Product specification
Supersedes data of 1999 May 20
File under Integrated Circuits, IC03
1999 Oct 14
Page 2
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
FEATURES
Line interface
• Low DC line voltage
• Voltage regulator with adjustable DC voltage
• Symmetrical high impedance inputs (70 kΩ) for
dynamic, magnetic or electret microphones
• DTMF input with confidence tone on earphone and/or
loudspeaker
• Receive amplifier for dynamic, magnetic or
piezo-electric earpieces(with externally adjustable gain)
• Automatic Gain Control (AGC) for true line loss
compensation.
Supplies
• Provides a strong 3.35 V regulated supply for
microcontrollers or diallers
• Provides filtered power supply, optimized according to
line current
• Filtered 2.0 V power supply output for electret
microphone
• PD logic input for power-down.
Handsfree
• Asymmetrical high input impedance for electret
microphone
• Loudspeaker amplifier with single-ended rail-to-rail
output and externally adjustable gain
• Dynamic limiter on loudspeaker amplifier to prevent
distortion
• Logarithmic volume controlon loudspeakeramplifier via
linear potentiometer
• Duplex controller consisting of:
– Signal and noise envelope monitors for both
channels (with adjustable sensitivities and timing)
– Decision logic (with adjustable switch-over and Idle
mode timing)
– Voice switch control (with adjustable switching range
and constant sum of gain during switching).
APPLICATIONS
• Line powered telephone sets.
GENERAL DESCRIPTION
The TEA1098 is an analog bipolar circuit dedicated to
telephonyapplications. It includesa line interface,handset
(HS) microphone and earpiece amplifiers, handsfree (HF)
microphone and loudspeaker amplifiers and a duplex
controller with signal and noise monitors on both channels.
This IC provides a 3.35 V supply for a microcontroller or
dialler and a 2.0 V filtered voltage supply for an electret
microphone.
ORDERING INFORMATION
TYPE
NUMBER
TEA1098TVVSO40plastic very small outline package; 40 leadsSOT158-1
TEA1098HQFP44plastic quad flat package; 44 leads (lead length 1.3 mm);
TEA1098UH−bare die; on foil−
1999 Oct 142
NAMEDESCRIPTIONVERSION
body 10 × 10 × 1.75 mm
PACKAGE
SOT307-2
Page 3
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
QUICK REFERENCE DATA
I
= 15 mA; R
line
TEA1098UH; AGC pin connected to LN;
unless otherwise specified.
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX. UNIT
I
line
V
SLPE
V
BB
V
DD
I
BB
I
BB(pd)
G
v(MIC-LN)
G
v(IR-RECO)
∆G
v(QR)
G
v(TXIN-TXOUT)
G
v(HFTX-LN)
G
v(HFRX-LSAO
SWRAswitching range−40−dB
∆SWRAswitching range adjustmentwith R
∆G
v(trx)
SLPE
=20Ω; Z
= 600 Ω; f = 1 kHz; T
line
=25°C for TEA1098H and TEA1098TV; Tj=25°C for
amb
PD = HIGH; HFC = LOW; MUTE = HIGH; measured according to test circuits;
line current operating rangenormal operation11−130mA
with reduced performance1−11mA
stabilized voltage between SLPE
and GND
regulated supply voltage for
internal circuitry
regulated supply voltage on pin
V
DD
current available on pin V
BB
I
= 15 mA3.43.74.0V
line
I
= 70 mA5.76.16.5V
line
I
= 15 mA2.753.03.25V
line
I
= 70 mA4.95.35.7V
line
VBB> 3.35 V + 0.25 V (typ.)3.13.353.6V
otherwise−V
− 0.25 −V
BB
in speech mode−11−mA
in handsfree mode−9−mA
current consumption on V
BB
PD = LOW−460−µA
during power-down phase
voltage gain from pin MIC+/MIC−
V
= 5 mV (RMS)43.344.345.3dB
MIC
to LN
voltage gain from pin IR
VIR= 8 mV (RMS)28.729.730.7dB
(referenced to LN) to RECO
gain voltage range between pins
−3−+15dB
RECO and QR
voltage gain from pin TXIN to
TXOUT
voltage gain from pin HFTX to LN V
) voltage gain from pin HFRX
to LSAO
V
= 3 mV (RMS);
TXIN
R
= 30.1 kΩ
GATX
= 15 mV (RMS)33.534.735.9dB
HFTX
V
= 30 mV (RMS);
HFRX
R
GALS
= 255 kΩ; I
referenced to
SWR
=70mA
line
12.715.217.7dB
25.52830.5dB
−40−+12dB
365 kΩ
gain control range for transmitand
I
= 70 mA5.456.457.45dB
line
receive amplifiers affected by the
AGC; with respect to I
=15mA
line
1999 Oct 143
Page 4
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
BLOCK DIAGRAM
REG
SLPE
19
LN 18 (15)
STARTER
LINE CURRENT DETECTION
LOW VOLTAGE BEHAVIOUR
(16)17(14)
R1
SWITCH
SUPPLY
MANAGEMENT
(10) 13
(19) 22
(20) 23
V
BB
V
DD
MICS
AGC
GND
HFTX
DTMF
MIC+
MIC−
TXIN
TSEN
TENV
TNOI
RNOI
RENV
RSEN
GALS
LSAO
21 (18)
16 (13)
39 (36)
35 (32)
34 (31)
33 (30)
31 (28)
8 (4)
7 (3)
6 (2)
9 (5)
11 (7)
10 (6)
14 (11)
15 (12)
AGC
Tail currents for preamps
ATTENUATOR
TX AND RX
ENVELOPE AND NOISE
DETECTORS
BUFFERS
AND
COMPARATORS
TEA1098
DUCO LOGIC
SWT STATUS
POWER-DOWN
CURRENT SOURCES
LOGIC
INPUTS
DECODING
VOICE
SWITCH
VOLUME
CONTROL
(38) 1
(37) 40
(39) 2
(27) 30
(26) 29
(29) 32
(24) 27
(25) 28
(21) 24
(22) 25
(23) 26
(1) 5
PD
HFC
MUTE
GATX
TXOUT
GNDTX
SWT
IDT
STAB
SWR
VOL
HFRX
12 (8)
DLC
RECO
GARX
QR
38 (35)
37 (34)
36 (33)
DYNAMIC
LIMITER
Pin numbers in parenthesis apply to the TEA1098H. Pin numbers not in parenthesis apply to the TEA1098TV.
