
March 1994
5
Philips Semiconductors
Product specification
Call progress monitor for line powered
telephone sets
TEA1083; TEA1083A
Table 1
Comparison of the TEA108X family.
PRODUCT
CONDITIONS
TEA1083
TEA1083A
TEA1085/85A
Application area
PD facility
MUTE or LSE facility
Dynamic limiter
Howling limiter
V
BB
setting
SEL
BTL
Number of pins
note 1
call progress monitoring
X
X
8
listening-in
X
X
X
X
X
X
X
24
X
X
X
16
note 2
note 3
note 3
note 4
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
)), 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) (P
O
≥
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)
(P
O
≈
20 mW).
The MUTE function of the TEA1085A has a logic input;
the MUTE function of the TEA1085 has a toggle input.
SEL: loudspeaker connected in a single-ended-load
configuration
BTL: loudspeaker connected in a bridge-tied-load
configuration
Consult the product specification for the package
outline/s.
2.
3.
4.
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
BB
and V
SS
In Fig.6 the line current is divided into I
TR
for the
transmission IC and I
SUP
for the monitoring circuit
TEA1083/83A.
I
TR
is constant:
I
TR
= V
int
/ R20
I
SUP
= I
line
I
CC
I
TR
Where:
V
int
is an internal temperature compensated reference
voltage of 500 mV (typ) between pins SUP and SREF
R20 is a resistor connected between SUP and SREF
I
CC
is the internal current consumption of the TEA106X
(approximately 1 mA).
A practical value for resistor R20 is 150
; this produces a
current of approximately 3.3 mA (typ) for I
TR
and I
SUP
is
approximately equal to I
line
4.3 mA.