STMICROELECTRONICS TEA7088AFP

TEA7088A
LOW-RANGE PHONE DEDICATED CHIP
.
.
.
..
.
RING
- GENERATION OF 8 MELODY TONES
(Including the 3 German Melody Tones)
- 4 STEPS DIGITAL CONTROL ON THE AMPLIFIER OUTPUT LEVEL
SPEECH
- TRANSMIT GAINEXTERNALLY ADJUSTABLE
- RECEIVINGGAINEXTERNALLYADJUSTABLE
- AGCSLOPEEXTERNALLYPROGRAMMABLE
- SOFTCLIPPING ON 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 SERIAL
BUS INTERFACE
MICROCONTROLLER INTERFACE
- 1.79MHz CLOCK OR 3.58MHz OSCILLATOR
INPUT
MICROCONTROLLER POWER SUPPLY
MICROCONTROLLER CONTROL INTERFACE INCLUDING SERIAL BUS
LINE CURRENT EXTRACTOR FOR SUPPLY
OF EXTERNAL PERIPHERALS
DESCRIPTION
The TEA7088A is a Telephone Analog Front End
device, TAFE, which integrates the three basic
functions of a standard telephone set :
- Speech network,
- DTMF generator,
- Ringer generator on buzzer.
A complete telephone set can be designed using
TEA7088A associated with a low cost microcontroller.
January 1998
SO28
(Plastic Package)
ORDER CODE : TEA7088AFP
PIN CONNECTIONS
S OFT
1
28
DTMF
RECIN
2
27
VREF
SN
3
26
VRMC
AGC
4
25
DCL
MIC1
5
24
DATA
MIC2
6
23
MSK
GTR
7
22
OSC
VCC
8
21
RI
GND
9
20
P ON
IVLS
10
19
RES
VS
11
18
VRING
VL
12
17
BUZ
VMC
13
16
EAR+
GREC
14
15
EAR-
7088A-01.EPS
.
1/17
TEA7088A
SPEECH
The speech network includes :
- a low noise transmit channel suitable for any kind
of microphone transducer. Softclipping on transmit line signal is provided by the chip.
- a low noise receive channel with symmetrical
outputs to be compatible with both piezoceramic
and electrodynamic earpiece. An additional 6dB
gain can be inserted in the receive channel
through software control.
- a line length gain control (AGC) with starting point
of gain regulation fixed at 25mAline current ; slope
of gain regulationis externallyadjustablewith one
resistor.AGC can be removedby hardware (maximum 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 CEPT
requirements with an external single pole filter.
RINGER
Up to 8 different tones can be generated by the
TEA7088Aringer. The digital volume control of the
ringer can be performed through a specific command (4 steps). A ring indication signal is provided
to the microcontroller by the TEA7088A.If more
tones are requested the input RM/MSK allows to
inject tones generated by the microcontroller.
FURTHER ADVANTAGES
The microcontroller power supply is provided by the
TEA7088A.The power supply is specifically designed
to copewitha longflash or a long groundkey duration.
The TEA7088A is able to supply the necessary
current to an external speakerphone circuit
TEA7540 and loudspea ker amplifier TEA7532
without any additional circuitry.
Line current and reset indications are provided to
the microcontroller by the TEA7088A.
The microcontroller drives the TEA7088A through
a 2 wires serial interface.
