PBL38630/2QNT Infineon Technologies, PBL38630/2QNT Datasheet - Page 41

• Manufacturer Part Number: PBL38630/2QNT
• Description: IC LINE INTERFACE SLIC PLCC-28
• Manufacturer: Infineon Technologies
• Series: FlexiSLIC™r

Specifications of PBL38630/2QNT

• Function: Subscriber Line Interface Concept (SLIC)
• Number Of Circuits: 1
• Voltage - Supply: 5V
• Current - Supply: 2.8mA
• Power (watts): 730mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-PLCC
• Includes: Current Feeding, Ground Key Detector, Ring Relay Driver
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Interface: -
• Other names: PBL38630/2QNTT; SP000007897

7
The loop current, ground key and ring-trip detectors report their status through a
common output, DET. The particular detector to be connected to the detector pin, DET,
is selected via the two bit control interface C1and C2. Please refer to Chapter 9 for a
description of the control interface.
7.1
The loop current detector indicates that the telephone is off-hook and that DC current is
flowing in the loop by setting the output pin DET to a logic low level when selected. The
loop current detector threshold value,
state, is programmable with the
and is calculated according to:
The loop current detector is internally filtered and is not influenced by the AC signal at
the two-wire side.
7.2
Ring trip detection is accomplished by connecting an external network to a comparator
in the SLIC with inputs DT and DR. The ringing source can be balanced or unbalanced
superimposed on
the ring lead or the tip lead with return via the other wire. A ring relay driven by the SLIC
ring relay driver connects the ringing source to tip and ring.
The ring trip function is based on a polarity change at the comparator input when the line
goes off-hook. In the on-hook state no DC current flows through the loop and the voltage
at comparator input DT is more positive than the voltage at input DR. When the line goes
off-hook, while the ring relay is energized, DC current flows and the comparator input
voltage reverses polarity.
Figure 8
when the ring voltage is superimposed on
wire port. The DC voltage across sense resistor
comparator input DT and DR via the network
When the line is on-hook (no DC current), DT is more positive than DR and the DET
output will report logic level high, that is the detector is not tripped. When the line goes
off-hook, while ringing, a DC current will flow through the loop including sense resistor
R
output DET to logic level low, that is tripped detector conditions. The system controller
(or line card processor) responds by de-energizing the ring relay, that is ring trip.
Data Sheet
R
RT
LD
and will cause input DT to become more negative than input DR. This changes
=
500
--------- -
I
Lth
gives an example of a ring trip detector network. This network is applicable
Loop Monitoring Functions
Loop Current Detector
Ring Trip Detector
V
B
or GND. The unbalanced ringing source may be applied to either
R
LD
resistor.
I
LTh
V
41
, where the loop current detector changes
B
R
and is injected on the ring lead of the two-
R
LD
1
,
connects between pin PLD and ground
R
2
,
R
R
3
RT
,
R
is monitored by the ring trip
4
Loop Monitoring Functions
,
C
1
and
C
Rev. 2.0, 2005-04-14
2
.
PBL 38630/2
FlexiSLIC
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