Fig.1 Block diagram.
1999 Oct 144
ATTENUATOR
(17) 20
MGL317
IR
Page 5
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
PINNING
SYMBOL
PD13841power-down input (active LOW)
MUTE23942logic input (active LOW)
n.c.34043not connected
n.c.44144not connected
n.c.−4245not connected
n.c.−4346not connected
n.c.−4447not connected
HFRX511receive input for loudspeaker amplifier
TNOI622transmit noise envelope timing adjustment
TENV733transmit signal envelope timing adjustment
TSEN844transmit signal envelope sensitivity adjustment
RNOI955receive noise envelope timing adjustment
RSEN1066receive signal envelope sensitivity adjustment
RENV1177receive signal envelope timing adjustment
DLC1288dynamic limiter capacitor for the loudspeaker amplifier
n.c.−99 and 13not connected
V
BB
GALS141111loudspeaker amplifier gain adjustment
LSAO151212loudspeaker amplifier output
GND161314 and 15ground reference
SLPE171416line current sense
LN181517positive line terminal
REG191618line voltage regulator decoupling
IR201719receive amplifier input
AGC211820automatic gain control/line loss compensation
V
DD
MICS232022microphone supply
STAB242123reference current adjustment
SWR252224switching range adjustment
VOL262325loudspeaker volume adjustment
SWT272426switch-over timing adjustment
IDT282527Idle mode timing adjustment
TXOUT292628HF microphone amplifier output
GATX302729HF microphone amplifier gain adjustment
TXIN312830HF microphone amplifier input
GNDTX322931 to 32ground reference for microphone amplifiers
MIC−333033negative HS microphone amplifier input
MIC+343134positive HS microphone amplifier input
TEA1098TVTEA1098HTEA1098UH
PINPAD
DESCRIPTION
131010stabilized supply for internal circuitry
2219213.35 V regulated voltage supply for microcontrollers
1999 Oct 145
Page 6
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
SYMBOL
DESCRIPTION
TEA1098TVTEA1098HTEA1098UH
DTMF353235dual tone multi-frequency input
QR363336earpiece amplifier output
GARX373437earpiece amplifier gain adjustment
RECO383538receive amplifier output
HFTX393639transmit input for line amplifier
HFC403740logic input
HFC
HFTX
RECO
GARX
QR
DTMF
MIC+
MIC−
GNDTX
TXIN
GATX
TXOUT
IDT
SWT
VOL
SWR
STAB
MICS
V
DD
AGC
Fig.2 Pin configuration (TEA1098TV).
1999 Oct 146
Page 7
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
handbook, full pagewidth
n.c.
44
n.c.
43
n.c.
42
n.c.
41
n.c.
40
MUTE
39
PD
38
HFC
37
HFTX
36
RECO
35
GARX
34
1
HFRX
2
TNOI
3
TENV
4
TSEN
5
RNOI
6
RSEN
RENV
DLC
n.c.
V
BB
GALS
7
8
9
10
11
12
13
GND
LSAO
14
SLPE
TEA1098H
15
LN
Fig.3 Pin configuration (TEA1098H).
FUNCTIONAL DESCRIPTION
All data values given in this chapter are typical, except
when otherwise specified.
Supplies
LINE INTERFACE AND INTERNAL SUPPLY (PINS LN, SLPE,
REG AND VBB)
Thesupply for theTEA1098 and itsperipheralsis obtained
from the line. The IC generates a stabilized reference
voltage (V
) between pins SLPE and GND.
ref
This reference voltage is equal to 3.7 V for line currents
below 18 mA. When the line current rises above 45 mA,
the reference voltage rises linearly to 6.1 V. For line
currents below 9 mA, V
is automatically adjusted to a
ref
lower value. The performance of the TEA1098 in this
so-called low voltage area is limited (see Section “Low
voltage behaviour”). The reference voltage is temperature
compensated.
33
QR
DTMF
32
31
MIC+
30
MIC−
GNDTX
29
28
TXIN
GATX
27
TXOUT
26
IDT
25
24
SWT
VOL
23
21
16
REG
17
18
19
IR
DD
V
AGC
20
MICS
STAB
22
SWR
FCA020
The voltage between pins SLPE and REG is used by the
internal regulator to generate the stabilized reference
voltage and is decoupled by a capacitor connected
between pins LN and REG. This capacitor, converted into
an equivalent inductance realizes the set impedance
conversionfrom its DC value(R
)to its AC value(done
SLPE
by an external impedance).
The IC regulates the line voltage at pin LN which can be
calculated as follows:
V
I
V
LN
SLPEIline
refRSLPEISLPE
×+=
Ix–=
where:
I
= line current.
line
Ix= current consumed on pin LN (approximately a
few µA).
I
= current flowing through the R
SLPE
SLPE
resistor.
1999 Oct 147
Page 8
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
The preferred value for R
is 20 Ω. Changing this value
SLPE
not only affects the DC characteristics, it also influences
the transmit gains to the line, the gain control
characteristic,the sidetonelevel, and themaximum output
swing on the line.
Figure 4 shows that the internal circuit is supplied by pin
VBB, which combined with the line interface is a strong
supply point.
