STLC3080 datasheet(5/23 Pages) STMICROELECTRONICS

5 / 23 page

Resistive Region is programmable by means of

external resistor RDC, limiting current can be se-

lected by RLIM resistor.

Concerning AC characteristic the STLC3080 allows

to set 2W termination impedance by means of one

external scaled impedance that may be complex.

Two to four wire conversion is provided by an exter-

nal network. Such network can be avoided in case

of application with COMBOII, in this case the two to

four wire conversion is implemented inside the

COMBOII by means of the programmable Hybal fil-

ter.

When in ACTIVE mode it is also possible to per-

form battery reversal in soft mode (with program-

mable transition time) without affecting the AC sig-

nal transmission.

Ringing

When Ringing mode is selected the STLC3080

activates the ring relay injecting the ringing signal

on the line. As the ring trip is detected the logic in-

dicator DET is set low and the ringing is automat-

ically disconnected without waiting for the card

controller command (auto ring trip).

DET remains latched Low untill the operative

mode is modified.

If required , the ringing relay drive signal RELR

can be synchronised to a clock applied to

CKRING input.

This clock is derived from the ringing signal with

proper time delay, according to the activation/de-

activation time of the relay.

RELR is activated on the low level of CKRING

clock. The duty cycle of CKRING can be modified

in order to activate the RELR when required:

CKRING low must last 1

µs minimum.

If the synchronisation is not required, CKRING in-

put must be steadily kept Low.

All the STLC3080 relay drivers are open drain

with the source connected to the RGND pin. Each

relay drivers integrates a protection structure that

allows to avoid external kick - back diodes, using

both 5V or 12V relays.

The ring trip circuit and its behaviour is described

in Appendix D.

Ground Start.

This mode is selected when the SLIC is adopted

in a system using the Ground Start feature. In this

mode the TIP termination is set in High Imped-

ance (100k

Ω) while the RING one is active and

fixed at Vbat +4.8V. In the case of connection of

RING termination to GND the sinked current is

limited to 30mA. When RING is connected to

GND both Off-Hook and Ground-Key detectors

become active. Power dissipation in this mode

with a -48V battery voltage is 100mW

High Impedance Feeding.

As Stand-By, this mode is set in On-Hook condi-

tion, with further reduced power consumption.

Higher power efficiency turns back a lower immu-

nity of the Off-Hook detector to line common

mode currents.

The DC feeding shows a constant current charac-

teristic (Ilim = 17mA) followed by a resistive range

with an equivalent series resistance RFEED =

1600

Ω + 2Rp.

Thermal protection circuit is still active, preventing

the junction temperature, in case of fault condi-

tion, to exceed 150

°C

In High Impedance Feeding most of the circuit is

switched off, only the circuit, dedicated to Off-

Hook detection, is powered. This allows to reduce

the total power consumption in On-hook to 30mW

(typical).

The Off-Hook detection threshold is not program-

mable but defined at a fixed IDETHI = 8mA(max.)

ILIM [20÷50mA]

RFEED =

RDC

+2RP

RFEED =2RP

VBAT

VBAT -7.8V

Figure b. STLC3080 DC Characteristic in

Active Mode.

17mA

RFEED = 1600Ω +2RP

D98TL373

VBAT -0.8V

Figure c. STLC3080 DC Characteristic in High

Impedance Feeding

STLC3080

5/23

STLC3080 数据表(PDF) 5 Page - STMicroelectronics

STLC3080 数据表(HTML) 5 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

数据表下载