Philips tea1083 DATASHEETS

INTEGRATED CIRCUITS

DATA SH EET

TEA1083; TEA1083A

Call progress monitor for line powered telephone sets

Product speciﬁcation File under Integrated circuits, IC03A

March 1994

Philips Semiconductors Product speciﬁcation

Call progress monitor for line powered telephone sets

FEATURES

• Internal supply – Optimum current split-up – Low constant current (adjustable) in transmission IC – Nearly all line current available for monitoring – Stabilized supply voltage

• Loudspeaker amplifier with a fixed gain of 35 dB

• Volume controlled by potentiometer

• Power-down input (TEA1083A only)

• Loudspeaker enable input.

GENERAL DESCRIPTION

The TEA1083/83A is a bipolar IC which has been designed for use in line powered telephone sets. It is intended to offer a monitoring facility of the line signal via

TEA1083; TEA1083A

a loudspeaker during on-hook dialling. The TEA1083/83A is intended for use in conjunction with a transmission circuit of the TEA1060 family. The device uses a part of the available line current via the internal supply circuit. The loudspeaker amplifier, which consists of a preamplifier and a power amplifier, amplifies the received line signals from the transmission circuit when enabled via the LSE input. The loudspeaker amplifier can also be used to amplify dialling tones from the dialler IC. The power amplifier contains a push-pull output stage to drive the loudspeaker in a Single Ended Load (SEL) configuration. The internal voltage stabilizer can be used to supply external devices. By activating the power-down (PD) input of the TEA1083A, the current consumption of the circuit will be reduced, this enables pulse dialling or flash (register recall). An internal start circuit ensures normal start-up of the transmission IC.

QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

SUP

amb

input current range 3.0 − 120 mA stabilized supply current − 2.95 − V current consumption PD = HIGH; TEA1083A only − 50 −µA voltage gain of loudspeaker ampliﬁer − 35 − dB minimum input current PO = 10 mW (typ) into 50 Ω− 10 − mA operating ambient temperature range −25 −+75 °C

ORDERING INFORMATION

EXTENDED TYPE

NUMBER

PINS PIN POSITION MATERIAL CODE

TEA1083 8 DIL PLASTIC SOT97D TEA1083A 16 DIL PLASTIC SOT38 TEA1083AT 16 SOL PLASTIC SOT162AG

PACKAGE

(1)

(2)

(3)

Notes

1. SOT97-1; 1998 Jun 18.

2. SOT38-1; 1998 Jun 18.

3. SOT162-1; 1998 Jun 18.

March 1994 2

Philips Semiconductors Product speciﬁcation

Call progress monitor for line powered telephone sets

handbook, full pagewidth

SREF

LSI1 LSI2

LSE

1 4

SUP

SUPPLY

PRE-

AMPLIFIER

ENABLE CIRCUIT

START-

CIRCUIT

POWER

AMPLIFIER

TEA1083

MGR045

TEA1083; TEA1083A

QLS

handbook, full pagewidth

SREF

LSI1 LSI2

LSE

Fig.1 Block diagram (TEA1083).

3 12

1 8

3, 5, 6, 7, 10, 11, 14

n.c.

SUP

SUPPLY

PRE-

AMPLIFIER

ENABLE CIRCUIT

START-

CIRCUIT

POWER

AMPLIFIER

TEA1083A

TEA1083AT

MGR046

QLS

Fig.2 Block diagram (TEA1083A/AT).

March 1994 3

Philips Semiconductors Product speciﬁcation

Call progress monitor for line powered telephone sets

handbook, halfpage

SREF

LSI1

1 2 3 4

TEA1083

MGR047

QLSSUP

LSE

LSI2

Fig.3 Pin configuration (TEA1083).

handbook, halfpage

Fig.4 Pin configuration (TEA1083A/AT).

SUP

n.c.

SREF

n.c. n.c. n.c.