Name
SOFT
RECIN
SN
AGC
MIC1
MIC2
GTR
VCC
GND
IVLS
VS
VL
V MC
GREC
EAREAR+
BUZ
VRING
RES
PON
RI
OSC
MSK
DATA
DCL
VRMC
VREF
DTMF
2/17
Pin N°
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Description
Transmit Softclipping Time Constant
Receiving Input
Sidetone Network Input
Line Current Regulation Stop Value
Microphone Input
Microphone Input
Transmit Gain Adjustment
Transmit and Receive Part Power Supply
Ground
Line Current Source Power Supply
Voltage Stabilizer
Positive Line
Unregulated Microcontroller Power Supply
Receive Gain Adjustment
Negative Earphone Output
Positive Earphone Output
Ringer Buzzer Output
Ring Power Supply
Reset
Power On
Ring Indicator
Oscillator Input
Mask, Ring Melody Input
Data Input
Data Clock Input
Microcontroller Stabilized Power Supply
Reference Voltage (VCC/2)
DTMF Filter
7088A-01.TBL
PIN DESCRIPTION
7088A-02.EPS
C14
R17
R14
R12
C3
R8
R4
C3
Microphone
C11
R11
Ea rphone
To Line
MIC2
MIC1
GTR
SOFT
EAR-
EAR+
GREC
VREF
VS
R10
6
5
7
1
15
16
14
27
11
VCC
VIN
R25
-1
Earphone
Amplifier
VREF
12
4
AGC
AGC
KVL
VSTAB
VL
VCC
DTMF
28
8
C8
MUTE
R13
9
GND
AGC
SIDETONE
& AGC
VREF
2
3
SN
20
To P
RES
19
PON & RESET
CONTROL
PON
VCC
21
RI
To P
22
OSC
OSCILLATOR
P
INTERFACE
DTMF
GENERATOR
RING
GENERATOR
MUTE
CONTROL
1.79MHz
EXT. CLOCK
/2
TEA7088A
BUZZER
AMPLIFIER
RING POWER
SUPPLY
3.58MHz
RESONATOR
LOGIC POWER
SUPPLY
C12
SERIAL
REGULATOR
RECIN
LINE CURRENT
POWER SUPPLY
10
IVLS
C30
Sidetone
VMC
BUZ
VRING
VRMC
24 DATA
25 DCL
23 MSK
13
17
26
18
To P
C10
C15
C16
R40 + R15
C1
To Line
TEA7088A
Figure 1 : Block Diagram
3/17
TEA7088A
ELECTRICAL CHARACTERISTICS
The block diagram is given in Figure 1.
The values of the different networks used in this datasheet are defined as followed :
- The return loss is adjusted by R10 of 600Ω.
- The transmit adjust gain network R8 is calculated in 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 600Ω load on line.
- The DC characteristics are set by a resistor of 82kΩ between VL and VS.
Symbol
Parameter
Authorized Voltage on
Pin 2 - RECIN
Pin 3 - SN
Pin 8 - VCC
Pin 10 - IVLS
Pin 12 - VL
Pin 13 - VMC
Pin 17 - BUZ
Pin 18 - VRING
Pin 19 - RES
Pin 20 - PON
Pin 21 - RI
Pin 22 - OSC
Pin 23 - MSK
Pin 24 - DATA
Pin 25 - DCL
Pin 26 - VRMC
Value
Unit
13
12
11
6
12
6
VRING +0.3, GND -0.3
27
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
VRMC +0.3, GND -0.3
5
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
120
mA
ILINE
Line Current
IRING
Ring Current
50
mA
Toper
Operating Temperature
-25, +70
°C
Tstg
Storage Temperature
-55, +150
°C
Tj
Junction Temperature
-25, +150
°C
DC Characteristics (Tamb = 25°C ; Logic in Default Mode unless otherwise noted)
Symbol
VL
Parameter
Line Voltage
- In Speech and DTMF Mode
- In Mask Mode
Test Conditions
Test 1
IL = 22mA
IL = 90mA
IL = 22mA
Min.
Typ.
Max.
Unit
4
6.7
4.6
7.5
5.2
8.3
3
V
V
V
IVRMC
Stabilized Supply Voltage
- Output Current
VRMC
- Output Voltage
IRMC = 1.5mA
3.15
3.35
IVMC
Unstabilized Supply Voltage
- Start up Current
- Output Current
Test 1, IL = 22mA
VMC = 2.5V, IVRMC = 1.5mA
VMC = 3.6V, IVRMC = 0mA
10
15
3
Line Current Source Supply
Test 1, VLS = 0V ; VMC = 3.6V
IL = 22mA
IL = 90mA
10
67
14
75
ILS
Test 1, IL = 22mA
1.5
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
4/17
mA
3.55
V
mA
mA
18
82
mA
mA
7088A-02.TBL
Absolute Maximum Ratings
TEA7088A
ELECTRICAL SPECIFICATIONS (continued)
AC Characteristics (Tamb = 25°C ; RL = 600Ω ; Logic in Default Mode unless otherwise noted)
Symbol
R1
Parameter
Test Conditions
Min.
