TEA1111AT/C1 Ver la hoja de datos (PDF) - Philips Electronics
Número de pieza
componentes Descripción
Fabricante
TEA1111AT/C1
Philips Electronics
TEA1111AT/C1 Datasheet PDF : 24 Pages
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Philips Semiconductors
Speech circuit with dialler interface, regulated
supply and earpiece volume control
Product specification
TEA1111A
THE REGULATED SUPPLY POINT (PIN VDD)
The VDD regulator delivers a stabilized voltage for the
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 VDD output stabilizer.
The regulator function depends on the transmission, ringer
and trickle modes as follows:
• Transmission mode: The regulator operates as a current
source at the LN input; it takes a constant current of
ISUP = 4.3 mA (at nominal conditions) from pin LN.
The current switch reduces the distortion on the line at
large signal swings. Output VDD follows the DC voltage
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
stabilizer to keep VDD at 3.3 V. The input voltage
VLN equals 0 V while the input current into pin VDD is
delivered by the ringing signal. VDD has to be decoupled
by a capacitor CVDD.
• Trickle mode: When VDD is below 2 V, the regulator is
inhibited. The current consumption of the VDD regulator
in trickle mode is very low to save most of the trickle
current for memory retention of a dialler.
handbook, full pagewidth Rline
Iline
I LN
LN
REXCH
ISUP
VEXCH
TEA1111A
RCC
I CC
VCC
SENSE
SWITCH
VDD regulator
VEE
VDD
IDD
CVCC
100 µF
peripherals
CVDD
220 µF
FCA055
1999 Nov 22
Fig.6 VDD regulator configuration.
7
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