Philips tea1093 DATASHEETS

INTEGRATED CIRCUITS

DATA SH EET

TEA1093

Hands-free IC

Product speciﬁcation Supersedes data of 1995 May 18 File under Integrated Circuits, IC03

1996 Feb 09

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

FEATURES

• Line powered supply with: – adjustable stabilized supply voltage – power down function

• Microphone channel with: – externally adjustable gain – microphone mute function

• Loudspeaker channel with: – externally adjustable gain – dynamic limiter to prevent distortion – rail-to-rail output stages for single-ended or

bridge-tied load drive – logarithmic volume control via linear potentiometer – loudspeaker mute function

• Duplex controller consisting of: – signal envelope and noise envelope monitors for both

channels with: externally adjustable sensitivity externally adjustable signal envelope time constant externally adjustable noise envelope time constant

– decision logic with:

externally adjustable switch-over timing externally adjustable idle mode timing externally adjustable dial tone detector in receive

channel

– voice switch control with:

adjustable switching range constant sum of gain during switching constant sum of gain at different volume settings.

APPLICATIONS

• Line-powered telephone sets with hands-free/listening-in functions.

GENERAL DESCRIPTION

The TEA1093 is a bipolar circuit intended for use in line-powered telephone sets. In conjunction with a member of the TEA1060 family or PCA1070 transmission circuits, the device offers a hands-free function for line powered telephone sets. It incorporates a supply, a microphone channel, a loudspeaker channel and a duplex controller with signal and noise monitors on both channels.

ORDERING INFORMATION

TYPE NUMBER

NAME DESCRIPTION VERSION

TEA1093 DIP28 plastic dual in-line package; 28 leads (600 mil) SOT117-1

TEA1093T SO28 plastic small outline package; 28 leads; body width 7.5 mm SOT136-1

1996 Feb 09 2

PACKAGE

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

QUICK REFERENCE DATA

= 4.2 V; V

SREF

RL=50Ω; R

VOL

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

SUP

BB(pd)

operating supply current (pin SUP) 7 − 140 mA stabilized supply voltage 3.35 3.6 3.85 V current consumption from pin VBB in

power-down condition

SUP(pd)

current consumption from pin SUP in power-down condition

vtx

voltage gain from pin MIC to pin MOUT in

transmit mode ∆G G

∆G V

O(p-p)

vtxr

vrx

vrxr

voltage gain adjustment with R

voltage gain in receive mode V

voltage gain adjustment with R

bridge-tied load (peak-to-peak value) V

SWRA switching range − 40 − dB ∆SWRA switching range adjustment with R

referenced to R T

amb

operating ambient temperature −25 − +75 °C

GND

=0V; I

= 15 mA; V

SUP

= 0 V (RMS); f = 1 kHz; T

SUP

=25°C; PD=LOW; MUTET = LOW;

amb

=0Ω; measured in test circuit of Fig.15; unless otherwise speciﬁed.

PD = HIGH; VBB= 3.6 V − 400 550 µA

GAT

the difference between RIN1 and RIN2 to LSP1 or LSP2 single-ended load

PD = HIGH; V

= 1 mV (RMS);

MIC

= 30.1 kΩ

GAT

= 20 mV (RMS);

RIN

= 66.5 kΩ;

GAR

RL=50Ω

= 4.5 V − 55 75 µA

sup

the difference between RIN1 and RIN2 to the difference between LSP1 and LSP2 bridge-tied load

GAR

= 150 mV (RMS);

RIN

RL=33Ω; note 1

SWR

= 365 kΩ

SWR

12.5 15 17.5 dB

−10 − +10 dB

15.5 18 20.5 dB

21.5 24 26.5 dB

−15 − +15 dB

− 5.15 − V

−40 − +12 dB

Note

1. Corresponds to 100 mW output power.

1996 Feb 09 3

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

BLOCK DIAGRAM

handbook, full pagewidth

TEA106X

TSEN

TENV

TNOI

RNOI

RENV

MIC

TSEN

SUP

315 mV

SREF

MUTET

MIC

TSEN

V V

MICROPHONE CHANNEL

V I

DUPLEX CONTROLLER

LOG

TR1

SWITCH

SUPPLY

TR2

to dynamic

limiter

VOLTAGE

STABILIZER

POWER

DOWN

I V

TEA1093

BUFFER

TENV

13 mV

TNOI

RNOI

RENV

BUFFER

ATTENUATOR

13 mV

LOGIC

VOICE

SWITCH

GAT

MOUT

MICGND

IDT

ref

SWT

STAB

SWR

8GND

VBB

GAT

to TEA106X

IDT

SWT

STAB

SWR

RSEN

LSP1

GAR

DLC

RSEN

GAR

LSP1

DLC/

MUTER

LSP2

from voltage

stabilizer

DYNAMIC

LIMITER

LOG

−1 LOUDSPEAKER CHANNEL

Fig.1 Block diagram.

