L3234 Просмотр технического описания (PDF) - STMicroelectronics

Номер в каталоге

Компоненты Описание

производитель

L3234

HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS

STMicroelectronics 

L3234 - L3235

OPERATION DESCRIPTION

The Fig. 3 show the simplified circuit configuration

of the L3234 Solid State Ringing injector when

used with the L3235 Line Feeder.

Figure 3: L3234/L3235 Circuit Configuration

+100V GND +5V

C100 CVCC

A

TIP

LINE TERMINALS

B

RING

CO1

CO2

RO1

RO2

V100 GND VCC

OUT1

6

4

3

5

RINGING INJECTOR

7

OUT2

L3234

LINE FEEDER

L3235

CS

CS

GND

-VBAT

2

1

VA

CA

D94TL132

VA

EXTERNAL COMPONENTS LIST

In the following table are shown the recommended external components values for L3234.

Ref.

R01, R02

C01, C02

CA

C100

CVCC

Value

82Ω

10µF - 160V

4.7µF - 10V

100nF - 100V

100nF

Involved Parameter or Function

Ringing Feeding Series Resistors

Ringing Feeding De coupling Capacitors

Low Level Ringing Signal De coupling Capacitor

Positive Battery Filter

+5V Supply Filter

When the ringing function is selected by the sub-

scriber card, a low level signal is continuously ap-

plied to pin 1 through a de coupling capacitor. Then

the logical ring drive signal CS provided by L3235 is

applied to pin 2 with a cadenced mode.

The ringing cycles are synchronised by the L3234

in such a way that the ringing starts and stops al-

ways when the analog input signal crosses zero.

When the ringing injection is enabled (CS = "1"),

an AC ringing signal is injected in a balanced

mode into the telephone line.

When the ringing injection is disabled (CS = "0"),

the output voltage on OUT2 raises to the high

power supply, whereas on OUT1, it falls down to

ground.

The L3234 has a low output impedance when

sending the signal, and high output impedance

when the ringing signal is disabled

In fig. 4 the dynamic features of L3234 are

shown.

6/26

Share Link: