLY

LOGIC POWER

BUZ

17

AMPLIFIER

&AGC

SIDETONE

MUTE

AGC

RING

CONTROL

C10

MC

V

13

GENERATOR

SERIAL

REGULATOR

MSK

232425

DTMF

GENERATOR

To P

DCL

DATA

P

INTERFACE

1.79MHz

EXT. CLOCK

OSC

OSCILLATOR /2

3.58MHz

RESONATOR

1920 22

To P

CONTROL

PON & RESET

REF

V

PON RES

GND

9

To Line

C8

R10

R11

V

CC

L

R12

8310

12

V

C11

MUTE

DTMFAGC

28

567

MIC1

AGC

MIC2

Microphone

4

R25

CC

V

C3

C3

KVL

SOFT

R4

IN

V

1

GTR

R8

VSTAB

Earphone

Amplifier

EAR-

Earphone

-1

15

REF

V

11

27

S

REF

V

R14

14

GREC

16

EAR+

R17

C14

7088A-02.EPS

3/17

TEA7088A

ELECTRICALCHARACTERISTICS

Theblock diagram is given in Figure 1.
Thevalues of the differentnetworks used in this datasheetare defined as followed:

- The return loss is adjusted by R10 of 600Ω.

- The transmitadjust gainnetworkR8 is calculatedinorder to havea gainof46dB typicalwith I

- The sidetone networkZST is set to be lower than 20dB (Vear/Vmic)on a 600Ωloadon line.

- The DC characteristicsare setby a resistorof 82kΩ betweenV

and VS.

L

Absolute MaximumRatings

Symbol Parameter Value Unit

I

LINE

I

RING

T

T

oper

stg

T

Authorized Voltage on

Pin 2 - RECIN
Pin 3 - SN
Pin 8 - V
Pin 10 - IVLS
Pin 12 - V
Pin 13 - V
Pin 17 - BUZ
Pin 18 - V
Pin 19 - RES
Pin 20 - PON
Pin 21 - RI
Pin 22 - OSC
Pin 23 - MSK
Pin 24 - DATA
Pin 25 - DCL
Pin 26 - V

CC

L
MC

RING

RMC

V
V

V
V
V
V
V
V

RING

RMC
RMC
RMC
RMC
RMC
RMC
RMC

Line Current 120 mA
Ring Current 50 mA
Operating Temperature -25, +70 °C
Storage Temperature -55, +150 °C
Junction Temperature -25, +150 °C

j

13
12
11

6

12

6

+0.3, GND -0.3

27
+0.3, GND -0.3
+0.3, GND -0.3
+0.3, GND -0.3
+0.3, GND -0.3
+0.3, GND -0.3
+0.3, GND -0.3
+0.3, GND -0.3

5

LS

=22mA.

V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V

7088A-02.TBL

DC Characteristics(T

=25°C; Logic in Default Modeunless otherwise noted)

amb

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

I

VRMC

V

RMC

I

VMC

I

LS

L

Line Voltage

- In Speech and DTMF Mode

- In Mask Mode
Stabilized Supply Voltage

- Output Current

- Output Voltage IRMC = 1.5mA 3.15 3.35 3.55 V
Unstabilized Supply Voltage

- Start up Current

- Output Current
Line Current Source Supply Test 1, VLS=0V;VMC= 3.6V

Test 1

= 22mA

I

L

= 90mA

I

L

= 22mA

I

L

Test 1, IL= 22mA

V

MC

V

MC

= 22mA

I

L

= 90mA

I

L

= 22mA

L

= 2.5V, I
= 3.6V, I

Test 1, I

VRMC
VRMC

= 1.5mA
= 0mA

4

6.7

4.6

7.5

5.2

8.3
3

1.5 mA

10 15

3

10
67

14
75

18
82

Theline current sourcesupply dependsof IL:

- For I

- For I
Onthis pin the maximumoutput levelis : V

4/17

< 20mA: ILS(mA)= 0.765 x IL(mA)- 1.4mA

L

> 20mA: ILS(mA)= 0.92x IL(mA)- 4.5mA

L

10=V12

- (1.2+ 10 x ILS) and V10<6V

V
V
V

mA
mA

mA
mA

TEA7088A

ELECTRICALSPECIFICATIONS(continued)
AC Characteristics(T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

R1 Return Loss Test 2, I

TransmitCharacteristics

(T

=25°C; RL= 600Ω ; f = 1kHz ; Logicin Default Mode unlessotherwisenoted)

amb

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Gtx

Gtxl

Gtxs
Zmic Microphone Input Impedance between MIC1 & MIC2 32 40 48 kΩ

Ntx Noise Test 3, 2kΩ on microphone inputs,

Mmic Microphone Mute Test 3, V

Dtx

V

Max.

