Philips TEA1111AT Datasheet

INTEGRATED CIRCUITS

DATA SH EET

TEA1111A

Speech circuit with dialler interface,
regulated supply and earpiece
volume control

Product specification
Supersedes data of 1999 Sep 28
File under Integrated Circuits, IC03

1999 Nov 22

Philips Semiconductors Product specification

Speech circuit with dialler interface, regulated
supply and earpiece volume control

FEATURES

• Low DC linevoltage; operates down to 1.5 V (excluding
voltage drop across external polarity guard)

• Line voltage regulator with adjustable DC voltage

• 3.25 V regulated strong supply point for peripheral

circuits compatible with:
– Speech mode
– Ringer mode
– Trickle mode.

• Transmit stage with:
– Microphone amplifier with symmetrical high

impedance inputs

– DTMF amplifier with confidence tone on earpiece.

• Receive stage with:
– Earpiece amplifier with adjustable gain and volume

control.

• MUTE input for pulse or DTMF dialling

• AGC line loss compensation for microphone and

earpiece

• LED control output.

APPLICATIONS

• Line powered telephone sets with LCD module

• Cordless telephones

• Fax machines

• Answering machines.

GENERAL DESCRIPTION

The TEA1111A is a bipolar integrated circuit that performs
all speech and line interface functions required in fully
electronic telephone sets. It performs electronic switching
between speech and dialling. The IC operates at a line
voltage down to 1.5 V DC (with reduced performance) to
facilitate the use of telephone sets connected in parallel.

When the line current is high enough, a fixed amount of
current is derived from the LN pin in order to create a
strong supply point at pin VDD. The voltage at pin VDD is
regulated to 3.25 V to supply peripherals such as dialler,
LCD module and microcontroller.

TEA1111A

QUICK REFERENCE DATA

I

= 15 mA; VEE=0V; V

line

according to test circuits given in Figs 14, 15 and 16; T

VCI

=0V; R

=20Ω; AGC pin connected to VEE; Z

SLPE

=25°C; unless otherwise specified.

amb

= 600 Ω; f = 1 kHz; measured

line

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

I

line

line current operating range normal operation 11 − 140 mA

with reduced

1 − 11 mA

performance

V

LN

I

CC

V

CC

V

DD

I

DD

G

v(TX)

G

v(QR)

∆G

v(QR)

∆G

v(trx)

∆G

v(trx)(m)

DC line voltage 3.7 4.0 4.3 V
internal current consumption VCC= 3.3 V − 1.15 1.4 mA
supply voltage for internal circuitry (unregulated) IP=0mA − 3.3 − V
regulated supply voltage for peripherals

speech mode I
ringer mode I

= −3 mA 2.95 3.25 3.55 V

DD

= 75 mA 3.0 3.3 3.6 V

DD

available supply current for peripherals −−−3mA
typical voltage gain for microphone amplifier V

= 4 mV (RMS) 43.2 44.2 45.2 dB

MIC

typical voltage gain for earpiece amplifier VIR= 4 mV (RMS) 26.4 27.4 28.4 dB
volume control range for earpiece amplifier 0 14.5 − dB
gain control range for microphone and earpiece

amplifiers with respect to I

=15mA

line

gain reduction for microphone and earpiece

I

=85mA − 6.0 − dB

line

MUTE = LOW − 80 − dB

amplifiers

1999 Nov 22 2

Philips Semiconductors Product specification

Speech circuit withdialler interface,regulated

TEA1111A

supply and earpiece volume control

ORDERING INFORMATION

TYPE

NUMBER

NAME DESCRIPTION VERSION

TEA1111AT SO16 plastic small outline package; 16 leads; body width 3.9 mm SOT109-1

BLOCK DIAGRAM

handbook, full pagewidth

receive

amplifier

VI

MUTE

4

IR

8

PACKAGE

VOLUME

CONTROL

GARVCI

129

earpiece
amplifier

11

QR

DTMF

MIC+
MIC−

V

EE

AGC

6

ATTENUATOR

13
14

microphone

amplifier

10

5

VI

VI

VI

TEA1111A

AGC

CIRCUIT

0.5V

CC

CURRENT AND

VOLTAGE

REFERENCE

V

DD

REGULATOR

LOW VOLTAGE

CIRCUIT

LED CONTROL

153

16

V

CC

7

V

DD

1

LN

2

FCA051

Fig.1 Block diagram.

