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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)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
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)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
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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ELECTRICAL SPECIFICATIONS (continued)
Receive Characteristics (Tamb = 25C ; RL = 660 ; f = 1kHz)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
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
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ELECTRICAL SPECIFICATIONS (continued)
DTMF Generator (Tamb = 25C ; RL = 660)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
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.
MICROCONTROLLER INTERFACE WITH TEA7088A (continued)
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
MICROCONTROLLER INTERFACE WITH TEA7088A (continued)
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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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)
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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)
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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 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)
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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
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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
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