L

Microphone Gain Test3, V

Soft Clipping

- Distortion

- Maximum Level on Line

=25°C;RL= 600Ω ; Logic in Default Mode unless otherwisenoted)

amb

= 22mA

f = 300/3400Hz, V

R8 = 1.3kΩ, R25 = 3.9kΩ

I

Test 3, I

L

= -55dBV

m

= 22mA

I

L

= 90mA

I

L

= 22mA

L

= -55dBV, IL= 22mA 60 dB

m

= 22mA, see Figure 2

L

= -41dBV

V

m

= -34dBV 1.5

V

m

= -10dBV

AC

17 dB

4538464047

42

-76 dBmp

2%

dB
dB

Vp

Figure2 : Softclipping

10

Threshold

Level

1

peak on line (V)

AC

V

0.1

0.1 1 10 100
V

microphon e

peak(mV)

Figure3

10

8

6

4

(Pin 12) (V)

L

V

2

VACpeak

0

0 20 406080100

IL(mA)

-15

-10

-5

-2

VACpeak

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

Gtxl =

20log

820⋅




R10// R

R8 // 50k

+ R11

L

Ω



TheAGCvariationisprogrammedwithoneresistor
connected on Pin AGC. I

is the line current at

SL

whichthe gain must be decreasedby 6dB.

R25 (Ω) =

I

SL

300

− 5mA

For line current lower than I
The transmit and receive gains have a constant

7088A-03.EPS

value.

(R25 > 2.6kΩ)

or higher than ISL,

LL

If no resistor or a resistor higher than 300kΩis
connected on Pin AGC, the gain is constant and
equal to Gtxl and Grxl.±0.5dB.

AGC can be inhibited also through MCU code
”010100”. In this case Tx and Rx gains are fixed
2dB lower than the maximumgain.

The minimumsaturationvoltageof theTEA7088A
respect to ground is 2.2V. On long line, when the
voltage over TEA7088A is low, the softclipping
function automatically limits the AC dynamic to
avoidto reachthe 2.2Vlimiton TEA7088Arespect

7088A-04.EPS

to ground.





5/17

TEA7088A

ELECTRICALSPECIFICATIONS(continued)
ReceiveCharacteristics (T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

E

G

G

Dr Distortion Test 4, Rear = 300Ω,I

Nr Noise Test 4, I

Vear

(010010)

Zout Output Impedance 20 Ω

Sidetone

ff

Eff = (Vear
Gain in Symmetric Mode

Grx = (Vear

RXl
RXs

+

- Vear-) /Vm

+

- Vear-)/V

Earphone Mute I

=25°C; RL=660Ω ; f = 1kHz)

amb

Test 3, V
R14 = 10kΩ, R17 = 15kΩ

= -55dBV, IL= 22mA,

m

Test 6, VL= -14.5dBV, R14 = 10kΩ,

L

R17 = 15kΩ, R25 = 3.9k

= 22mA

I

L

= 90mA

I

L

Vear = -12dBV
Vear = -8dBV

= 22mA -76 dBmp

L

= 22mA, VL= -14.5dBV 60 dB

L

Ω

= 22mA

L

0.7

-6 1.7

22.5 dB

2.7

-4

-2

2
5

dB
dB

%
%

Automatic Gain Control Inhibition (T

=25°C; RL= 660Ω; f = 1kHz no AGC mode selected)

amb

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Gtp
Grp

Transmit Gain
Receive Gain

Ring Characteristics (T

amb

=25°C)

Test3 &Test4, I
Code : 010100

= -55dBV

V

m

= -14.5dBV

V

L

= 22to 90mA

L

Gtxl -3
Grxl -3

Gtxl -2
Grxl -2

Gtxl -1
Grxl -1dBdB

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Ringing Threshold Voltage Test 5 a/b

V

Thri ON

V

Thri OFF

I

CRing

V

t

RON

V

RING

V

RMC

Internal Consumption in Ring
Mode

Microprocessor Supply Voltage 3.45 3.75 4.05 V
Rise Time I
Internal Zener Voltage 27 V
Buzzer V

bout

Freq = 1312Hz

out

Freq. Code 001111

Figure4 : RingerHysteresisRinger

ON

RI high (see Figure 4)
Rl low (see Figure 4)