The line current through resistor R
is sunk by the V
SLPE
BB
voltage stabilizer, and is suitable for supplying a
loudspeaker amplifier or any peripheral IC. Voltage VBBis
3.0 V at line currents below 18 mA and rises linearly to
5.3 V when the line current rises above 45 mA. It is
temperature compensated.
handbook, full pagewidth
LN
C
REG
4.7 µF
SLPE
TP1
R3
R
SLPE
20 Ω
J1
The current switch TR1-TR2 is intended to reduce
distortionof large AC linesignals. Current I
SLPE
issupplied
to VBB via TR1 when the voltage on pin SLPE is above
VBB+ 0.25 V. Whenthe voltage on pin SLPE is below this
value, I
Voltage V
is shunted to GND via TR2.
SLPE
can be increased by connecting an external
ref
resistor between pins REG and SLPE. For large line
currents, this increase can slightly affect some dynamic
performances such as maximumsignal level on the line at
2% Total Harmonic Distortion(THD). Theexternal resistor
does not affect the voltage on pin VBB; see Fig.5 for the
main DC voltages.
TR2
GND
D1
E1
TR1
E2
V
BB
REG
GND
R1
R2
from
preamp
TN1
Fig.4 Line interface principle.
D1
TN2
J2
GND
MGM298
1999 Oct 148
Page 9
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
handbook, full pagewidth
8
voltages
(V)
6
4
2
0
00.01
0.020.05
Fig.5 Main DC voltages.
V
SUPPLY FOR MICROCONTROLLERS (PIN V
DD
The voltage on the V
supply point follows the voltage on
DD
DD
)
VBBwith a difference typically of 250 mV, internallylimited
to 3.35 V. This voltage is temperature compensated.
This supply point can provide a current of up to typically
3 mA. Its internal consumption stays low (a few 10 nA) as
long as VDD does not exceed 1.5 V (see Fig.6).
An external voltage can be connected to VDD with limited
extra consumptionon VDD(typically 100 µA).This voltage
source should not be below 3.5 V or above 6 V.
VBBand VDDcan supply current to external circuits within
the line limits, taking into account the internal current
consumption.
UPPLY FOR MICROPHONE (PINS MICS AND GNDTX)
S
The MICS output can be used as a supply for an electret
microphone. Its voltage is equal to 2.0 V; it can source a
current of up to 1 mA and has an output impedance equal
to 200 Ω.
FCA049
LN
SLPE
V
BB
V
DD
MICS
0.040.03
OW VOLTAGE BEHAVIOUR
L
I
line
(A)
0.070.06
For line currents below 9 mA, the reference voltage is
automatically adjusted to a lower value; the VBB voltage
follows the SLPE voltage with a difference of 250 mV.
Any excess current available, other than for the purposes
of DC biasing the IC, will be small. At low reference
voltage, the IC has limited performance.
When voltage VBB falls below 2.7 V, it is detected by the
receive dynamic limiter circuit connected to pin LSAOand
is continuously activated, discharging the capacitor
connected to pin DLC. In the DC condition, the
loudspeaker is then automatically disabled below this
voltage.
When VBBfalls below 2.5 V, the TEA1098 is forced into a
lowvoltage mode irrespectiveof the logicinput levels. This
is a speech mode with reduced performance which only
enables the microphone channel (between the MICinputs
and pin LN) and the earpiece amplifier. These two
channels are able to deliver signals for line currents as
small as 3 mA. The HFC input is tied to GND sinking a
current of typically 300 µA.
1999 Oct 149
Page 10
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
8
10
handbook, full pagewidth
I
DD
(pA)
7
10
6
10
5
10
4
10
3
10
2
10
10
1.0
FCA050
1.52.53.0
2.0
VDD (V)
Fig.6 Current consumption on VDD.
POWER-DOWN MODE (PIN PD)
To reduce consumption during dialling or register recall
(flash), the TEA1098 is provided with a power-down input
(PD). When the voltage on pin PD is LOW, the current
consumption from VBB and VDD is reduced to typically
460 µA. Therefore a capacitor of 470 µF on VBB is
sufficient to power the TEA1098 during pulse dialling or
flash. The PD input has a pull-up structure. In this mode,
the capacitor C
is internally disconnected.
REG
Transmit channels (pins MIC+, MIC−, DTMF,
HFTX and LN)
HANDSET MICROPHONE AMPLIFIER (PINS MIC+, MIC−
AND LN)
The TEA1098 has symmetrical microphone inputs.
The input impedance between pins MIC+ and MIC− is
typically70 kΩ.The voltage gainbetweenpinsMIC+/MIC−
and LN is set to 44.3 dB. Without output limitation, the
microphone input stage can accept signals of up to
18 mV (RMS) at 2% THD (room temperature).
1999 Oct 1410
The microphone inputs are biased at a voltage of one
diode.
Automatic gain control is provided for line loss
compensation.
DTMF AMPLIFIER (PINS DTMF, LN AND RECO)
TheTEA1098 has anasymmetrical DTMF input.The input
impedance between DTMF and GND is typically 20 kΩ.
The voltage gain between pins DTMF and LN is set to
25.35 dB. Without output limitation, the input stage can
accept signals of up to 180 mV (RMS) at 2% THD (room
temperature).
When the DTMF amplifier is enabled, dialling tones may
be sent on the line. These tones can be heard in the
earpiece or in the loudspeaker ata lowlevel. This is called
theconfidence tone. Thevoltageattenuation between pins
DTMF and RECO is typically −16.5 dB. This input is
DC biased at 0 V.
The automatic gain control has no effect on these
channels.
Page 11
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
HANDSFREE TRANSMIT AMPLIFIER (PINS HFTX AND LN)
The TEA1098 has an asymmetrical HFTX input, which is
mainly intended for use in combination with the TXOUT
output. The input impedance between HFTX and GND is
typically 20 kΩ. The voltage gain between
pins HFTX and LN is set to 34.7 dB. Without output
limitation, the input stage can accept signals of up to
95 mV (RMS) at 2% THD (room temperature). The HFTX
input is biased at a voltage of two diodes.