Typ.
Max.
17
Test 2, IL = 22mA
f = 300/3400Hz, V AC = -10dBV
Return Loss
Unit
dB
Transmit Characteristics
(Tamb = 25°C ; RL = 600Ω ; f = 1kHz ; Logic in Default Mode unless otherwise noted)
Symbol
Gtx
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
Test 3, Vm = -55dBV
R8 = 1.3kΩ, R25 = 3.9kΩ
IL = 22mA
IL = 90mA
45
38
46
40
47
42
dB
dB
Microphone Input Impedance
between MIC1 & MIC2
32
40
48
kΩ
Noise
Test 3, 2kΩ on microphone inputs,
IL = 22mA
Microphone Mute
Test 3, Vm = -55dBV, IL = 22mA
Soft Clipping
- Distortion
- Maximum Level on Line
Test 3, IL = 22mA, see Figure 2
Vm = -41dBV
Vm = -34dBV
Microphone Gain
Gtxl
Gtxs
Zmic
Ntx
Mmic
Dtx
VL Max.
Figure 2 : Softclipping
-10
R25 (Ω) =
-5
-2
1
10
Vmicrophon e pe a k (mV)
100
7088A-03.EPS
VAC peak on line (V)
-15
1
Figure 3
8
4
VAC pe a k
20
40
60
IL (mA)
80
10 0
7088A-04.EPS
VL (Pin 12) (V)
2
1.5
%
Vp
300
ISL − 5mA
(R25 > 2.6kΩ)
For line current lower than ILL or higher than ISL,
The transmit and receive gains have a constant
value.
AGC can be inhibited also through MCU code
”010100”. In this case Tx and Rx gains are fixed
2dB lower than the maximum gain.
VAC pe a k
6
0
0
dB
If no resistor or a resistor higher than 300kΩ is
connected on Pin AGC, the gain is constant and
equal to Gtxl and Grxl. ±0.5dB.
10
2
60

R10// RL + R11
Gtxl = 20log 820 ⋅

R8 // 50kΩ 

The AGC variation is programmed with one resistor
connected on Pin AGC. ISL is the line current at
which the gain must be decreased by 6dB.
Thres hold
Level
0.1
dBmp
The maximum gain Gtl is adjustable between 44
and 56dB with R8 :
10
0.1
-76
The minimum saturation voltage of the TEA7088A
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
avoid to reach the 2.2V limit on TEA7088A respect
to ground.
5/17
TEA7088A
ELECTRICAL SPECIFICATIONS (continued)
Receive Characteristics (Tamb = 25°C ; RL = 660Ω ; f = 1kHz)
Symbol
Eff
GRXl
GRXs
Dr
Nr
Vear
(010010)
Zout
Parameter
Sidetone
Eff = (Vear+ - Vear -) /Vm
Gain in Symmetric Mode
Grx = (Vear+ - Vear-) / VL
Test Conditions
Test 3, Vm = -55dBV, IL = 22mA,
R14 = 10kΩ, R17 = 15kΩ
Test 6, VL = -14.5dBV, R14 = 10kΩ,
R17 = 15kΩ, R25 = 3.9kΩ
IL = 22mA
IL = 90mA
Test 4, Rear = 300Ω, IL = 22mA
Vear = -12dBV
Vear = -8dBV
Test 4, IL = 22mA
IL = 22mA, VL = -14.5dBV
Distortion
Noise
Earphone Mute
Min.
0.7
-6
Typ.
Max.
22.5
Unit
dB
1.7
-4
2.7
-2
dB
dB
2
5
%
%
dBmp
dB
20
Ω
-76
60
Output Impedance
Automatic Gain Control Inhibition (Tamb = 25°C ; RL = 660Ω ; f = 1kHz no AGC mode selected)
Symbol
Gtp
Grp
Parameter
Test Conditions
Test 3 & Test 4, IL = 22 to 90mA
Code : 010100
Vm = -55dBV
VL = -14.5dBV
Transmit Gain
Receive Gain
Min.
Typ.
Max.
Unit
Gtxl -3
Grxl -3
Gtxl -2
Grxl -2
Gtxl -1
Grxl -1
dB
dB
Min.
Typ.
Max.