V

= 10V 1 1.2 mA

RING

= 10mA 100 ms

RING

15

5

VRING = 27Vzener (see Figure 5)

Level Code (011111)
Level Code (011110)
Level Code (011101)
Level Code (011100)

12

4.4

2.2

13

5.6

2.8

1

1.4

Figure 5 : Ringer OutputWaveform

20

9

13.5

6.7

3.4

1.8

V
V

V

RMS

V

RMS

V

RMS

V

RMS

6/17

Ringer

Status

OFF

V

OFF

RingerThreshold (V

THRI

V

bout

V

)

V

ON

7088A-05.EPS

7088A-06.EPS

TEA7088A

ELECTRICALSPECIFICATIONS(continued)
DTMF Generator(T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Amf Tone FrequencyAccuracy Test 6 Pin Osc

Llf

Lhf

Low Freq. Group Line Level
High Freq. Group Line Level

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

t

DON

t

DOFF

Rise Time
Decay Time

Cmf DTMF Confidence Tone :

Earphone level (low freq.)
Earphone level (high freq.)

– - Unwanted Harmonics Level (see Figure 6) ––––

Figure6 : UnwantedHarmonics Level in DTMF

-30

=25°C; RL= 660Ω)

amb

fclock = 1.79MHz oscillator off
or
Resonator :3.58MHzoscillatoron
C13 =100nF, I

= 22mA

L

- 0.4 0.4 %

-10

-8

-8.5

-6.5

-7

-5

5
5

13
17

17
22

21
27

dBm
dBm

ms
ms

mV
mV

-50

-70

Vline (dBm)

-90
100 1k 10k 100k 1M

(Hz)

Figure 7 : Microcontroller Interface

V

MC

13

Batte ry

C10

47 F

V

5.6V

REFI

7088A-07.EPS

V

RING

V

L

I

Speech

I

Start-u p

kIL

18

I(In Ring)

V

(3.4V)

RMC

26

C15
10 F P+LCD

7/17

7088A-08.EPS

TEA7088A

MICROCONTROLLER INTERFACE WITH TEA7088A

All inputs can be driven by a Low level max. of

0.1 x V

anda high level min. of 0.9 x V

RMC

Inputs MSK, DCL and DATA have internal pull-up
resistors of 120kΩand input OSC has a internal
pullup of 240kΩ.

Alloutputs can drivea ±1mA typical.

PowerSupply

The microcontroller is power supplied by a 3.4V
regulated supply (V
powersupply (V

MC

) and by an unregulated

RMC

).

The two supplies are connected through a serial
regulator.The unregulatedpower supply(V
aDCvoltageequalto: V

-0.6Vandmustbelower

12

than 6V.It is also possible to connect a battery at
PinV

and use the regulatedoutputat Pin V

MC

to supplya LCD driver.
The current consumption on the serial regulator

hasa typical value of 60µA.
PowerON (PON)

TheTEA7088Ageneratesa poweron signal(PON)
as soonas the voltage on Pin V

2.6V (0.75x V

final)andthe line currentis pre-

RMC

is higher than

RMC

sent.
Note : During the break period in the

loopdisconndect and Flash mode and
during the exchange line break, the power
ONsignalgoesto lowlevel.Maximumdelay
for Pon decay edge after I

goesto zero

Line

is 50ms (with C8 = 47µF, C11 = 1µF,
C27 = 10µF).

Reset

TheTEA7088Ageneratesarise edgeResetsignal
as soon as the logic power supply is higher than

2.6V (0.75x V
RESETremains high until V

RMC

final).

decreasesbelow

RMC

2.5V or the RESET control code is received. In
Ring,RESET is identical to RI output.

Only new positive edge PON, derivedon opening
and closing the line, is forcing the default mode
again. The Reset control code is only active in
speechmode.

RMC

MC

.