LSI1

TEA1083; TEA1083A

1 2 3 4

TEA1083A

TEA1083AT

5 6 7 8

MGR048

QLS

n.c.

LSE

n.c.

LSI2

PINNING

SYMBOL

DIL16

DIL8

1 1 negative supply terminal SUP 2 2 positive supply terminal n.c. 3 − not connected SREF 4 3 supply reference input n.c. 5 − not connected n.c. 6 − not connected n.c. 7 − not connected LSI1 8 4 loudspeaker ampliﬁer input 1 LSI2 9 5 loudspeaker ampliﬁer input 2 n.c. 10 − not connected n.c. 11 − not connected PD 12 − power-down input LSE 13 6 loudspeaker enable input n.c. 14 − not connected QLS 15 7 loudspeaker ampliﬁer output V

16 8 stabilized supply voltage

DESCRIPTION

March 1994 4

Philips Semiconductors Product speciﬁcation

Call progress monitor for line powered

TEA1083; TEA1083A

telephone sets

Table 1 Comparison of the TEA108X family.

PRODUCT CONDITIONS TEA1083 TEA1083A TEA1085/85A

Application area note 1 call progress monitoring listening-in PD facility − XX MUTE or LSE facility note 2 X X X Dynamic limiter −− X Howling limiter −− X V

setting −− X

SEL note 3 X X X BTL note 3 −− X Number of pins note 4 8 16 24

Notes

1. A call progress monitor is recommended by the European Telecommunications Standards Institute (ETSI) for telephone sets with automatic on-hook dialling facilities so that audible, or visual, progress of a call attempt can be monitored. In accordance with the ETSI (at a frequency of 440 Hz and a line level of 20 dBm (600 Ω)), a minimum level of 50 dBA shall be guaranteed at a distance of 50 cm from the set. This corresponds to a minimum level of approximately 100 mV (RMS) (PO≥ 0.2 mW) across a loudspeaker; Philips type AD2071/Z50.

A listening-in set has to offer the user more facilities e.g. howling limiting to reduce annoying loudspeaker and line signals. Dynamic limiting of the loudspeaker signal, with respect to supply conditions, can also be required. Acoustic output levels for listening-in sets are approximately 70 to 75 dBA. This corresponds to a loudspeaker level of approximately 1 mV (RMS) (PO≈ 20 mW).

2. The MUTE function of the TEA1085A has a logic input; the MUTE function of the TEA1085 has a toggle input.

3. SEL: loudspeaker connected in a single-ended-load configuration BTL: loudspeaker connected in a bridge-tied-load configuration

4. Consult the product specification for the package outline/s.

FUNCTIONAL DESCRIPTION

The TEA1083/83A is normally used in conjunction with a transmission circuit of the TEA1060 family. The circuit must be connected between the positive line terminal (pin 2) and pin SLPE of the transmission IC. The transmission characteristics (impedance, gain settings, etc.) are not affected. An interconnection between the TEA1083/83A and a member of the TEA1060 family is illustrated in Fig.5.

Supplies SUP, SREF, V

and V

In Fig.6 the line current is divided into ITR for the transmission IC and I

for the monitoring circuit

SUP

TEA1083/83A. ITR is constant: ITR=V I

SUP=Iline

/ R20

int

− ICC− I

Where:

• V

is an internal temperature compensated reference

int

voltage of 500 mV (typ) between pins SUP and SREF

• R20 is a resistor connected between SUP and SREF

• ICC is the internal current consumption of the TEA106X

(approximately 1 mA).

A practical value for resistor R20 is 150 Ω; this produces a current of approximately 3.3 mA (typ) for ITR and I approximately equal to I

− 4.3 mA.

line

SUP

March 1994 5

Philips Semiconductors Product speciﬁcation

Call progress monitor for line powered telephone sets

The circuit stabilizes its own supply voltage at VBB. Transistor TR1 provides the supplies for the internal circuits. Transistor TR2 is used to minimize signal distortion on the line by momentarily diverting the input current to VSS whenever the instantaneous value of the voltage at V fixed to a typical value of 2.95 V. The supply at VBB is decoupled with respect to VSS by a 220 µF capacitor (C20).