Unit
1
20
9
1.2
V
V
mA
3.75
4.05
100
V
ms
V
13
5.6
2.8
1.4
13.5
6.7
3.4
1.8
VRMS
VRMS
VRMS
VRMS
Ring Characteristics (Tamb = 25°C)
Symbol
VThri ON
VThri OFF
ICRing
VRMC
tRON
VRING
Vbout
Parameter
Ringing Threshold Voltage
Internal Consumption in Ring
Mode
Microprocessor Supply Voltage
Rise Time
Internal Zener Voltage
Buzzer Vout
Freq = 1312Hz
Freq. Code 001111
Test Conditions
Test 5 a/b
RI high (see Figure 4)
Rl low (see Figure 4)
VRING = 10V
15
5
3.45
IRING = 10mA
27
VRING =
Level
Level
Level
Level
27Vzener (see Figure 5)
Code (011111)
Code (011110)
Code (011101)
Code (011100)
Figure 4 : Ringer Hysteresis Ringer
12
4.4
2.2
1
Figure 5 : Ringer Output Waveform
ON
Ringer
Status
Ringer Threshold (VTHRI)
6/17
VON
V
7088A-06.EPS
VOFF
7088A-05.EPS
OFF
Vb o ut
TEA7088A
ELECTRICAL SPECIFICATIONS (continued)
DTMF Generator (Tamb = 25°C ; RL = 660Ω)
Symbol
Parameter
Test Conditions
Min.
Test 6 Pin Osc
fclock = 1.79MHz oscillator off
or
Resonator : 3.58MHz oscillator on
C13 =100nF, IL = 22mA
- 0.4
Amf
Tone Frequency Accuracy
Llf
Lhf
Low Freq. Group Line Level
High Freq. Group Line Level
-10
-8
+1
Pmf
Preemphasis HF/LF
tDON
tDOFF
Rise Time
Decay Time
Cmf
DTMF Confidence Tone :
Earphone level (low freq.)
Earphone level (high freq.)
–
- Unwanted Harmonics Level
(see Figure 6)
Typ.
Max.
Unit
0.4
%
-8.5
-6.5
-7
-5
dBm
dBm
+2
+3
dB
5
5
ms
ms
13
17
17
22
21
27
mV
mV
–
–
–
–
Figure 6 : Unwanted Harmonics Level in DTMF
-30
-70
-90
100
1k
10k
(Hz)
100k
1M
7088A-07.EPS
Vline (dBm)
-50
Figure 7 : Microcontroller Interface
VRING
VL
18
IS pe ech
kIL
VMC
C10
47 F
I (In Ring)
VRMC (3.4V)
26
VREFI
5.6V
C15
10 F
P
+ LCD
7088A-08.EPS
13
Ba tte ry
IS tart-u p
7/17
TEA7088A
MICROCONTROLLER INTERFACE WITH TEA7088A
All inputs can be driven by a Low level max. of
0.1 x VRMC and a high level min. of 0.9 x VRMC .
Inputs MSK, DCL and DATA have internal pull-up
resistors of 120kΩ and input OSC has a internal
pull up of 240kΩ.
All outputs can drive a ±1mA typical.
Power Supply
The microcontroller is power supplied by a 3.4V
regulated supply (VRMC) and by an unregulated
power supply (VMC).
The two supplies are connected through a serial
regulator.The unregulatedpower supply (VMC) has
a DC voltageequal to: V12 - 0.6V and must be lower
than 6V. It is also possible to connect a battery at
Pin VMC and use the regulated output at Pin VRMC
to supply a LCD driver.
The current consumption on the serial regulator
has a typical value of 60µA.
Power ON (PON)
The TEA7088Ageneratesa poweron signal (PON)
as soon as the voltage on Pin VRMC is higher than
2.6V (0.75 x VRMC final) and the line current is present.
Note : Du ri ng th e b re a k p e riod in t he
loopdisconndect and Flash mode and
during the exchange line break, the power
ON signal goes to low level. Maximum delay
for Pon decay edge after I Line goes to zero
is 50ms (with C8 = 47µF, C11 = 1µF,
C27 = 10µF).
Reset
The TEA7088Agenerates a rise edge Reset signal
as soon as the logic power supply is higher than
2.6V (0.75 x VRMC final).