)has

RMC

Serial Bus Interface (Dataand Clock)
Theserial bususes 6 bits.Astandard8bit buscan

be used, bits a6 and a7 are nottake in accountby
the TEA7088A.Different typesof codes areused:

a) The Ring Control Code :

- Ring start up

- Outputlevel codes

b) The Operating Code :

- Speech

- Dialing

- Microphonemute

- Earphone/Microphonemute

c) The Data Codes (DTMF, ring frequencies) :

Those data c odes are stor ed inside the
TEA7088Aand are used as soon as the dialing
code or thering 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-Flop”
codes.
For instance : The first time that the+6dBcode
is sent, the receivegain increases of +6dB.
If the samecode is sent again, the receivegain
goesbackto normalvalue.In thesameway the

3.58MHz internal oscillator can be switched

OFF with a second transmission of the proper
code.

e) The RESET Code :

ResetcodefromtheMCUwillresetinternallogic
of TEA7088A to default mode and will induce
TEA7088Ato generatea ”RESET” status”low”
to the MCU on Pin 19.
Warning : the ”RESET” code deactivates the
serial bus interface which is reactivated only
aftera ”ON-HOOK/OFF-HOOK”sequence.

f) The INITIALIZATION Code :

Initialization code from the MCU will reset the
internallogic of TEA7088Ato default mode, but
theTEA7088Awillnot generatereset command
to the MCU on Pin 19.

8/17

MICROCONTROLLER INTERFACE WITH TEA7088A(continued)
Figure8 : Resetand Power ON

Without us ing the RESET Code through the Serial Bus Interface

I

AABCD DE

L

TEA7088A

V

MC

5

2.7

V

RMC

3.4

2.6

PON

RESET

Us in g the RESET Code through the Serial Bus Interface

I

AB CD DEDFA

L

V

MC

5

2.7

t

t

2.5V

t

t

t

t

V

RMC

3.4

2.6

PON

RESET

A:ON-HOOK
B : START UP + SPEECH
C : PULSE DIALING
D : SPEECH or DTMF
E : LINE B REAKEXCHANGE DURATION
F : LINE BREAK EXCHANGE DURATION > t
td: DELAYFIXED BY THE MICROCONTROLLER

d

tdtd

Re se t con trolcod e (010111 )

sent on the serialbus

t

2.5V

t

t

t

7088A-09.EPS

9/17

TEA7088A

MICROCONTROLLER INTERFACE WITH TEA7088A(continued)
TheStart Up Conditions of the TEA7088A

Assoon as RESETis highand beforesending any
code the circuit is in the following default configu­ration:

- Speech

- No mask

- AGC ON in transmit and receive channels

- Normalgain on receivechannel

- 1.79MHz input clock(oscillator in stand by)

microcontroller through thehigh voltage stage.
The ”MAKE” voltage over the TEA7088A during

dialing can be reduced by sending the mask code

0010101.To recoverthe normalspeech voltageat
the end of dialing the mask code must be sent
again.

If the mask code is not used the voltage over the
TEA7088Aduring dialingis the same asin speech
mode.

6 bit Codes

Between two DTMF or ring frequencies, introduc­ing a Mute or speech code implies to wait 1ms to
end the sinewaveor square period.

DTMF Dialing

To dial in DTMF the following sequence of codes
must be sent :

DTMF Frequencycode : 00XXXX
DialingMode code : 010001
Muteor SPEECHcode : 010010 or010000

The duration of the DTMF signal is fixed by the
delay between Dialing mode code and MUTE or
SPEECHcode.

PulseDialing

The pulse dialing function is performed by the
Figure9 : DATA/CLOCKTiming

t1 t2 t4 t5

t3 t3t0

CLK Data

Data

a0 a1 a 2 a3 a4 a5 a6

Ring Indicator(RI)

In ring mode TEA7088A generates a high logic
levelon PinRI as soonas thevoltageon PinV
ishigherthan V
on V

is higher than3.4V.

RMC

When the voltage on V

ON(19VTyp.),andthevoltage

THRI

becomes higher than

RMC

RING

2.6V,RESET signal becomes also high.

Mask Input (MSK)

MSK inputmust be high by default (Figure 10).
In speech configuration forcing MSK input to low

level will have same functionality than the MASK
code.

For ring mode when it is necessaryto send other
frequenciesthanthe 8basicones,this inputallows
to drive the buzzer output.

