PBL38650/2QNT Infineon Technologies, PBL38650/2QNT Datasheet - Page 42

• Manufacturer Part Number: PBL38650/2QNT
• Description: IC LINE INTERFACE SLIC PLCC-28
• Manufacturer: Infineon Technologies
• Series: FlexiSLIC™r

Specifications of PBL38650/2QNT

• 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: PBL38650/2QNTT; SP000007905

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 9
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.
Complete filtering of the 20 Hz AC component at terminal DT and DR is not necessary.
A toggling DET output can be examined by a software routine to determine the duty
cycle. When the DET output is at logic level low for more than half the time, off-hook
conditions is indicated.
8
The PBL 38650/2 SLIC incorporates a ring relay driver designed as open collector (npn),
with a current sinking capability of 50 mA. The drive transistor emitter is connected to
BGND. The relay driver has an internal zener diode clamp for inductive kick back
voltages.
9
The SLIC has three digital control inputs, C1, C2 and C3 (see
SLIC interprets the control input condition and sets up the commanded operating state.
C1, C2 and C3 are internally pulled up.
9.1
In the Open Circuit state, the TIPX and RINGX line drive amplifiers as well as other circuit
blocks are powered down. This causes the SLIC to present a high impedance to the line.
Power dissipation is at a minimum and no detectors are active. DET output is set high.
Data Sheet
RT
and will cause input DT to become more negative than input DR. This changes
gives an example of a ring trip detector network. This network is applicable
Relay Driver
Control Inputs
Open Circuit (C3, C2, C1 = 0, 0, 0)
V
42
B
and is injected on the ring lead of the two-
R
1
,
R
2
,
R
R
3
RT
,
R
is monitored by the ring trip
4
,
C
1
Table
and
C
2). A decoder in the
Rev. 2.0, 2005-04-14
2
.
PBL 38650/2
Relay Driver
FlexiSLIC