1999 Nov 22 3

SLPELEDCREG

Philips Semiconductors Product specification

Speech circuit withdialler interface,regulated
supply and earpiece volume control

PINNING

SYMBOL PIN DESCRIPTION

LN 1 positive line terminal
SLPE 2 slope (DC resistance) adjustment
REG 3 line voltage regulator decoupling
IR 4 receive amplifier input
AGC 5 automatic gain control/

line loss compensation
DTMF 6 dual-tone multi-frequency input
V

DD

7 regulated supply for peripherals

MUTE 8 mute input to select speech or

dialling mode (active LOW)
VCI 9 volume control input
V

EE

10 negative line terminal
QR 11 earpiece amplifier output
GAR 12 earpiece amplifier gain adjustment
MIC+ 13 non-inverting microphone amplifier

input
MIC− 14 inverting microphone amplifier input
LEDC 15 LED control output
V

CC

16 supply voltage for internal circuit

handbook, halfpage

LN

1

SLPE

2
3

REG

IR

4

TEA1111A

5

AGC

DTMF

6

V

7

DD

8

MUTE

FCA052

Fig.2 Pin configuration.

TEA1111A

V

16

CC

LEDC

15
14

MIC−

13

MIC+

12

GAR

11

QR
V

10

EE

VCI

9

FUNCTIONAL DESCRIPTION

All data given in this chapter concerns typical values,
except when otherwise specified.

Supply (pins LN, SLPE, REG, VCCand VDD)

The supply for the TEA1111A and its peripherals is
obtained from the telephone line (see Fig.3).

HE LINE INTERFACE (PINS LN, SLPE AND REG)

T
The IC generates a stabilized reference voltage (V

across pins LN and SLPE. V

is temperature

ref

ref

)

compensated and can be adjusted by using an external
resistor (RVA). V

equals 3.8 V and can be increased by

ref

connecting RVA between pins REG and SLPE or
decreased by connecting R

between pins REG and LN.

VA

The voltage at pin REG is used by the internal regulator to
generate V

and is decoupled by C

ref

, which is

REG

connected to VEE. This capacitor, converted to an
equivalent inductance, (see Section “Set impedance”)
determines the set impedance conversion from its DC
value (R

) to its AC value (RCCin the audio-frequency

SLPE

range). The voltage at pin SLPE is proportional to the line
current.

The voltage at pin LN is:
V

LN=Vref+RSLPE

I

SLPE=Iline

− ICC− IP− I

× I

SLPE

SUP

− I

LEDC

where:

I

= line current

line

ICC= current consumption of the IC
IP= supply current for external circuits
I

= current consumed between LN and VEE by the

SUP

VDD regulator
I

= supply current for external LED circuitry.

LEDC

Thepreferredvaluefor R

is 20 Ω.ChangingR

SLPE

SLPE

will
affect more than the DC characteristics; it also influences
the microphone and DTMF gains, the gain control
characteristics, the sidetone level and the maximum
output swing on the line.

The DC line current flowing into the set is determined by
the exchange supply voltage (V
resistance (R
line (R

) and the reference voltage (V

line

currents below I
(generatingV

), the DC resistance of the telephone

EXCH

(9 mA), the internal reference voltage

low

)isautomaticallyadjusted to a lower value.

ref

), the feeding bridge

EXCH

). With line

ref

1999 Nov 22 4

Philips Semiconductors Product specification

Speech circuit withdialler interface,regulated
supply and earpiece volume control

This means that several sets can operate in parallel with
DC line voltages (excluding the polarity guard) down to an
absolute minimum voltage of 1.5 V. At line currents below
I

, the circuit has limited sending and receiving levels.

low

This is called the low voltage area.

THE INTERNAL SUPPLY POINT (PIN VCC)
The internal circuitry of the TEA1111A is supplied from

pin V

. This voltage supply is derived from the line

CC

voltage by means of a resistor (RCC) and must be
decoupled by a capacitor C

. It may also be used to

VCC

supply some external circuits.

The V
current consumed by the IC and the peripheral circuits as:

V

CC0=VLN

VCC=V
Where I

the earpiece amplifier.

TEA1111A

voltage (see also Figs 4 and 5) depends on the

CC

− RCC× I

− RCC× (IP+I

CC0

is the current consumed by the output stage of

rec

CC

rec

)

handbook, full pagewidth

LED

CIRCUIT

R

EXCH

V

EXCH

R

line

LEDC

CONTROL

LED

I

SLPE

I

LEDC

R

20 Ω

SLPE

I

line

from preamplifier

I

LN

LN

I

SUP

REGSLPE

C

4.7 µF

R

CC

V

DD

REGULATOR

V

REG

internal

circuitry

TEA1111A

EE

I

CC

V

V

CC

DD

I

DD

peripherals

C

VCC

100 µF

C

VDD

220 µF

external

circuits

FCA053

I

P

Fig.3 Supply configuration.