Automatic gain control is provided for line loss
compensation.
Receive channels (pins IR, RECO, GARX and QR)
RX AMPLIFIER (PINS IR AND RECO)
The receive amplifier has one input (IR) which is
referenced to the line. The input impedance between pins
IR and LN is typically 20 kΩ and the DC bias between
these pins is equal to the voltage of one diode. The gain
between pins IR(referenced to LN) and RECO is typically
29.7 dB. Without output limitation, the input stage can
accept signals of up to 50 mV (RMS) at 2% THD (room
temperature).
The receive amplifier has a rail-to-rail output (RECO),
which is designed for use with high ohmic (real) loads of
more than 5 kΩ. This output is biased at a voltage of two
diodes.
Automatic gain control is provided for line loss
compensation.
AGC (pin AGC)
The TEA1098 performsautomatic lineloss compensation,
which fits well with the true line attenuation. The automatic
gain control varies the gain of some transmit and receive
amplifiers in accordance with the DC line current.
The controlrange is6.45 dB for G
and 6.8 dB for G
v(HFTX-LN)
, which corresponds
v(MIC-LN)
andG
v(IR-RECO),
approximately to a line length of 5.5 km for a 0.5 mm
twisted-pair copper cable.
To enable this gain control, the pin AGC must be shorted
to pin LN. The start current forcompensation corresponds
to a line current of typically 23 mA and a stop current of
57 mA. The start current can be increased by connecting
an external resistor between pins AGC and LN. It can be
increased by up to 40 mA (using a resistor of typically
80 kΩ). The start and stop current will be maintained at a
ratio of 2.5. By leaving the AGC pin open, the gain control
is disabled and no line loss compensation occurs.
Handsfree application
Figure 7 shows a loop is formed by the sidetone network
in the line interface section, and by the acoustic coupling
between loudspeaker and microphone in the handsfree
section. A loop-gain of greater than 1 causes howl.
To prevent howl in full duplex applications, the loop-gain
must be set much lower than 1. This is achieved by the
duplex controller which detects the channel with the
‘largest’ signal and controls the gains of the microphone
and the loudspeaker amplifiers so that the sum of their
gains remains constant.
EARPIECE AMPLIFIER (PINS GARX AND QR)
The earpiece amplifier is an operational amplifier which
has an output (QR) and an inverting input (GARX).
Its input signal is fed by a decoupling capacitor from the
receive amplifier output (RECO) to two resistorswhich set
the required gain or attenuation from −3 to +15 dB
compared to the receive gain.
Two external capacitors C
and QR) and C
ensure stability. The C
(connected between GAR and GND)
GARS
GAR
(connected between GAR
GAR
capacitor provides a first-order
low-pass filter. The cut-off frequency corresponds to the
time constant C
C
≥ 10 × C
GARS
× Re2. The relationship
GAR
must be satisfied.
GAR
The earpiece amplifierhas arail-to-rail output(QR) biased
at a voltage of two diodes. It is designed for use with low
ohmic (real) loads of 150 Ω, or capacitive loads of 100 nF
in series with 100 Ω.
1999 Oct 1411
Thereforein the handsfreeapplication,thecircuit can have
three stable modes:
1. Transmit mode (Tx mode).
The microphone amplifieris atmaximum gain, andthe
loudspeaker amplifier is at minimum gain.
2. Receive mode (Rx mode).
The microphoneamplifier is at minimum gain, and the
loudspeaker amplifier is at maximum gain.
3. Idle mode.
The microphone amplifier and the loudspeaker
amplifier are both midway between maximum and
minimum gain.
The difference between the maximum and minimum gain
is called the switching range.
Page 12
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
handbook, full pagewidth
acoustic
coupling
telephone
line
sidetone
HYBRID
Fig.7 Handsfree telephone set principles.
HANDSFREE MICROPHONE CHANNEL: PINS TXIN, GATX,
TXOUT AND GNDTX (see Fig.8)
TheTEA1098 has an asymmetricalhandsfreemicrophone
input (TXIN) with an input resistance of 20 kΩ.
The input DCbias is 0 V.Thegain oftheinput stage varies
according to the TEA1098 mode. In Tx mode, it has
maximum gain; in Rx mode, it has minimum gain, and in
Idle mode, it is midway between maximum and minimum
gain.
DUPLEX
CONTROL
MGM299
Switch-over from one mode to the other is smooth and
click-free. The output (TXOUT) is biased at a voltage of
two diodes and has a current capability of 20 µA (RMS).
In Tx mode, the overall gain of the microphone amplifier
(from pins TXIN to TXOUT) can be adjusted from
0 up to 31 dB to suit specific application requirements.
The gain is proportional to the value of R
15.2 dB whenR
is 30.1 kΩ. Withoutoutput limitation,
GATX
GATX
and equals
the microphone input stage can accept signals of up to
18 mV (RMS) at 2% THD (room temperature).
handbook, full pagewidth
V
BB
R
MIC
Pin numbers in parenthesis apply to the TEA1098H. Pin numbers not in parenthesis apply to the TEA1098TV.
C
MIC
31
(28)
TXIN
to
envelope
detector
V II V
from
voice
switch
GATX
TXOUT
GNDTX
MGL342
Fig.8 Handsfree microphone channel.
1999 Oct 1412
30
(27)
29
(26)
32
(29)
R
GATX
Page 13
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
LOUDSPEAKER CHANNEL
Loudspeaker amplifier: pins HFRX, GALS and LSAO
The TEA1098 loudspeaker amplifier has an asymmetrical
inputwith an input resistanceof20 kΩ between pinsHFRX
and GND. It is biased at a voltage of two diodes. Without
output limitation, the input stage can accept signals of up
to 580 mV (RMS) at 2% THD (room temperature).