Synchro

Figure10 : MASK Timing

I

L

MSK

10/17

Datas with a Change During CLK= 1

PULSE MODE OTHER MODES OTHER MODESFLASH MODE

t0, t1, t2, t3, t4, t5 > 1µs

7088A-10.EPS

7088A-11.EPS

MICROCONTROLLER INTERFACE WITH TEA7088A(continued)

Codes

a5 a4 a3 a2 a1 a0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0

0
0
0
0

010101 Mask/No Mask
010110”+6dB” Normal/+6dBon Receive Channel
010111 Reset Pin Control
111010 Initialization Code
010100 AGC/NoAGC
101000 1.79MHz Ext Clock & Oscillator Stand by /

011100 MinimumRing Level (level 1)
011101 Intermediate Low Ring Level (level 2)
011110 Intermediate High Ring Level (level 3)
011111 Maximum Ring Level (level 4)

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0

1
1
1
1

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

0
0
0
0
1
1
1
1

0
0
0
0

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1

0
0
0
0
1
1
1
1

0
0
0
0

0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1

0
0
1
1
0
0
1
1

0
0
1
1

Keyboard Remarks

0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

0
1
0
1
0
1
0
1

0
1
0
1

”2”
”1”

”A”

”3”
”8”
”7”

”C”

”9”
”5”
”4”

”B”

”6”
”0”

”*”

”D”

”#”

1336Hz + 697Hz
1209Hz + 697Hz
1633Hz + 697Hz
1477Hz + 697Hz
1336Hz + 852Hz
1209Hz + 852Hz
1633Hz + 852Hz
1477Hz + 852Hz
1336Hz + 770Hz
1209Hz + 770Hz
1633Hz + 770Hz
1477Hz + 770Hz
1336Hz + 941Hz
1209Hz + 941Hz
1633Hz + 941Hz
1477Hz + 941Hz

822Hz Ring Signal
744Hz Ring Signal
1005Hz Ring Signal
909Hz Ring Signal
1187Hz Ring Signal
1074Hz Ring Signal
1451Hz Ring Signal
1312Hz Ring Signal

Speech Mode
Dialing Mode or Ring Start
Earphone & Microphone Mute
Microphone Mute

3.58MHz Ceramic (toggle)

TEA7088A

In DTMF

Dialing

In Ring

Mode

7088A-03.TBL

11/17

TEA7088A

Figure11 : Test Circuits- Test 1(VL/V

100 F

I

L

600

V

REF

560k

Ω

100nF
100nF

10 F

47nF

Ω

47 F

10 F

100 F

47

10 F24V

C2

4.7nF

620

V

CC

3.9kΩ

4

AGC

1

SOFT

26

V

RMC

28

DTMF

27

V

REF

13

V

MC

Ω

17

BUZ

18

V

RING

RMC/VMC

Ω

/ IVMC / ILS)

33

Ω

13V

82kΩ

1.6kΩ

Sidetone

15kΩ

1 F

100nF

RECIN

11 12

S

V

L

V

GTR

GREC

EAR+

SN

7

14

16

8

23

CC

V

TEA7088A

2.2 F

15

DCL

DATA

MSK

OSCRIPON

EAR-

MIC2

MIC1

IVLS

RESET

GND

19202122232425

9

2k

Ω

6

470nF

5

1N4148

10

I

47 F

LS

15k

300

1.3k

10k

V

CC

V

REF

Ω

Ω

Ω

Ω

V

CC

Figure12 : Test 2 (R1)

I

AC

100 F

12/17

I

L

V

Z=

REF

560k

100nF
100nF

10 F

47nF

24V

V

AC

I

AC

V

AC

47 F

Ω

C2

4. 7nF

10 F

100 F

47

Ω

10 F

RI = 20 log

620

V

Ω

CC

1 F

3.9kΩ

13V

RECIN

TEA7088A

DATA

MSK

11 12

S

V

OSCRIPON

4

1

SOFT

26

V

28

DTMF

27

V

13

V

17

BUZ

18

V

RMC

REF

MC

RING

V

CC

DCL

23

8

AGC

Z + 600

Z - 600

33

82kΩ

7088A-12.EPS

Ω

1.6kΩ

Sidetone

15kΩ

V

CC

100nF

15k

300

1.3k

10k

V

REF

Ω

Ω

Ω

Ω

L

V

GTR

GREC

EAR+

SN

7

14

16

2.2 F

15

EAR-

MIC2

2k

Ω

6

470nF

5

MIC1

1N41 48

10

IVLS

RESET

GND

19202122232425

9

I

LS

47 F

V

CC

7088A-13.EPS

Figure13 : Test 3 (Gtl / Gts / Zmic / Nt / Mmic/ Dt / Vlmax/ Eff)

