TEA1064AT View Datasheet(PDF) - Philips Electronics

Part Name

Description

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TEA1064AT

Low voltage versatile telephone transmission circuit with dialler interface and transmit level dynamic limiting

Philips Electronics 

Philips Semiconductors

Low voltage versatile telephone transmission circuit

with dialler interface and transmit level dynamic limiting

Product specification

TEA1064A

FUNCTIONAL DESCRIPTION

Supplies VCC1, VCC2, LN, SLPE, REG and STAB (Fig.3)

Power for the TEA1064A and its peripheral circuits is

usually obtained from the telephone line. The IC develops

its own supply voltage at VCC1 and regulates its voltage

drop. The internal supply requires a decoupling capacitor

between VCC1 and VEE. The internal current stabilizer is

set by a 3.6 kΩ resistor between STAB and VEE.

The DC current flowing into the set is determined by the

exchange supply voltage Vexch, the feeding bridge

resistance Rexch, the subscriber line DC resistance Rline

and the DC voltage (including polarity guard) on the

subscriber set (see Fig.3).

The internal voltage regulator generates a

temperature-compensated reference voltage that is

available between VCC2 and SLPE

[Vref = VCC2-SLPE = 3.3 V (typ.)]. This internal voltage

regulator requires decoupling by a capacitor between REG

and VEE (C3).

The reference voltage can be used to:

• regulate directly the line voltage (stabilized

VLN-SLPE = VCC2-SLPE)(1)

• to stabilize the supply voltage for peripherals.

Regulated line voltage

In this application the VCC2 pin is connected to the LN pin

as shown in Fig.3. This configuration gives a stabilized

voltage across pins LN and SLPE which, applied via the

low-pass filter R16, C15, provides a supply to the

peripherals that is independent of the line current and

depends only on the peripheral supply current.

The value of R16 and the level of the DC voltage VLN-SLPE

determine the supply capabilities. In the basic application

R16 = 392 Ω and C15 = 220 µF. The worst-case

peripheral supply current as a function of supply voltage is

shown in Fig.4. To increase the supply capabilities, the DC

voltage VLN-SLPE can be increased by using RVA(REG-SLPE)

or by decreasing the value of R16.

(1) The TEA1064A application with regulated line voltage is the

same as is used for TEA1060/TEA1061, TEA1067 and

TEA1068 integrated circuits.

handbook, full pagewidth

Rexch

Vexch

Rline

Iline

Ip + 0.25 mA

R1

TEA1064A

ISLPE

ICC1

LN

VCC1

1

16

19

VCC2

DC

AC

17

10

REG STAB

C3

R5

20

SLPE

R9

0.25 mA

11

VEE

C1 R16

Ip

C15

peripheral

circuits

Vp

The voltage VLN-SLPE is fixed to Vref = 3.3 ± 0.25 V. Resistor R16 together with the

line current determine the supply capabilities and the maximum output swing on

the line (no loop damping is necessary).

The line voltage VLN = Vref + ([Iline − 1.55 mA] × R9).

MGR058

Fig.3 Application with regulated line voltage (stabilized VLN-SLPE).

March 1994

6

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