The gain of the input stage varies according to the
TEA1098 mode. In Rx mode, it has maximum gain; in
Tx mode, it has minimum gain and in Idle mode, it is
halfway between maximum and minimum gain.
Switch-over from one mode to the other is smooth and
click-free.The rail-to-rail outputstageis designedtopower
aloudspeaker connected asasingle-ended load (between
pins LSAO and GND).
handbook, full pagewidth
R
C
C
LSAO
GALS
GALS
(11)
(12)
GALS
14
V
LSAO
15
BB
V I
In Rx mode, the overall gain of the loudspeaker amplifier
can be adjusted from 0 up to 35 dB to suit specific
application requirements. The gain from pin HFRX to pin
LSAO is proportional to the value of R
whenR
is connected in parallel with R
is 255 kΩ.It isrecommended that acapacitor
GALS
to provide a first-order
GALS
and is 28 dB
GALS
low-pass filter.
Volume control: pin VOL
The loudspeaker amplifier gain can be adjusted by the
potentiometer R
. For logarithmic gain control, a linear
VOL
potentiometer canbe used. Each1.9 kΩ increase ofR
resultsin again loss of 3 dB. Themaximum gainreduction
using the volume control is internally limited to the
switching range (see Fig.9).
to
logic
to/from
voice switch
I V
to
envelope
detector
HFRX
5
(1)
VOL
DLC
12
C
DLC
Pin numbers in parenthesis apply to the TEA1098H. Pin numbers not in parenthesis apply to the TEA1098TV.
(8)
DYNAMIC
LIMITER
Fig.9 Loudspeaker channel.
Dynamic limiter: pin DLC
The TEA1098 dynamic limiter prevents clipping of the
loudspeakeroutput stageandprotects theoperationof the
circuit when the supply voltage at VBB falls below 2.7 V.
Hardclipping ofthe loudspeaker outputstage isprevented
by rapidly reducing the gain when the output stage starts
to saturate. The time taken to effect gain reduction
(clipping attack time) is approximately a few milliseconds.
The circuit stays in the reduced gain mode until the peaks
of the loudspeaker signals no longer cause saturation.
The gain of the loudspeaker amplifier then returns to its
normal value within the clipping release time (typically
250 ms). Both attack and release times are proportional to
the value of the capacitor C
The total harmonic distortion of the loudspeaker output
stage, in reduced gain mode, stays below 2% up to 10 dB
(minimum) of input voltage overdrive [providing V
below 580 mV (RMS)].
When the supply voltage falls below an internal threshold
voltage of 2.7 V, the gain of the loudspeaker amplifier is
reduced rapidly (approximately 1 ms). When the supply
voltage rises above 2.7 V, the gain of the loudspeaker
amplifier is increased. By forcing a level lower than 0.2 V
on pin DLC, the loudspeaker amplifier is muted and the
TEA1098 is automatically forced into the Tx mode.
VOLUME
CONTROL
VOL
MGL343
DLC
26
(23)
.
R
VOL
HFRX
is
1999 Oct 1413
Page 14
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
DUPLEX CONTROLLER
Signal and noise envelope detectors: pins TSEN, TENV,
TNOI, RSEN, RENVand RNOI
The strength of signal level and background noise in both
channels is monitored by signal envelope detectors and
noise envelope detectors respectively. The outputs of the
envelope detectors provide inputs to the decision logic.
The signal and noise envelope detectors are shown in
Fig.10.
For the transmitchannel, thesignal betweenpin TXIN and
pin TSEN is amplified by 40 dB. For the receive channel,
the signal between pin HFRX and pin RSEN is amplified
by 0 dB.
The signals between pin TSEN and pin TENV, and
between pin RSEN and pin RENV are logarithmically
compressed and buffered.
The sensitivity of the envelope detectors is set by
resistors R
TSEN
and R
. The capacitors connected in
RSEN
series with these two resistors block any DC component
and form a first-order high-pass filter.
In the basic application, (see Fig.19), it is assumed that
V
= 1 mV (RMS) and V
TXIN
and R
capacitors C
TSEN
and R
TSEN
both have a value of 10 kΩ. When
RSEN
and C
RSEN
= 100 mV (RMS) nominal
HFRX
both have a value of 100 nF,
the cut-off frequency is at 160 Hz.
The buffer amplifiers feeding the compressed signals to
pins TENV and RENV have a maximum source current of
120 µA and a maximum sink current of 1 µA. Capacitors
C
TENV
and C
set the timing of both signal envelope
RENV
detectors. In the basic application, the value of both
capacitors is 470 nF. Because of the logarithmic
compression, each6 dB signal increase means an 18 mV
increase on the signal envelopes at pins TENV or RENV
(room temperature). Thus, timings can be expressed in
dB/ms. At room temperature, the 120 µA sourced current
corresponds to a maximum signal envelope rise-slope of
85 dB/ms, which is sufficient to track normal speech
signals. The 1 µA current sunk by pin TENV or pin RENV
corresponds to a maximumfall-slope of0.7 dB/ms. This is
sufficient for a smooth envelope and also eliminates the
effect of echoes on switching behaviour.
handbook, full pagewidth
Pin numbers in parenthesis apply to the TEA1098H. Pin numbers not in parenthesis apply to the TEA1098TV.
DUPLEX CONTROLLER
LOG
from
microphone
amplifier
TSEN
8 (4)7 (3)6 (2)10 (6)11 (7)9 (5)
R
TSEN
C
TSEN
LOG
from
loudspeaker
amplifier
TENVTNOIRSENRENVRNOI
R
C
TENV
C
TNOI
C
Fig.10 Signal and noise envelope detectors.