RESET remains high until VRMC decreases below
2.5V or the RESET control code is received. In
Ring, RESET is identical to RI output.
Only new positive edge PON, derived on opening
and closing the line, is forcing the default mode
again. The Reset control code is only active in
speech mode.
8/17
Serial Bus Interface (Data and Clock)
The serial bus uses 6 bits. Astandard 8 bit bus can
be used, bits a6 and a7 are not take in account by
the 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/Microphone mute
c) The Data Codes (DTMF, ring frequencies) :
Those data codes are stored inside the
TEA7088Aand are used as soon as the dialing
code 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-Flop”
codes.
For instance : The first time that the+6dB code
is sent, the receive gain increases of +6dB.
If the same code is sent again, the receive gain
goes back to normal value. In the same way the
3.58MHz internal oscillator can be switched
OFF with a second transmission of the proper
code.
e) The RESET Code :
Reset code from the MCU will reset internallogic
of TEA7088A to default mode and will induce
TEA7088A to generate a ”RESET” status ”low”
to the MCU on Pin 19.
Warning : the ”RESET” code deactivates the
serial bus interface which is reactivated only
after a ”ON-HOOK/OFF-HOOK” sequence.
f) The INITIALIZATION Code :
Initialization code from the MCU will reset the
internal logic of TEA7088A to default mode, but
the TEA7088Awill not generatereset command
to the MCU on Pin 19.
TEA7088A
MICROCONTROLLER INTERFACE WITH TEA7088A (continued)
Figure 8 : Reset and Power ON
Wit ho u t u s ing th e RES ET Co d e th ro u gh th e S e ria l Bu s Inte rfa c e
IL
A
B
C
D
E
D
A
VMC
5
2.7
t
VRMC
3.4
2.6
t
2.5V
t
PON
t
RES ET
t
Us in g the RES ET Cod e th ro u gh th e S e ria l Bus Inte rfa c e
IL
A
B
C
D
E
D
F
D
A
VMC
5
2.7
t
VRMC
3.4
2.6
t
2.5V
PON
td
td
t
t
RES ET
t
Re s et control code (010111)
s e nt on the s e rial bus
7088A-09.EPS
A : ON-HOOK
B : S TART UP + S P EECH
C : P ULSE DIALING
D : SP EECH or DTMF
E : LINE BREAK EXCHANGE DURATION
F : LINE BREAK EXCHANGE DURATION > td
td : DELAY FIXED BY THE MICROCONTROLLER
9/17
TEA7088A
MICROCONTROLLER INTERFACE WITH TEA7088A (continued)
The Start Up Conditions of the TEA7088A
As soon as RESET is high and before sending any
code the circuit is in the following default configuration :
- 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, introducing a Mute or speech code implies to wait 1ms to
end the sinewave or square period.
DTMF Dialing
To dial in DTMF the following sequence of codes
must be sent :
DTMF Frequency code : 00XXXX
Dialing Mode code
: 010001
Mute or SPEECH code : 010010 or 010000
The duration of the DTMF signal is fixed by the
delay between Dialing mode code and MUTE or
SPEECH 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 code
0010101. To recover the normal speech voltage at
the end of dialing the mask code must be sent
again.
If the mask code is not used the voltage over the
TEA7088Aduring dialing is the same as in speech
mode.
Ring Indicator (RI)
In ring mode TEA7088A generates a high logic
level on Pin RI as soon as the voltage on Pin VRING
is higher than VTHRI ON (19V Typ.), and the voltage
on VRMC is higher than 3.4V.
When the voltage on VRMC becomes higher than
2.6V, RESET signal becomes also high.
Mask Input (MSK)
MSK input must be high by default (Figure 10).
In speech configuration forcing MSK input to low
level will have same functionality than the MASK
code.
For ring mode when it is necessary to send other
frequencies than the 8 basic ones, this input allows
to drive the buzzer output.