1996 Feb 09 4

V I

I V

VOLUME

CONTROL

RIN1

RIN2

VOL 11

from TEA106X

MGD216

VOL

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

PINNING

SYMBOL PIN DESCRIPTION

MUTER 1 dynamic limiter timing adjustment,

DLC/

receiver channel mute input RIN1 2 receiver ampliﬁer input 1 RIN2 3 receiver ampliﬁer input 2 LSP2 4 loudspeaker ampliﬁer output 2 GAR 5 receiver gain adjustment LSP1 6 loudspeaker ampliﬁer output 1 SREF 7 supply reference input GND 8 ground reference SUP 9 supply input V

10 stabilized supply output VOL 11 receiver volume adjustment SWR 12 switching range adjustment STAB 13 reference current adjustment SWT 14 switch-over timing adjustment VA 15 V

voltage adjustment

IDT 16 idle mode timing adjustment PD 17 power-down input MICGND 18 ground reference for the

microphone ampliﬁer MUTET 19 transmit channel mute input MOUT 20 microphone ampliﬁer output GAT 21 microphone gain adjustment MIC 22 microphone input RNOI 23 receive noise envelope timing

adjustment RENV 24 receive signal envelope timing

adjustment RSEN 25 receive signal envelope sensitivity

adjustment TNOI 26 transmit noise envelope timing

adjustment TENV 27 transmit signal envelope timing

adjustment TSEN 28 transmit signal envelope

sensitivity adjustment

handbook, halfpage

DLC/MUTER

1 2

RIN1

RIN2

LSP2

GAR

LSP1

SREF

TEA1093

GND

SUP

VOL

SWR

STAB

SWT

MGD217

Fig.2 Pin configuration.

28 27 26 25 24 23 22 21 20 19 18 17 16 15

TSEN TENV TNOI RSEN RENV RNOI MIC GAT MOUT MUTET MICGND PD IDT VA

1996 Feb 09 5

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

FUNCTIONAL DESCRIPTION

The values given in the functional description are typical values except when otherwise specified.

A principle diagram of the TEA106X is shown on the left side of Fig.3. The TEA106X is a transmission circuit of the TEA1060 family intended for hand-set operation. It incorporates a receiving amplifier for the earpiece, a transmit amplifier for the microphone and a hybrid. For more details on the TEA1060 family, please refer to

Handbook IC03”

. The right side of Fig.3 shows a principle

“Data

diagram of the TEA1093, a hands-free add-on circuit with a microphone amplifier, a loudspeaker amplifier and a duplex controller.

As can be seen from Fig.3, a loop is formed via the sidetone network in the transmission circuit and the acoustic coupling between loudspeaker and microphone of the hands-free circuit. When this loop gain is greater than 1, howling is introduced. In a full duplex application,

this would be the case. The loop-gain has to be much lower than 1 and therefore has to be decreased to avoid howling. This is achieved by the duplex controller.The duplex controller of the TEA1093 detects which channel has the ‘largest’ signal and then controls the gain of the microphone amplifier and the loudspeaker amplifier so that the sum of the gains remains constant. As a result, the circuit can be in three stable modes:

1. Transmit mode (Tx mode): the gain of the microphone amplifier is at its maximum and the gain of the loudspeaker amplifier is at its minimum.

2. Receive mode (Rx mode): the gain of the loudspeaker amplifier is at its maximum and the gain of the microphone amplifier is at its minimum.

3. Idle mode: the gain of the amplifiers is halfway between their maximum and minimum value.

The difference between the maximum gain and minimum gain is called the switching range.

handbook, full pagewidth

telephone

line

HYBRID

sidetone

TEA106X TEA1093

DUPLEX

CONTROL

Fig.3 Hands-free telephone set principles.

acoustic coupling

MGD218

1996 Feb 09 6

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

Supply: pins SUP, SREF, VBB, GND, VA and PD

As can be seen from Fig.4, the line current is divided between the speech-transmission circuit (I the TEA1093 circuit (I

SUP=Iline

− ITR− I

). It can be shown that:

SUP

TR+ICC

) and

Where:

ITR=V V

SUP

SREF

SUP

− V

SREF

= 100 Ω

− V

SREF/RSREF

= 315 mV

ICC≈ 1mA It follows that I

SUP

≈ I

LINE

− 4 mA.

The TEA1093 stabilizes its own supply voltage of 3.6 V at VBB. The voltage on VBB can be adjusted by means of an external resistor RVA.

handbook, full pagewidth

line

SUP

SREF

100 Ω

ITR ICC

SUP

315 mV

V V

SREF

TR1

SWITCH

When R

is connected between pin VA and GND, the

voltage on VBB is increased, when connected between pin VA and VBB, it is decreased. This is shown in Fig.5. Two capacitors of 4.7 nF (C to ensure stability of the supply block. When V greater than VBB+ 0.4 V, the current I VBB via TR1. When V

is less, the current is shunted to

SUP

SREF

and C

) are required

STAB

is supplied to

SUP

GND via TR2, which prevents distortion on the line. To reduce current consumption during pulse dialling or

register recall (flash), the TEA1093 is provided with a power-down (PD) input. When the voltage on PD is HIGH, the current consumption from SUP is 55 µA and from VBB400 µA. Therefore a capacitor of 470 µF (C

VBB

sufficient to power the TEA1093 during pulse dialling.