RSEN
RSEN
C
RENV
to logicto logic
C
RNOI
MGL344
1999 Oct 1414
Page 15
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
To determine the noise level, the signals between
pin TENV and pin TNOI, and between pin RENV and
pin RNOI are buffered. The buffers have a maximum
source current of 1 µA and a maximum sink current of
120 µA.
Capacitors C
TNOI
and C
set the timing of both noise
RNOI
envelope detectors. In the basic application, see Fig.19,
the value of both capacitors is 4.7 µF.
At room temperature, the 1 µA sourced current
corresponds to a maximum noise envelope rise-slope of
approximately 0.07 dB/ms which is small enough to track
background noise without being affected by speech
bursts.
handbook, full pagewidth
INPUT SIGNAL
4 mV (RMS)
The 120 µA sink current corresponds to a maximum
fall-slope of approximately 8.5 dB/ms. However, because
the noiseenvelope tracks thefall of the signal envelope, it
will never fall faster than approximately 0.7 dB/ms.
The behaviour of the signal envelope and noise envelope
detectors is illustrated in Fig.11.
MBG354
1 mV (RMS)
SIGNAL ENVELOPE
A: 85 dB/ms
B: 0.7 dB/ms
NOISE ENVELOPE
B: 0.7 dB/ms
C: 0.07 dB/ms
A
C
36 mV
36 mV
Fig.11 Signal and noise envelope waveforms.
Decision logic: pins IDTand SWT
TheTEA1098 selects itsmode of operation(Tx, Rx orIdle)
by comparing the signal and noise envelopes of both
channels. This is executed by the decision logic.
The resulting voltage on pin SWT is the input to the voice
switch.
To facilitate the distinction between signal and noise, the
signal is considered as speech when its envelope is more
than 4.3 dB above the noise envelope. At room
temperature, this is equal to a voltage difference of
A
C
B
B
time
V
B
B
ENV
− V
= 13 mV. This so called speech/noise
NOI
threshold is implemented in both channels.
The signal on pin TXIN contains both speech and the
acoustically coupled signal from the loudspeaker.
In Rx mode, theloudspeaker signal overrides the speech.
Therefore, the signal envelope on pin TENV consists
mainly of the loudspeaker signal. To correct this, an
attenuator is connected between pin TENV and the
TENV/RENV comparator. Its attenuation is equal to that
applied to the microphone amplifier.
1999 Oct 1415
Page 16
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
Whena dialtone is present on theline, withoutmonitoring,
it would be recognized as noise because it has a constant
amplitude. This would cause the TEA1098 to go into Idle
mode, and the user would hear the dial tone fade away.
To prevent this, a dial tone detector monitorsinput signals
between pins HFRX and GND. In standard applications,
the detector does not consider a signal level above
25 mV (RMS) to be noise. This level is proportional to the
value of R
. Similarly, a transmit detector monitors
RSEN
input signals between pins TXIN and GNDTX. Instandard
applications the detector does not consider a signal level
above 0.75 mV (RMS) to be noise. This level is
proportional to the value of R
handbook, full pagewidth
(3) 7
(2) 6
TSEN.
DUPLEX CONTROLLER
TENV
TNOI
13 mV
ATTENUATOR
Figure 12 shows that the output of the decision logic is a
current source. The logic table shows the relationship
between the input levels and the value of the current
source. The current source can charge or discharge the
capacitor C
at a switch-over current of 10 µA. If the
SWT
current is zero, the voltage on pin SWT becomes equal to
the voltage on pin IDT via the high-ohmic resistor R
IDT
(idling). The resulting voltage difference between pins
SWT and IDT can vary between −400 and +400 mV and
determines the TEA1098 mode (see Table 1).
28 (25)
IDT
V
ref
(1)
LOGIC
SWT
27 (24)
R
IDT
XX11−10 µA
RENV
(7) 11
RNOI
(5) 9
13 mV
V
from logic
from dynamic
(1) When DLC < 0.2 V, −10 µA is forced.
Pin numbers in parenthesis apply to the TEA1098H. Pin numbers not in parenthesis apply to the TEA1098TV.
dt
limiter
X10X
1X0X
XX10 0
000X 0
+10 µA
+10 µA
Fig.12 Decision logic.
MGL345
C
SWT
1999 Oct 1416
Page 17
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
Table 1 TEA1098 modes
V
− V
SWT
(mV)MODE
IDT
< −180Tx mode
0Idle mode
> 180Rx mode
The switch-over timing can be set by capacitor C
the Idle mode timing can be set by capacitor C
resistor R
is 220 nF and R
.In the basicapplication given inFig.19,C
IDT
is 2.2 MΩ. This enables a switch-over
IDT
SWT
SWT
and
and
SWT
time from Tx to Rx mode or vice-versa of approximately
13 ms (580 mV swing on pin SWT). The switch-over time
from Idle mode to Tx or Rx mode is approximately 4 ms
(180 mV swing on pin SWT).
The switch-over time, from Rx or Tx mode to Idle mode is
equal to 4 × R
IDTCSWT
and is approximately 2 seconds
(Idle mode time).
The DLC input overrides the decision logic. When the
voltage on pin DLC falls below 0.2 V, the capacitor C
SWT
is discharged by 10 µA which selects Tx mode.
Voice switch: pins STAB and SWR
Figure 13 is a diagram of the voice switch. With a voltage
onpin SWT, the TEA1098voiceswitchregulates the gains
of the transmitand thereceive channelsso thatthe sum of
both is held constant.
In Tx mode, the microphone amplifier is at maximum gain
and the loudspeaker amplifier is at minimum gain.
In Rx mode, their gains are the opposite. In Idle mode,
both microphone and loudspeaker amplifiers are midway
between maximum and minimum gain.
The difference between the maximum and minimum gain
is called the switching range. This range is determined by
the ratio of resistors R
SWR
to R
between 0 and 52 dB. Resistor R
and is adjustable
STAB
should be 3.65 kΩ
STAB
which sets an internally used reference current. In the
basic application diagram (Fig.19), resistor R
SWR
is
365 kΩ which results in a switching range of 40 dB.
