HC5513BIM Intersil, HC5513BIM Datasheet - Page 11

• Manufacturer Part Number: HC5513BIM
• Description: IC SLIC DLC/FLC LP STDBY 22-DIP
• Manufacturer: Intersil
• Series: UniSLIC14r

Specifications of HC5513BIM

• Function: Subscriber Line Interface Concept (SLIC)
• Number Of Circuits: 1
• Current - Supply: 2.25mA
• Power (watts): 1.5W
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 22-DIP (0.400", 10.16mm)
• Includes: Ground Key Detector, Programmable Loop Current Detector, Ring Trip Detector, Thermal Shutdown
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Voltage - Supply: -
• Interface: -

The value of Z
Where V
Therefore:
Example:
Given: R
value), R
The value of Z
Supervisory Functions
The loop current, ground key and the ring trip detector
outputs are multiplexed to a single logic output pin called
DET. See Table 1 to determine the active detector for a given
logic input. For further discussion of the logic circuitry see
section titled “Digital Logic Inputs”.
Before proceeding with an explanation of the loop current
detector, ground key detector and later the longitudinal
impedance, it is important to understand the difference
between a “metallic” and “longitudinal” loop currents. Figure
18 illustrates 3 different types of loop current encountered.
Case 1 illustrates the metallic loop current. The definition of
a metallic loop current is when equal currents flow out of tip
and into ring. Loop current is a metallic current.
Cases 2 and 3 illustrate the longitudinal loop current. The
definition of a longitudinal loop current is a common mode
current, that flows either out of or into tip and ring
simultaneously. Longitudinal currents in the on-hook state
result in equal currents flowing through the sense resistors
R
Z
Z
1
B
B
HC5513
and R
=
=
–
R
R
TX
TX
F
RX
TX
2
•
= 20Ω and Z
(Figure 18). And longitudinal currents in the off-
•
/V
Z
---------- -
= 20kΩ, Z
FIGURE 17. TRANSHYBRID CIRCUIT
Z
V
-----------
V
V
RSN
RX
TX
T
B
RX
TX
B
TX
is then:
= 18.7kΩ.
•
equals 1/ A
------------ -
1000
------------------------------------------- -
Z
Z
T
T
Z
RX
L
+
L
R
+
= 600Ω,
2R
= 280kΩ, Z
TX
2R
Z
RX
F
4-4
F
11
+
Z
I
I
2
.
1
L
Z
B
T
= 562kΩ (standard
R
FB
CODEC/
V
FILTER
+
-
RX
+
-
(EQ. 22)
(EQ. 23)
V
TX
+
-
HC5513
hook state result in unequal currents flowing through the
sense resistors R
longitudinal currents flowing away from the SLIC, the current
through R
current; whereas the current through R
current minus the longitudinal current. Longitudinal currents
are generated when the phone line is influenced by magnetic
fields (e.g., power lines).
Loop Current Detector
Figure 18 shows a simplified schematic of the loop current
and ground key detectors. The loop current detector works
by sensing the metallic current flowing through resistors R
and R
transconductance amplifier (gm
of gm
R
equal to:
The I
compared to an internal 1.25V reference voltage. When the
voltage drop across R
configured for loop current detection, the DET pin goes low.
The hysteresis resistor R
effectively across R
threshold to be slightly higher than the off-hook to on-hook
threshold.
Taking into account the hysteresis voltage, the typical value
of R
Taking into account the hysteresis voltage, the typical value
of R
I
R
R
RD
D
D
D
pin and through resistor R
=
=
D
D
=
RD
1
2
for the on-hook to off-hook condition is:
------------------------------------------------------------------------- -
I
for the off-hook to on-hook condition is:
------------------------------------------------------------------------- -
I
----------------------------------- -
ON HOOK to OFF
OFF HOOK to ON
. This results in a current (I
I
and the metallic loop current. I
TIP
current results in a voltage drop across R
1
–
600
–
–
is the metallic loop current plus the longitudinal
I
RING
465
375
1
and R
D
=
, causing the on-hook to off-hook
D
--------- -
300
I
L
exceeds 1.25V, and the logic is
–
–
H
2
HOOK
HOOK
. Notice that for case 2,
adds an additional voltage
D
1
to V
) that is equal to the product
RD
EE
) out of the
RD
. The value of I
2
is the metallic loop
then flows out the
D
that is
(EQ. 24)
(EQ. 25)
(EQ. 26)
RD
is
1