tea1114auh NXP Semiconductors, tea1114auh Datasheet - Page 6

• Manufacturer Part Number: tea1114auh
• Description: Low Voltage Telephone Transmission Circuit With Dialler Interface And Regulated Strong Supply
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION
All data given in this chapter are typical values, except
when otherwise specified.
Supply (pins LN, SLPE, REG, V
The supply for the TEA1114A and its peripherals is
obtained from the telephone line (see Fig.3).
T
The IC generates a stabilized reference voltage (V
between pins LN and SLPE. V
compensated and can be adjusted by means of an
external resistor (R
increased by connecting R
SLPE or decreased by connecting R
REG and LN. The voltage at pin REG is used by the
internal regulator to generate V
C
converted into an equivalent inductance
(see Section “Set impedance”) realizes the set impedance
conversion from its DC value (R
(R
pin SLPE is proportional to the line current.
The voltage at pin LN is:
2000 Mar 21
V
handbook, full pagewidth
HE LINE INTERFACE
REG
LN
CC
Low voltage telephone transmission circuit with
dialler interface and regulated strong supply
=
, which is connected to V
V EXCH
in the audio-frequency range). The voltage at
R EXCH
V
ref
+
R
SLPE
VA
R line
(
PINS
TEA1114A
). V
I
SLPE
REG
C REG
ref
4.7 F
from preamplifier
LN, SLPE
VA
equals 4.15 V and can be
between pins REG and
EE
ref
ref
SLPE
. This capacitor,
is temperature
CC
and is decoupled by
I line
AND
) to its AC value
and V
VA
between pins
REG)
I SLPE
DD
)
LN
Fig.3 Supply configuration.
SLPE
R SLPE
ref
I LN
20
I SUP
)
REGULATOR
6
V DD
The preferred value for R
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
currents below 9 mA, the internal reference voltage
(generating V
This means that more sets can operate in parallel with
DC line voltages (excluding the polarity guard) down to an
absolute minimum voltage of 1.45 V. At currents below
9 mA, the circuit has limited sending and receiving levels.
This is called the low voltage area.
I
where:
SLPE
R CC
V EE
I
I
I
I
V
line
CC
P
SUP
DD
= supply current for external circuits
= current consumption of the IC
=
= line current
line
regulator.
V CC
= current consumed between LN and V
I
circuitry
internal
line
) and the reference voltage (V
–
EXCH
ref
V DD
I
I CC
CC
) is automatically adjusted to a lower value.
–
), the DC resistance of the telephone
I
P
I DD
peripherals
–
I
SUP
SLPE
is 20 . Changing R
EXCH
C VDD
220 F
C VCC
100 F
), the feeding bridge
Product specification
TEA1114A
ref
). With line
MGK805
external
circuits
EE
by the
SLPE
I P
will