The switch-over behaviour is illustrated in Fig.14.
In Rx mode, the gain of the loudspeaker amplifier can be
reduced using the volume control. At the same time, the
gainof the microphoneamplifierincreases, sincethevoice
switch keeps the sum of the gains constant (see dashed
curves in Fig.14). However, in Tx mode, the volume
control has no effect on the gains of the microphone or
loudspeakeramplifiers.Consequently,theswitchingrange
is reduced when the volume is reduced. At maximum
reduction of volume, the switching range is 0 dB.
lfpage
(1) C = constant.
Pin numbers in parenthesis apply to the TEA1098H.
Pin numbers not in parenthesis apply to the TEA1098TV.
DUPLEX CONTROLLER
to
microphone
amplifier
G
vtx
VOICE SWITCH
from
volume
control
loudspeaker
+ G
vrx =
to
amplifier
from
SWT
C
R
24 (21)
STAB
(1)
25 (22)
SWR
MGL346
STAB
R
SWR
Fig.13 Voice switch.
1999 Oct 1417
handbook, halfpage
G
G
vrx
vtx,
(10 dB/div)
−400−2000+400+200
SWT
− V
MGM305
IDT
idle
Tx modeRx mode
G
vtx
G
vrx
mode
V
Fig.14 Switch-over behaviour.
(mV)
R
VOL
(Ω)
11400
7600
3800
0
0
3800
7600
11400
Page 18
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
Logic inputs
Table 2 Selection of transmit and receive channels for 5 different application modes
LOGIC INPUTS
FEATURESAPPLICATION EXAMPLES
PDHFCMUTE
0XXflash, DC dialling
100DTMF to LN; DTMF to RECO; QR and MICS
DTMF dialling in handset mode
are active
101MICS to LN; IR to RECO; QR and MICS are
handset conversation
active
110DTMF to LN; DTMF to RECO; HFRX to LSAO;
DTMF dialling in handsfree
QR and MICS are active
111TXIN to TXOUT; HFTX to LN; IR to RECO;
handsfree conversation mode
HFRX to LSAO; MICS is active
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134); all DC levels are referenced to GND.
SYMBOLPARAMETERCONDITIONSMIN.MAX.UNIT
V
LN
positive continuous line voltage−0.4+12V
repetitive line voltage during switch-on or line
−0.4+13.2V
interruption
V
n(max)
I
line
P
tot
maximum voltage on pins REG, SLPE, IR and AGC−0.4VLN+ 0.4 V
maximum voltage on all other pins except V
DD
−0.4VBB+ 0.4 V
maximum line current−130mA
total power dissipationT
amb
=75°C
TEA1098TV (see Fig.15)−400mW
TEA1098H (see Fig.16)−720mW
TEA1098UH; note 1−−
T
stg
T
amb
T
j
IC storage temperature−40+125°C
ambient temperature−25+75°C
junction temperature−125°C
Note
1. Mostly dependent on the maximum required ambienttemperature, on the voltage between LN and SLPEand on the
thermal resistance between die ambient temperature. This thermal resistance depends on the application board
layoutand onthe materials used.Figure 17 showsthe safe operating area versusthis thermal resistance for ambient
temperature T
VSO40: plastic very small outline package; 40 leads
D
y
Z
40
pin 1 index
SOT158-1
E
c
H
E
21
A
2
A
1
L
p
L
A
X
v M
A
Q
(A )
A
3
θ
1
e
0510 mm
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
mm
OUTLINE
VERSION
SOT158-1
A
max.
2.70
0.11
1
0.3
0.1
0.012
0.004
A2A
2.45
2.25
0.096
0.089
IEC JEDEC EIAJ
3
0.25
0.010
b
p
0.42
0.30
0.017
0.012
0.22
0.14
0.0087
0.0055
UNITA
inches
Notes
1. Plastic or metal protrusions of 0.4 mm maximum per side are not included.
2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.
(1)E(2)
cD
15.6
15.2
0.61
0.60
REFERENCES
20
w M
b
p
scale
eHELLpQywvθ
7.6
0.7622.25
7.5
0.30
0.030.089
0.29
12.3
11.8
0.48
0.46
1.7
1.5
0.067
0.059
detail X
1.15
0.2
1.05
0.045
0.0080.004
0.041
EUROPEAN
PROJECTION
0.10.1
0.004
(1)
Z
0.6
0.3
0.024
0.012
ISSUE DATE
92-11-17
95-01-24
o
7
o
0
1999 Oct 1433
Page 34
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
QFP44: plastic quad flat package; 44 leads (lead length 1.3 mm); body 10 x 10 x 1.75 mm
c
y
X
A
3323
34
pin 1 index
44
1
22
Z
E
e
H
E
E
w M
b
p
12
11
A
2
A
A
1
detail X
SOT307-2
(A )
3
θ
L
p
L
w M
b
e
p
D
H
D
Z
D
B
02.55 mm
scale
DIMENSIONS (mm are the original dimensions)
A
UNITA1A2A3b
max.
0.25
mm
2.10
0.05
1.85
1.65
0.25
cE
p
0.40
0.25
0.20
0.14
(1)
(1)(1)(1)
D
10.1
9.9
eH
10.1
9.9
12.9
0.81.3
12.3
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
OUTLINE
VERSION
IEC JEDEC EIAJ
REFERENCES
SOT307-2
1999 Oct 1434
v M
H
D
v M
A
B
E
12.9
12.3
LL
p
0.95
0.55
0.15 0.10.15
EUROPEAN
PROJECTION
Z
D
1.2
0.8
Zywvθ
E
o
1.2
10
o
0.8
0
ISSUE DATE
95-02-04
97-08-01
Page 35
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
SOLDERING
Introduction to soldering surface mount packages
Thistext gives averybrief insight toa complex technology.