STAB

4.7 nF V

TR2

to dynamic

limiter

VOLTAGE

STABILIZER

POWER

DOWN

VBB

470 µF

) is

line

TEA1093

TEA106X

SLPE

SREF

4.7 nF

Fig.4 Supply arrangement.

1996 Feb 09 7

GND

MGD219

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

Microphone channel: pin MIC, GAT, MOUT, MICGND and MUTET

handbook, halfpage

(V)

3.6 V without RVA

11010

RVA(VA-GND)

RVA(VA-VBB)

2103

RVA (kΩ)

Fig.5 VBB as a function of RVA.

MGD220

The TEA1093 has an asymmetrical microphone input MIC with an input resistance of 20 kΩ. The gain of the input stage varies according to the mode of the TEA1093. In the transmit mode, the gain is at its maximum; in the receive mode, it is at its minimum and in the idle mode, it is halfway between maximum and minimum. Switch-over from one mode to the other is smooth and click-free. The output capability at pin MOUT is 20 µA (RMS).

In the transmit mode, the overall gain of the microphone amplifier (from pin MIC to MOUT) can be adjusted from 5 dB up to 25 dB to suit specific application requirements. The gain is proportional to the value of R 15 dB typical with R

= 30.1 kΩ.

GAT

A capacitor must be connected in parallel with R

and equals

GAT

to ensure stability of the microphone amplifier. Together with R

, it also provides a first-order low-pass filter.

GAT

By applying a HIGH level on pin MUTET, the microphone amplifier is muted and the TEA1093 is automatically forced into the receive mode.

handbook, full pagewidth

MIC

MUTET

MIC

envelope

detector

V I I V

from voice switch

logic

GAT 21

MOUT

MICGND

MGD221

GAT

to TEA106X

Fig.6 Microphone channel.

1996 Feb 09 8

Philips Semiconductors Product speciﬁcation

Hands-free IC TEA1093

handbook, full pagewidth

GAR

LSP1

DLC

GAR

LSP1

DLC/MUTER

LSP2

from voltage

stabilizer

DYNAMIC

LIMITER

−1

Fig.7 Loudspeaker channel.

Loudspeaker channel

OUDSPEAKER AMPLIFIER: PINS RIN1, RIN2, GAR, LSP1

AND LSP2

The TEA1093 has symmetrical inputs for the loudspeaker amplifier with an input resistance of 40 kΩ between RIN1 and RIN2 (2 × 20 kΩ). The input stage can accommodate signals up to 390 mV (RMS) at room temperature for 2% of total harmonic distortion (THD). The gain of the input stage varies according to the mode of the TEA1093. In the receive mode, the gain is at its maximum; in the transmit mode, it is at its minimum and in the idle mode, it is halfway between maximum and minimum. Switch-over from one mode to the other is smooth and click-free. The rail-to-rail output stage is designed to power a loudspeaker which is connected as a single-ended load (between LSP1 and GND) or as a bridge-tied load (between LSP1 and LSP2).

In the receive mode, the overall gain of the loudspeaker amplifier can be adjusted from 3 dB up to 39 dB to suit specific application requirements. The gain from RIN1 or RIN2 to LSP1 is proportional to the value of R equals 18 dB with R

= 66.5 kΩ. The second output

GAR

and

LSP2 is in opposite phase with LSP1. Therefore, in the basic application, the gain between RIN1-RIN2 to LSP1-LSP2 equals 24 dB typical with R A capacitor connected in parallel with R

= 66.5 kΩ.

GAR

can be used to

GAR

provide a first-order low-pass filter.

I V

envelope

detector

RIN1 2

RIN2

VOL

MGD222

from TEA106X

VOL

to/from

logic

voice switch

V I

VOLUME

CONTROL

OLUME CONTROL: PIN VOL

The loudspeaker amplifier gain can be adjusted with the potentiometer R

. A linear potentiometer can be used to

VOL

obtain logarithmic control of the gain at the loudspeaker amplifier. Each 950 Ω increase of R

results in a gain

VOL

loss of 3 dB. The maximum gain reduction with the volume control is internally limited to the switching range.

YNAMIC LIMITER: PIN DLC/MUTER

The dynamic limiter of the TEA1093 prevents clipping of the loudspeaker output stages and protects the operation of the circuit when the supply condition falls below a certain level.

Hard clipping of the loudspeaker output stages is prevented by rapidly reducing the gain when the output stages start to saturate. The time in which gain reduction is effected (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 (typical 250 ms). Both attack and release times are proportional to the value of the capacitor C

. The total

DLC

harmonic distortion of the loudspeaker output stages, in reduced gain mode, stays below 5% up to 10 dB (minimum) of input voltage overdrive [providing V

RIN

below 390 mV (RMS)].

1996 Feb 09 9

+ 19 hidden pages