Figure 9 : DATA/CLOCK Timing
t0 t1
t2
t3 t4
t5
t3
CLK Data
S ynchro
a1
a2
a3
a4
Datas with a Change During CLK = 1
a5
a6
t0, t1, t2, t3, t4, t5 > 1µs
7088A-10.EPS
a0
Data
Figure 10 : MASK Timing
P ULSE MODE
OTHER MODES
FLASH MODE
OTHER MODES
MSK
10/17
7088A-11.EPS
IL
TEA7088A
MICROCONTROLLER INTERFACE WITH TEA7088A (continued)
Keyboard
Remarks
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
0
0
0
0
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
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
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
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
822Hz Ring Signal
744Hz Ring Signal
1005Hz Ring Signal
909Hz Ring Signal
1187Hz Ring Signal
1074Hz Ring Signal
1451Hz Ring Signal
1312Hz Ring Signal
0
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
Speech Mode
Dialing Mode or Ring Start
Earphone & Microphone Mute
Microphone Mute
0
1
0
1
0
1
Mask/No Mask
0
1
0
1
1
0
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)
”2”
”1”
”A”
”3”
”8”
”7”
”C”
”9”
”5”
”4”
”B”
”6”
”0”
”*”
”D”
”#”
”+6dB”
1336Hz
1209Hz
1633Hz
1477Hz
1336Hz
1209Hz
1633Hz
1477Hz
1336Hz
1209Hz
1633Hz
1477Hz
1336Hz
1209Hz
1633Hz
1477Hz
+ 697Hz
+ 697Hz
+ 697Hz
+ 697Hz
+ 852Hz
+ 852Hz
+ 852Hz
+ 852Hz
+ 770Hz
+ 770Hz
+ 770Hz
+ 770Hz
+ 941Hz
+ 941Hz
+ 941Hz
+ 941Hz
In DTMF
Dialing
In Ring
Mode
Normal/+6dB on Receive Channel
7088A-03.TBL
Codes
a5
11/17
TEA7088A
Figure 11 : Test Circuits - Test 1 (VL / VRMC / VMC / IVMC / ILS )
33Ω
47 F
82kΩ
1 F
100nF
2
11
VS
560kΩ
8
RECIN
4 AGC
VCC
3.9kΩ
VREF
1 S OFT
12
3
VREF
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
S idetone
15kΩ
1.6kΩ
VCC
VCC
600Ω
IL
13V
620Ω
SN
C2
4.7nF
VL
100 F
GREC 14
10 F
100nF
15kΩ
28 DTMF
EAR+ 16
27 VREF
TEA7088A
13 VMC
10 F
300Ω
2.2 F
100 F
EAR- 15
2kΩ
MIC2 6
47Ω
17 BUZ
470nF
MIC1 5
24
23
22
20
19
GND
RESET
PON
RI
21
1N4148
IVLS 10
VCC
ILS
9
7088A-12.EPS
25
OSC
10 F
MSK
DCL
18 VRING
24V
DATA
47nF
47 F
Figure 12 : Test 2 (R1)
33Ω
IAC
13V
VCC
VCC
47 F
1 F
100nF
4 AGC
560kΩ
8
2
11
VS
VRE F
RECIN
3.9kΩ
1 S OFT
12
3
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
VREF
SN
VAC
S ide tone
15kΩ
1.6kΩ
82kΩ
620Ω
VCC
IL
C2
4.7nF
VL
100 F
GREC 14
10 F
15kΩ
100nF
28 DTMF
EAR+ 16
27 VREF
TEA7088A
13 VMC
10 F
300Ω
2.2 F
100 F
EAR- 15
2kΩ
47Ω
MIC2 6
17 BUZ
470nF
47nF
12/17
IAC
RI = 20 log
Z + 600
Z - 600
RI
PON
RESET
GND
25
24
23
22
21
20
19
9
1N4148
IVLS 10
VCC
ILS
47 F
7088A-13.EPS
VAC
Z=
OSC
10 F
MSK
24V
DATA
18 VRING
DCL
MIC1 5
TEA7088A
Figure 13 : Test 3 (Gtl / Gts / Zmic / Nt / Mmic / Dt / Vlmax / Eff)