The DC voltage (V transmission IC and V V

− VSS = V

SUP

The reference voltage of the transmission IC has to be adjusted to a level where V 400 mV. The minimum voltage space between SUP and VBB (400 mV) is required to maintain a 'high' efficiency of the internal supply for mean speech levels. V specified maximum level.

The internal current consumption of the TEA1083/83A (I

) is typically 2.5 mA (where V

SUP0

The current I

0.4 mA) for the circuitry connected to SUP and I

(approximately 2.1 mA) for the internal circuitry connected to VBB(see Fig.6).

LOUDSPEAKER AMPLIFIER (LSI1/LSI2 and QLS)

The TEA1083/83A has symmetrical inputs at LSI1 and LSI2. The input signal is normally taken from the earpiece output of the transmission circuit (see Fig.5) and/or from the signal output of the DTMF generator via a resistive attenuator. The attenuation factor must be chosen in accordance with the output levels from the transmission IC and/or DTMF generator and, in accordance with the required output power and permitted signal distortion from the loudspeaker signal.

The output QLS drives the loudspeaker as a single-ended load. The output stage has been optimized for use with a 50 Ω loudspeaker (e.g. Philips type AD2071). The loudspeaker amplifier is enabled when the LSE input goes HIGH. The gain of the amplifier is fixed at 35 dB.

Volume control of the loudspeaker signal can be obtained by using a level control at the input (see Fig.5).

drops below the supply voltage VBB. VBB is

SUP

− VSS) is determined by the

SUP

; thus

int

+ V

LN−SLPE

consists of currents I

SUP0

int

SUP

− V

SUP

is greater than

BB (max)

− VSS= 3.6 V). (approximately

BIAS

BB0

is the

TEA1083; TEA1083A

The maximum voltage swing at the QLS output is V V I available voltage space (VBB). Higher input levels and/or lower supply currents will result in an increase of the harmonic distortion due to signal clipping.

With a limit of 2.5 V (p-p), the maximum output swing is dependent on the supply current and loudspeaker impedance. It can be approximated, for low distortions, by the following equation:

V Where;

• V

• RLS= the loudspeaker impedance

• I

POWER-DOWN INPUT (PD)

During pulse dialling or register recall (timed loop break) the telephone line is interrupted, thereby breaking the supply current to the transmission IC. The capacitor connected to V TEA1083/83A during the supply breaks.

By making the PD input HIGH during the loop break, the requirement on the capacitor is eased and, consequently, the internal current consumption I reduced from 2.1 mA to 400 µA typically. Transistors TR1 and TR2 are inhibited during power-down and the bias current is reduced from approximately 400 µA to approximately 50 µA with V equation:

I Where 3.6 < V 2Vd is the voltage drop across 2 internal diodes

(approximately 1.3 V) Ra is an internal resistor (typical 50 kΩ)

LOUDSPEAKER ENABLE INPUT (LSE)

The LSE input has a pull-down structure. It switches the loudspeaker amplifier, in the monitoring condition, by applying a HIGH level at the input. The amplifier is in the standby condition when LSE is LOW (input open-circuit or connected to V

= 2.5 V (typical with 50 Ω load). The input level

O(p-p)

is approximately 16 mV(rms) and the supply current

LSI

> 11 mA. In this condition the signal is limited by the

SUP

O(p-p)

SUPO

SUP(PD)

=2×(I

= the peak-to-peak level of the loudspeaker

= 2.5 mA (typ.)

= I

BIAS(PD)

− I

SUP

provides the supply for the

= (V

< VBB+ 3V

SUP

) ×π×R

SUPO

SUP

− 2Vd)/Ra

SUP

(see Fig.5) is

BB0

= 3.6 V in the following

March 1994 6

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