1999 Nov 22 5

Philips Semiconductors Product specification

Speech circuit with dialler interface, regulated
supply and earpiece volume control

V

R

CC0

handbook, halfpage

Fig.4 VCC used as supply voltage for external circuits.

CC

V

CC

I

rec

V

EE

EXTERNAL

CIRCUITS

I

P

MGK806

TEA1111A

handbook, halfpage

VCC≥ 2.2 V; VLN= 4 V at I
(1) Curve 1 is valid when the earpiece amplifier is driven: V
(2) Curve 2 is valid when the earpiece amplifier is not loaded.

= 15 mA; RCC= 619 Ω; R

line

2

I

P

(mA)

1.6

1.2

0.8

0.4

0

2.2 2.6 3.4

SLPE

(1) (2)

=20Ω.

= 150 mV; RL= 150 Ω.

QR(rms)

3.0

FCA054

VCC (V)

Fig.5 Typical current IP available from VCC for peripheral circuitry.

1999 Nov 22 6

Philips Semiconductors Product specification

Speech circuit with dialler interface, regulated
supply and earpiece volume control

THE REGULATED SUPPLY POINT (PIN VDD)
The V

regulator delivers a stabilized voltage for the

DD

peripherals in transmission mode (nominal VLN) as well as
in ringer mode (VLN= 0 V). The regulator (see Fig.6)
consists of a sense input circuit fed by pin LN, a current
switch and a V

output stabilizer.

DD

Theregulatorfunctiondependsonthetransmission,ringer
and trickle modes as follows:

• Transmissionmode:Theregulatoroperatesasacurrent
source at the LN input; it takes a constant current of

= 4.3 mA (at nominal conditions) from pin LN.

I

SUP

The current switch reduces the distortion on the line at
large signal swings. Output V

follows the DC voltage

DD

at pin LN (with typically 0.35 V difference) up to
VDD= 3.25 V. The input current of the regulator is
constant while the output (source) current is determined
by the consumption of the peripherals. The difference
between input and output currents is shunted by the
internal VDD stabilizer.

• Ringer mode: The regulator operates as a shunt

• Trickle mode: When VDD is below 2 V, the regulator is

TEA1111A

stabilizer to keep V
VLNequals 0 V while the input current into pin VDD is
delivered by the ringingsignal. VDDhas to be decoupled
by a capacitor C

inhibited. The current consumption of the VDDregulator
in trickle mode is very low to save most of the trickle
current for memory retention of a dialler.

at 3.3 V. The input voltage

DD

.

VDD

handbook, full pagewidth

R

EXCH

V

EXCH

R

line

TEA1111A

I

line

LN

I

SUP

R

CC

I

LN

SENSE

I

CC

V

CC

SWITCH

VDD regulator

V

EE

C

V

DD

I

DD

peripherals

C

VDD

220 µF

FCA055

VCC

100 µF

Fig.6 VDD regulator configuration.

1999 Nov 22 7

Philips Semiconductors Product specification

Speech circuit with dialler interface, regulated
supply and earpiece volume control

LED control (pin LEDC)

The TEA1111A gives an on-hook/off-hook status
indication. This is achieved by a current made available at
pin LEDC to drive an external LED circuit connected
between pins SLPE and LN (see Fig.7). In the low voltage
area, which corresponds to low line current conditions, no
current is available for this LED. For line currents higher
than a threshold, the LEDC current increases
proportionally to the line current (with a ratio of 1:150).
The LEDC current is internally limited to 470 µA
(see Fig.8).

I

12–

For 12 mA < I

< 82 mA:

line

I

LEDC

This LED circuit is referenced to SLPE. Consequently, all
theLEDsupply current will flow through the R
and does not affect the behaviour of the AGC.

Set impedance

line

=

--------------------­150

SLPE

resistor,

BC858B

TEA1111A

LN

24

Ω

2.4
kΩ

LEDC

SLPE

FCA056

In the audio frequency range, the dynamic impedance is
mainly determined by the RCC resistor. The equivalent
impedance of the circuit is illustrated in Fig.9.

500

handbook, halfpage

I

LEDC

(µA)

400

300

200

100

FCA057

handbook, halfpage

Fig.7 LED circuit configuration.

LN

R

CC

619 Ω

CC

C

VCC

100 µF

MBE788

V

EE

SLPE

L

EQ

V

R

SLPE

20 Ω

ref

R

P

REG V

C

REG

4.7 µF

0

0 20 40 100

60 80

I

line

(mA)

Fig.8 LEDC current versus line current.

1999 Nov 22 8

LEQ=C
RP= internal resistance.
RP= 17.5 kΩ.

REG

× R

SLPE

× RP.

Fig.9 Equivalent impedance between LN and VEE.