SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 30

• Manufacturer Part Number: SI3220-KQ
• Description: IC SLIC/CODEC DUAL-CH 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3220-KQ

• Package / Case: *
• Function: Subscriber Line Interface Concept (SLIC), CODEC
• Interface: GCI, PCM, SPI
• Number Of Circuits: 2
• Voltage - Supply: 3.3V, 5V
• Current - Supply: 65mA
• Power (watts): 941mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Includes: Battery Switching, BORSCHT Functions, DTMF Generation and Decoding, FSK Tone Generation, Modem and Fax Tone Detection
• Product: Telecom
• Supply Voltage (min): 3.13 V
• Supply Current: 22 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

Si3220/Si3225
The dc linefeed circuitry generates the necessary TIP/
RING I/V characteristics along with loop closure and
ring trip detection. For loop start applications, V
V
software programmable with a range from 18–45 mA.
Figure 16 illustrates the linefeed characteristics for a
typical application using an I
a TIP-RING open circuit voltage (V
VOC and VOCTRACK RAM locations are used to
program the TIP-RING voltage, and these two values
are equal when V
battery voltage drops below that point, VOCTRACK
decreases at the same rate as V
provide sufficient headroom to accommodate both V
and V
The equation for calculating the RAM address value for
VOC, VCM, VOCDELTA, VOV, VOVRING, RINGOF,
VOCLTH, and VOCHTH is shown below. The CEILING
function rounds up the result to the next integer.
For example, to program a VOC value of 51 V:
30
VOC
Linefeed
Linefeed Shadow
Battery Feed Control
Loop Current Limit
On-Hook Line Voltage
Common Mode Voltage
V
V
Low
V
High
Overhead Voltage
Ringing Overhead Volt-
age
V
Tracking
RING
OC
OC
OC
OC
RAM VALUE
2
Delta for Off-Hook
Delta Threshold,
Delta Threshold,
During Battery
CM
=
is programmable. The loop current limit (I
×
Parameter
CEILING
2
levels below VBAT.
×
CEILING


ROUND
=
BAT


ROUND
Table 18. Register and RAM Locations for Linefeed Control
> V


OC
desired voltage
--------------------------------------- -
Register/RAM
LOOP
VOCTRACK
RELAYCON
VOCDELTA


Mnemonic
LINEFEED
LINEFEED
+ V
1.005V
VOVRING
VOCHTH
------------------ -
1.005V
VOCLTH
51V
VOC
VCM
VOV
ILIM
OV
setting of 24 mA and
BAT
+ V


OC
×
) of 48 V. The


512
--------- -
CM
5
decreases to
×
512
--------- -


. When the
5
=
VOCTRACK[15:0]
VOCDELTA[14:0]
Preliminary Rev. 0.91


VOVRING[14:0]
VOCHTH[15:0]
Register/RAM
VOCLTH[15:0]
28CEh
LIM
VCM[14:0]
VOC[14:0]
VOV[14:0]
ILIM[4:0]
LFS[2:0]
BATSEL
LF[2:0]
TIP
) is
OV
Bits
-
During the on-hook state, the Si3220/Si3225 is in the
constant voltage operating area and typically presents a
640 Ω output impedance (Figure 16). The Si3220 and
Si3225 include a special modified linefeed scheme
called Modfeed
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 Si3220/Si3225 to reduce its output
impedance to 320 Ω . The TIP-RING voltage will then
continue decreasing until the preset loop current limit
(I
detection thresholds are programmable and include
internal debouncing. A high-gain common mode loop
generates a low-impedance from TIP or RING to
ground, effectively reducing the effects of longitudinal
interference.
LIM
) setting is reached. Loop closure and ring trip
Programmable
VBATH/VBATL
See Table 17
Monitor Only
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
0 to 63.3 V
18–45 mA
Range
™
, which adjusts the ProSLIC’s output
LSB Size
0.875 mA
4.907 mV
4.907 mV
4.907 mV
4.907 mV
4.907 mV
4.907 mV
4.907 mV
4.907 mV
N/A
N/A
N/A
Resolution
0.875 mA
Effective
1.005 V
1.005 V
1.005 V
1.005 V
1.005 V
1.005 V
1.005 V
1.005 V
N/A
N/A
N/A