SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 35

• 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

Power Dissipation Considerations
The Dual ProSLIC chipset is designed with the ability to
source long loop lengths in excess of 18 kft, but can
also accommodate short loop configurations. For
example, the Si3220 can operate from one of two
battery supplies depending on the operating state.
When in the on-hook state, the on-hook loop feed is
generated from the ringing battery supply, generally –
70 V or more. Once the SLIC transitions to the off-hook
state, a lower off-hook battery supply (typically –24 V)
supplies the required current to power the loop if the
loop length is sufficiently short to accommodate the
lower battery supply. This battery switching method
allows the SLIC chipset to dissipate less power than is
possible if operating from a –70 V battery supply. See
"Automatic Dual Battery Switching" on page 38 for more
details.
In long loop applications, there is generally a single
battery supply (e.g., –48 V) available for powering the
loop in the off-hook state. When sourcing loop lengths
similar to the maximum specified service distance (e.g.,
18 kft.), most of the power is dissipated in the
impedance of the line. SLICs used in long-loop
applications must also be able to provide phone service
to customers who are located much closer to the line
card than the maximum loop length specified for the
system. This situation may cause substantial power to
be dissipated inside the SLIC chipset, often resulting in
thermal shutdown or destruction of the device due to
thermal runaway.
Si3200 Total Power Output Monitor
Si3200 Power Alarm Interrupt Pending
Si3200 Power Alarm Interrupt Enable
Q1/Q2 Power Alarm Threshold
Q3/Q4 Power Alarm Threshold
Q5/Q6 Power Alarm Threshold
Q1/Q2 Thermal LPF Pole
Q3/Q4 Thermal LPF Pole
Q5/Q6 Thermal LPF Pole
Q1–Q6 Power Alarm Interrupt Pending
Q1–Q6 Power Alarm Interrupt Enable
Table 20. Register and RAM Locations Used for Power Monitoring and Power Fault Detection
Parameter
Register/RAM
Mnemonic
IRQVEC3
IRQVEC3
Preliminary Rev. 0.91
IRQEN3
IRQEN3
PLPF12
PLPF34
PLPF56
PTH12
PTH34
PTH56
PSUM
The Dual ProSLIC devices rely on the Si3200 to power
the line from the battery supply. The PCB layout and
enclosure conditions should be designed to allow
sufficient thermal dissipation out of the Si3200, and a
programmable power alarm threshold ensures product
safety under all operating conditions. See "Power
Monitoring and Power Fault Detection" on page 33 for
more details on power alarm considerations.
The Si3200’s thermally enhanced SOIC-16 package
offers an exposed pad that improves thermal dissipation
out of the package when soldered to a topside PCB pad
connected to inner power planes. Using appropriate
layout practices, the Si3200 can provide a thermal
performance of 65 °C/W. The exposed path should be
connected to a low-impedance ground plane via a
topside PCB pad directly under the part. See package
outlines for PCB pad dimensions. In addition, an
opposite-side PCB pad with multiple vias connecting it
to the topside pad directly under the exposed pad will
further improve the overall thermal performance of the
system. Contact the factory for layout guidelines for
optimal thermal dissipation.
Loop Closure Detection
Loop closure detection is required to accurately signal a
terminal device going off-hook during the Active or On-
Hook Transmission linefeed states (forward or reverse
polarity). The functional blocks required to implement a
loop closure detector are shown in Figure 20, and the
register set for detecting a loop closure event is
Register/RAM
PLPF12[15:0]
PLPF34[15:0]
PLPF56[15:0]
PQ1S–PQ6S
PQ1E–PQ6E
PTH12[15:0]
PTH34[15:0]
PTH56[15:0]
PSUM[15:0]
PQ1S
PQ1E
Bits
Measurement
See “Power Filter and Alarms”
See “Power Filter and Alarms”
See “Power Filter and Alarms”
0 to 16.319 W
0 to 16.319 W
0 to 16.319 W
Si3220/Si3225
0 to 1.03 W
Range
N/A
N/A
N/A
N/A
Resolution
31.4 µ W
498 µ W
498 µ W
498 µ W
N/A
N/A
N/A
N/A
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