A more in-depth account of soldering ICs can be found in
our
“Data Handbook IC26; Integrated Circuit Packages”
(document order number 9398 652 90011).
There is no soldering method that is ideal for all surface
mount IC packages.Wave solderingis notalways suitable
for surface mount ICs, or for printed-circuit boards with
high population densities. In these situations reflow
soldering is often used.
Reflow soldering
Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
tothe printed-circuitboardby screenprinting,stencilling or
pressure-syringe dispensing before package placement.
Several methods exist for reflowing; for example,
infrared/convection heating in a conveyor type oven.
Throughput times (preheating, soldering and cooling) vary
between 100 and 200 seconds depending on heating
method.
Typical reflow peak temperatures range from
215 to 250 °C. The top-surface temperature of the
packages should preferable be kept below 230 °C.
Wave soldering
Conventional single wave soldering is not recommended
forsurface mount devices(SMDs)or printed-circuit boards
with a high component density, as solder bridging and
non-wetting can present major problems.
• For packages with leads on two sides and a pitch (e):
– larger than or equal to 1.27 mm, the footprint
longitudinal axis is preferred to be parallel to the
transport direction of the printed-circuit board;
– smaller than 1.27 mm, the footprint longitudinal axis
must be parallel to the transport direction of the
printed-circuit board.
The footprint must incorporate solder thieves at the
downstream end.
• Forpackages with leadsonfour sides, thefootprintmust
be placedat a 45° angle to the transport direction of the
printed-circuit board. The footprint must incorporate
solder thieves downstream and at the side corners.
During placement and before soldering, the package must
be fixed with a droplet of adhesive. The adhesive can be
applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the
adhesive is cured.
Typical dwell time is 4 seconds at 250 °C.
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
Manual soldering
Fix the component by first soldering two
diagonally-opposite end leads. Use a low voltage (24 V or
less) soldering iron applied to the flat part of the lead.
Contact time must be limited to 10 seconds at up to
300 °C.
When using a dedicated tool, all other leads can be
soldered in one operation within 2 to 5 seconds between
270 and 320 °C.
To overcome these problems the double-wave soldering
method was specifically developed.
If wave soldering is used the following conditions must be
observed for optimal results:
• Use a double-wave soldering method comprising a
turbulent wavewith high upwardpressure followed bya
smooth laminar wave.
1999 Oct 1435
Page 36
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
Suitability of surface mount IC packages for wave and reflow soldering methods
1. All surface mount (SMD) packages are moisture sensitive. Depending upon the moisture content, the maximum
temperature (with respect to time) and body size of the package, there is a risk that internal or external package
cracks may occur due to vaporization of the moisture in them (the so called popcorn effect). For details, refer to the
Drypack information in the
2. These packages are not suitable for wave soldering as a solder joint between the printed-circuit board and heatsink
(at bottom version) can not be achieved, and as solder may stick to the heatsink (on top version).
3. If wave soldering is considered, then the package must be placed at a 45° angle to the solder wave direction.
The package footprint must incorporate solder thieves downstream and at the side corners.
4. Wave soldering is only suitable for LQFP, TQFP and QFP packages with a pitch (e) equal to or larger than 0.8 mm;
it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
5. Wave soldering is onlysuitable for SSOP and TSSOPpackages with a pitch (e) equal toor larger than 0.65 mm; it is
definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.
1999 Oct 1436
Page 37
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
DEFINITIONS
Data sheet status
Objective specificationThis data sheet contains target or goal specifications for product development.
Preliminary specificationThis data sheet contains preliminary data; supplementary data may be published later.
Product specificationThis data sheet contains final product specifications.
Limiting values
Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or
more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation
of the device at these or at any other conditions above those given in the Characteristics sections of the specification
is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information
Where application information is given, it is advisory and does not form part of the specification.
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such
improper use or sale.
BARE DIE DISCLAIMER
All die are tested and are guaranteed to comply with all data sheet limits up to the point of wafer sawing for a period of
ninety (90) days from the date of Philips' delivery. If there are data sheet limits not guaranteed, these will be separately
indicated in the data sheet. There is no post waffle pack testing performed on individual die. Although the most modern
processes are utilized for wafer sawing and die pick and place into waffle pack carriers, Philips Semiconductors has no
control of third party procedures in the handling, packing or assembly of the die. Accordingly, Philips Semiconductors
assumes no liability for device functionality or performance of the die or systems after handling, packing or assembly of
the die. It is the responsibility of the customer to test and qualify their application in which the die is used.
1999 Oct 1437
Page 38
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
NOTES
1999 Oct 1438
Page 39
Philips SemiconductorsProduct specification
Speech and handsfree ICTEA1098
NOTES
1999 Oct 1439
Page 40
Philips Semiconductors – a w orldwide compan y
Argentina: see South America
Australia: 3 Figtree Drive, HOMEBUSH, NSW 2140,
United States: 811 East Arques Avenue, SUNNYVALE, CA 94088-3409,
Tel. +1 800 234 7381, Fax. +1 800 943 0087
Uruguay: see South America
Vietnam: see Singapore
Yugoslavia: PHILIPS, Trg N. Pasica 5/v, 11000 BEOGRAD,
Tel. +381 11 62 5344, Fax.+381 11 63 5777
For all other countries apply to: Philips Semiconductors,
International Marketing & Sales Communications, Building BE-p, P.O. Box 218,
5600 MD EINDHOVEN, The Netherlands, Fax. +31 40 27 24825
The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed
without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license
under patent- or other industrial or intellectual property rights.
1999
Internet: http://www.semiconductors.philips.com
68
Printed in The Netherlands465002/04/pp40 Date of release: 1999 Oct 14Document order number: 9397 750 06403
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