33

Ω

0

F

10

I

L

600

V

REF

560k

Ω

100nF

Ω

47 F

C2

4.7nF

620

V

Ω

CC

13V

1

82kΩ

F

3.9kΩ

23

4

1

26

F

10

8

CC

AGC

V

SOFT
V

RMC

RECIN

11 12

S

V

100nF

28

DTMF

27

V

10 F

100

REF

13

V

F

47

Ω

MC

17

BUZ

TEA7088A

47nF

18

V

RING

V
V

12

12

DCL

(010000)
(010011)

DATA

MSK

Eff = 20 log

OSCRIPON

V

ear

V

m

19202122232425

Gtl/Gts = 20 log

V

12

V

m

10 F24V

Mmic = 20 log

Figure14 : Test 4(Grl / Grs/ Dr / Mear/ Nr)

13V

1 F

11 12

S

V

MSK

OSCRIPON

33

82k

Ω

Ω

V

19202122232425

I

AC

I

L

V

REF

560k

100nF
100nF

10 F

47nF

24V

Grl/Grs = 20 log

100 F

V

AC

47 F

Ω

10 F

100 F

47Ω

10 F

V

ear

V

12

C2

4.7nF

620

V

Ω

CC

3.9kΩ

23

8

RMC

REF

MC

RING

V

CC

DCL

RECIN

DATA

AGC

4

1

SOFT

26

V

28

DTMF

27

V

13

V

17

BUZ

18

V

TEA7088A

1.6kΩ

Sidetone

15kΩ

100nF

L

V

GTR

GREC

SN

7

14

15k

16

EAR+

300

F

2.2

15

EAR-

6

MIC2

2kΩ

Vm

470nF

5

MIC1

10

IVLS

RESET

GND

9

1.6k

Sidetone

Ω

1N4148

I

47 F

LS

15k

Ω

100nF

L

GTR

GREC

SN

7

14

15k

16

EAR+

300

2.2 F

15

EAR-

MIC2

2k

Ω

6

470nF

5

MIC1

1N4148

IVLS

RESET

10

GND

9

I

47 F

LS

1.3k

10k

1.3k

10k

TEA7088A

V

CC

V

REF

Ω

Ω

Ω

V

Ω

ear

V

CC

7088A-14.EPS

V

CC

V

REF

Ω

Ω

Ω

V

ear

Ω

V

CC

7088A-15.EPS

13/17

TEA7088A

Figure 15 : Test 5a(V

47 F

V

REF

560k

Ω

100nF
100nF

10 F

V

47nF

bout

thri

24VV

thri

10 F

100 F

10 F

)

33

Ω

Sidetone

Ω

15k

Ω

SN

7

GTR

14

GREC

15k

16

EAR+

300

2.2 F

15

EAR-

2k

Ω

6

MIC2

470nF

5

MIC1

1N4148

10

IVLS

GND

47 F

1.3k

10k

Ω

V

CC

V

REF

Ω

Ω

Ω

V

CC

47

C2

4.7nF

Ω

620

V

3.9k

Ω

CC

Ω

8

23

4

AGC

1

SOFT

26

V

28

DTMF

27

V

13

VMC

17

BUZ

18

V

RMC

REF

RING

V

CC

DCL

RECIN

DATA

13V

82k

1 F

11 12

S

V

TEA7088A

MSK

OSCRIPON

1.6k

Ω

100nF

L

V

RESET

9

19202122232425

Figure16 : Test 5b(V

V

REF

560k

100nF
100nF

10 F

47nF

V

bout

I

RING

bout

47 F

Ω

)

10 F

100 F

10 F

C2

4.7nF

620

V

Ω

CC

3.9kΩ

8

RMC

REF

MC

RING

V

CC

DCL

4

AGC

1

SOFT

26

V

28

DTMF

27

V

13

V

47

Ω

17

BUZ

18

V

33

Ω

13V

1 F

82k

1.6k

Ω

Side tone

15k

Ω

Ω

V

CC

100nF

23

RECIN

TEA7088A

11 12

S

V

15k

300

1.3k

10k

V

REF

Ω

Ω

Ω

Ω

L

V

GTR

GREC

EAR+

SN

7

14

16

2.2 F

15

EAR-

MIC2

2k

Ω

6

470nF

5

MIC1

1N4148

DATA

MSK

OSCRIPON

10

IVLS

RESET

GND

19202122232425

9

I

LS

47 F

V

CC

7088A-16.EPS

14/17

6 bitserialcode (0111XX/Fi/010001) ; OSCIN = 1.79MHzexternal clock (default mode)
or 3.58MHz external cera mic/crystal (with code ”101000”to select internal oscillator)