33Ω
C2
4.7nF
47 F
82kΩ
1 F
100nF
11
1 S OFT
12
3
VL
2
VS
560kΩ
8
VCC
4 AGC
RECIN
3.9kΩ
VR EF
VREF
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
S ide tone
15kΩ
1.6kΩ
VC C
VCC
600Ω
IL
13V
620Ω
SN
100 F
GREC 14
10 F
15kΩ
100nF
28 DTMF
EAR+ 16
27 VREF
TE A7088A
13 VMC
100 F
10 F
Ve a r
300Ω
2.2 F
EAR- 15
MIC2 6
47Ω
17 BUZ
2kΩ
47nF
470nF
24
22
21
20
19
GND
PON
RI
OSC
23
MIC1 5
1N4148
IVLS 10
VC C
ILS
9
47 F
7088A-14.EPS
25
V12 (010000)
Mmic = 20 log
V12 (010011)
V12
Gtl/Gts = 20 log
Vm
MSK
DCL
DATA
10 F
RESET
18 VRING
24V
Vm
Ve a r
Eff = 20 log
Vm
Figure 14 : Test 4 (Grl / Grs / Dr / Mear / Nr)
33Ω
IAC
C2
4.7nF
47 F
1 F
100nF
11
VS
1 SOFT
3
12
VL
2
VCC
560kΩ
8
RECIN
4 AGC
Sidetone
15kΩ
1.6kΩ
3.9kΩ
VREF
100nF
82kΩ
VCC
VCC
VAC
IL
13V
620Ω
VREF
SN
100 F
1.3kΩ
GTR 7
10kΩ
26 VRMC
GREC 14
10 F
100nF
15kΩ
28 DTMF
EAR+ 16
27 VREF
TEA7088A
13 VMC
10 F
300Ω
Vear
2.2 F
100 F
EAR- 15
2kΩ
MIC2 6
47Ω
17 BUZ
470nF
MIC1 5
Grl/Grs = 20 log
24
23
22
20
19
GND
RESET
PON
RI
21
9
1N4148
IVLS 10
VCC
ILS
47 F
7088A-15.EPS
25
OSC
10 F
MSK
24V
DATA
18 VRING
DCL
47nF
Vear
V12
13/17
TEA7088A
Figure 15 : Test 5a (Vthri)
33Ω
C2
4.7nF
13V
1 F
100nF
1 S OFT
12
3
VR EF
SN
11
VL
2
VS
56 0kΩ
8
RECIN
4 AGC
VCC
3.9kΩ
VRE F
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
S ide tone
15kΩ
1.6kΩ
VC C
VCC
47 F
82kΩ
62 0Ω
GREC 14
10 F
100nF
15kΩ
28 DTMF
EAR+ 16
27 VRE F
TEA7088A
13 VMC
10 F
300Ω
2.2 F
100 F
EAR- 15
2kΩ
MIC2 6
47Ω
17 BUZ
470nF
47nF
PON
RESET
25
24
23
22
21
20
19
1N4148
GND
RI
10 F
OSC
24V
MSK
Vthri
DATA
18 VRING
DCL
MIC1 5
IVLS 10
VC C
7088A-16.EPS
Vb o ut
47 F
9
Figure 16 : Test 5b (Vbout)
33Ω
13V
1 F
100nF
11
1 S OFT
12
3
VL
2
VS
560kΩ
8
RECIN
4 AGC
VCC
3.9kΩ
VREF
VREF
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
Sidetone
15kΩ
1.6kΩ
VCC
VCC
47 F
82kΩ
620 Ω
SN
C2
4.7nF
GREC 14
10 F
100nF
15kΩ
28 DTMF
EAR+ 16
27 VREF
TEA7088A
13 VMC
10 F
300Ω
2.2 F
100 F
EAR- 15
2kΩ
47Ω
MIC2 6
17 BUZ
24
23
21
20
19
GND
RESET
PON
RI
OSC
22
1N4148
IVLS 10
9
6 bit s e rial code (0111XX/Fi/010001) ; OSCIN = 1.79MHz e xterna l clock (de fa ult mode )
or 3.58MHz e xterna l ceramic/crystal (with code ”101000” to s e lect internal os cillator)
14/17
VCC
ILS
47 F
7088A-17.EPS
25
MSK
10 F
DATA
18 VRING
IRING
470nF
MIC1 5
47nF
DCL
Vbout
TEA7088A
Figure 17 : Test 6 (DTMF)
33Ω
600Ω
1 F
100nF
560kΩ
8
2
11
VS
4 AGC
VCC
3.9kΩ
VREF
1 SOFT
12
3
VREF
1.3kΩ
GTR 7
10kΩ
26 VRMC
100nF
Sidetone
15kΩ
1.6kΩ
VCC
VCC
47 F
82kΩ
RECIN
IL
13V
620Ω
SN
C2
4.7nF
VL
100 F
GREC 14
10 F
100nF
15kΩ
28 DTMF
EAR+ 16
27 VREF
TEA7088A
13 VMC
10 F
300 Ω
