SI3232-KQ Silicon Laboratories Inc, SI3232-KQ Datasheet - Page 24

• Manufacturer Part Number: SI3232-KQ
• Description: IC SLIC PROG DUAL-CH 64TQFP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI3232-KQ

• Package / Case: *
• Function: Subscriber Line Interface Concept (SLIC)
• Interface: ISDN
• Number Of Circuits: 2
• Voltage - Supply: 3.13 V ~ 3.47 V
• Current - Supply: 28mA
• Power (watts): 280mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Product: SLIC
• Supply Voltage (min): 3.13 V
• Supply Current: 28 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Number Of Channels: 2
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Si3232
levels below V
The equation for calculating the RAM address value for
VOC, VCM, VOCDELTA, VOV, VOVRING, RINGOF,
VOCLTH, and V
function rounds up the result to the next integer.
For example, to program a VOC value of 51 V:
During the on-hook state, the Si3232 is in the constant-
voltage operating area and typically presents a 640 Ω
output impedance (Figure 8). The Si3232 includes a
special modified linefeed scheme called “Modfeed™”,
which adjusts the ProSLIC’s output impedance based
on the linefeed voltage level in order to ensure the
ability to source extended loop lengths. When the
terminal equipment transitions to the off-hook state, the
linefeed voltage typically collapses and transitions
through the preset Modfeed threshold voltage causing
the Si3232 to reduce its output impedance to 320 Ω.
The TIP-RING voltage will then continue decreasing
until the preset loop current limit (I
reached. Loop closure and ring trip detection thresholds
are programmable, and internal debouncing is provided.
A high-gain common-mode loop generates a low
impedance from TIP or RING to ground, effectively
reducing the effects of longitudinal interference.
For ground-start operation, the active lead presents a
640 Ω output impedance during the on-hook state and a
320 Ω output impedance in the off-hook state. The
“open” lead presents a high-impedance feed (>150 kΩ).
Figure 9 illustrates a typical ground-start application
using V
state.
debouncing interval are both programmable.
24
VOC
RAM VALUE
2
=
×
OC
The
2 CEILING ROUND
CEILING ROUND
×
= 48 V and I
BAT
ring
OCHTH


.
=


ground-detection
is shown below. The CEILING
LIM


desired voltage
--------------------------------------- -
= 24 mA in the TIP OPEN


------------------- -
1.005 V
1.005V
51 V


×
512
--------- -
threshold
LIM


5
×


) setting is
512
--------- -
5
=
Preliminary Rev. 0.95


28CEh
and
The Modfeed scheme also allows the user to modify the
apparent V
linefeed voltage when the battery voltage drops below a
certain level. Figure 10 illustrates a typical Si3232
application using Modfeed while sourcing a loop from a
48 V battery. For V
VOCTRACK RAM location will be set to 42 V when
given a programmed value of 42 V for the VOC RAM
location. When a loop closure event occurs, the TIP-
RING voltage decreases linearly until it reaches a
preset voltage threshold that is lower than VOCTRACK
by an amount programmed into the VOCLTH RAM
location. Exceeding this threshold causes the Dual
ProSLIC to increase its “target” V
programmed into the VOCDELTA RAM location to
provide additional overhead for driving the higher-
impedance loop. In the on-hook condition, the TIP-
RING voltage increases linearly until it rises above a
second preprogrammed voltage threshold, which is
higher than VOCTRACK by an amount programmed
into the VOCHTH RAM location. This scheme offers the
ability to drive very long loop lengths while using the
lowest possible battery voltage. Consult the factory for
optimal register and RAM location settings for specific
applications.
Figure 10. V
VOCDELTA
V
V
VOCTRACK
TIP
OC
–
50
40
30
20
10
0
RING
OC
R
TIP–RING
O
voltage as a means of boosting the
(V)
= 600 Ω
using Modfeed™
OV
10
and V
vs. I
load line
1930 Ω
LOOP
CM
OC
20
values of 3 V, the
Characteristics
level by an amount
R
O
= 320 Ω
I
LIM
(mA)