7088A-17.EPS

Figure17 : Test 6(DTMF)

100 F

600

560k

100nF
100nF

10 F

47nF

Ω

47 F

Ω

100 F

I

L

V

REF

10 F

47

10 F

C2

4.7nF

Ω

620

V

3.9k

Ω

CC

Ω

23

8

RMC

REF

MC

RING

V

CC

DCL

RECIN

DATA

4

AGC

1

SOFT

26

V

28

DTMF

27

V

13

V

17

BUZ

18

V

33

13V

82kΩ

1 F

11 12

S

V

TEA7088A

MSK

OSCRIPON

TEA7088A

Ω

Side tone

1.6kΩ

100nF

L

V

GTR

GREC

EAR+

EAR-

MIC2

MIC1

IVLS

RESET

GND

19202122232425

9

15kΩ

SN

7

14

16

15k

300

1.3k

10k

V

CC

V

REF

Ω

Ω

Ω

Ω

2.2 F

15

2k

Ω

6

470nF

5

1N4148

47 F

V

CC

10

I

LS

6 bitserial code (00XXXX/Fi/010010) ; OSCIN= 1.79MHzexternal clock (defaultmode)
or 3.58MHz external cera mic/crystal (with co de ”101000” to select internal oscillator)

7088A-18.EPS

15/17

TEA7088A

TYPICALAPPLICATION

R6

C5

R5

Sidetone

R13 300Ω

R11 33Ω

R12 82kΩ

D2 13V

R10

Impedance

CC

V

REF

V

R8 1.3kΩ

R14 10kΩ

C17

2.2nF

Handset

CC

V

C26 1µF

C22 47nF

C21 47nF

C30

10

IVLS

RING

V

18

47nF

3.58MHz

OSC

GND
RESET
PON

X2

9

192021 2223242526

RI
MSK
DATA
DCL

RMC

V

R17

15kΩ

7

14

SN

GTR

V

RECIN

SOFT

1

GREC

DTMF

28

C12

100nF

L

V

S

V

11 12

1µF

C11

23

CC

8

620Ω

AGC

4

16

EAR+

TEA7088A

REF

VMCV

13

27

15

EAR-

R21

2kΩ

6

MIC2

5

MIC1

BUZ

17

123S

MCU

*0#R

456M

789L

Q1 BSS92

C2

4.7nF

R27

5.6Ω

V

Ω

R28 22k

C18

30pF

C19

X1

30pF

R25

C8

47µF

CC

REF

V

C3 100nF

R4 560kΩ

C13 100nF

C10

C14

470µF

47nF

47Ω

Buzzer

C16

D3

10µF

24V

C15 4.7µF

R2

330kΩ

D5 BAT42

R15 1kΩ

Q3

R29

22kΩ

BF393

D11 6.2V

D8D9

R40 1kΩ

SW1A

D7D6

SW1B

4 x 1N4004

C1 820nF

A

B

7088A-19.EPS

16/17

PACKAGE MECHANICAL DATA

28 PINS - PLASTICPACKAGE

TEA7088A

Dimensions

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

Millimeters Inches

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 45

o

(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

S8

Informationfurnishedis believedto be accurateand reliable.However, SGS-THOMSON Microelectronics assumesno responsibility
for the consequences of use of such information nor for any infringementof patents or other rights of third parties whichmay result
from its use. No licence is granted by implication orotherwise underany patentor patent rights of SGS-THOMSONMicroelectronics.
Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all
informationpreviouslysupplied.SGS-THOMSON Microelectronics products arenot authorized for use as critical components in life
support devices or systemswithout express written approval of SGS-THOMSON Microelectronics.

 1998 SGS-THOMSON Microelectronics - All Rights Reserved

2

Purchase of I

2

I

C Patent. Rights to use these components in a I2C system,is granted provided that the system conforms to

Australia - Brazil - Canada - China- France - Germany - Italy - Japan - Korea - Malaysia - Malta - Morocco

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

C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips

2

C Standard Specifications as defined by Philips.

the I

SGS-THOMSON Microelectronics GROUP OF COMPANIES

o

(Max.)

PM-SO28.EPS

SO2 8.TB L

17/17