2.2 F
100 F
EAR- 15
2kΩ
MIC2 6
47Ω
17 BUZ
470nF
MIC1 5
24
23
21
20
19
GND
RESET
PON
RI
OSC
22
1N4148
VCC
IVLS 10
9
ILS
47 F
7088A-18.EPS
25
MSK
10 F
DATA
18 VRING
DCL
47nF
6 bit s e rial code (00XXXX/Fi/010010) ; OSCIN = 1.79MHz e xterna l clock (de fault mode )
or 3.5 8MHz e xterna l ce ramic/crystal (with code ”101 000” to s e lect interna l o s cillator)
15/17
7088A-19.EPS
B
A
D8
D6
SW1B
D7
4 x 1N4004
D9
SW1A
C1 820nF R40 1kΩ
Q3
BF393
R29
22kΩ
D11 6.2V
R28 22kΩ
C8
47µF
C19
30pF
D5 BAT42
R2
330kΩ
D3
24V
R15 1kΩ
Buzzer
C14
47nF
C13 100nF
C3 100nF
R4 560kΩ
VREF
VCC
X1
C18
30pF
1 SOFT
4 AGC
25
2
8
26
18 VRING
17 BUZ
13 VMC
27 VREF
28 DTMF
C15 4.7µF
C16
10µF
47Ω
C10
470µF
R25
R10
620Ω
VRMC
V CC
24
DATA
C2
4.7nF
MSK
23
C11
1µF
11
TEA7088A
20
MCU
21
RI
RECIN
DCL
VS
PON
R27
5.6Ω
19
9
22
3
3.58MHz
X2
IVLS 10
MIC1 5
MIC2 6
EAR- 15
EAR+ 16
GREC 14
1
4
7
*
C17
2.2nF
3
6
9
#
S
M
L
R
V CC
C22 47nF
2
5
8
0
R8 1.3kΩ
VREF
VCC
C26 1µF R14 10kΩ
R6
C5
C21 47nF
C30
47nF
R21
2kΩ
R17
15kΩ
R5
Sidetone
GTR 7
C12
100nF
R13 300Ω
12
GND
D2 13V
R12 82kΩ
VL
R11 33Ω
OSC
Impedance
RESET
SN
16/17
Handset
Q1 BSS92
TEA7088A
TYPICAL APPLICATION
TEA7088A
PM-SO28.EPS
PACKAGE MECHANICAL DATA
28 PINS - PLASTIC PACKAGE
Dimensions
Millimeters
Typ.
0.1
0.35
0.23
Max.
2.65
0.3
0.49
0.32
Min.
Inches
Typ.
0.004
0.014
0.009
0.5
Max.
0.104
0.012
0.019
0.013
0.020
o
45 (Typ.)
17.7
10
18.1
10.65
0.697
0.394
1.27
16.51
7.4
0.4
0.713
0.419
0.050
0.65
7.6
1.27
0.291
0.016
0.299
0.050
SO28.TBL
A
a1
b
b1
C
c1
D
E
e
e3
F
L
S
Min.
o
8 (Max.)
Information furni shed is believed to be accurate and reliable. However, SGS-THOMSON Micr oelectronics assumes no responsibility
for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result
from its use. No licence is granted by implication or otherwise und erany patent or patent rights of SGS-THOMSON Microelectronics.
Specifications mentioned in this publication are subject to change without notice. This pu blication supersedes and replaces all
information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life
support devices or systems without express written approval of SGS-THOMSON Microelectronics.
 1998 SGS-THOMSON Microelectronics - All Rights Reserved
Purchase of I 2C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips
2
2
I C Patent. Rights to use these components in a I C system, is granted provided that the system conforms to
the I2C Standard Specifications as defined by Philips.
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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17/17