SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 38

• 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
Automatic Dual Battery Switching
The Dual ProSLIC chipsets provide the ability to switch
between several user-provided battery supplies to aid
thermal management. Two specific scenarios where
this method may be required are as follows:
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Ground Key Interrupt
Pending
Ground Key Interrupt
Enable
Ground Key Linefeed
Shadow
Ground Key Detect Status
Ground Key Detect
Debounce Interval
Longitudinal Current Sense
Ground Key Threshold
(enabled)
Ground Key Threshold
(released)
Ground Key Filter Coeffi-
cient
*Note: The usable range for LONGHITH and LONGLOTH is limited to 16 mA. Setting a value > 16 mA will disable
Ringing to off-hook state transition (Si3220):
During the on-hook operating state, the Dual
ProSLIC chipset must operate from the ringing
battery supply to provide the desired ringing signal
when required. Once an off-hook condition is
detected, the Dual ProSLIC chipset must transition
to the lower battery supply, typically –24 V, to reduce
power dissipation during the active state. The low
current consumed by the Dual ProSLIC chipset
during the on-hook state results in very little power
dissipation while being powered from the ringing
battery supply, which can have an amplitude as high
as –100 V depending on the desired ringing
amplitude.
On-hook to off-hook state, short loop feed
(Si3225): When sourcing both long and short loop
lengths, the Dual ProSLIC chipset can automatically
switch from the typical –48 V off-hook battery supply
to a lower off-hook battery supply (e.g., –24 V) to
threshold detection.
Parameter
Table 22. Register and RAM Locations Used for Ground Key Detection
Mnemonics
LONGLOTH
LONGHITH
LINEFEED
LONGLPF
LONGDBI
IRQVEC2
Register/
LCRRTP
IRQEN2
ILONG
RAM
Preliminary Rev. 0.91
LONGLPF[15:3]
LONGDBI[15:0]
Register/RAM
GLOTH[15:0]
ILONG[15:0]
HITH[15:0]
LFS[2:0]
LONGHI
LONGS
LONGE
LONG-
LON-
Bits
The BATSELa and BATSELb pins switch between the
two battery voltages based on the operating state and
the TIP-RING voltage. Figure 22 illustrates the chip
connections required to implement an automatic dual
battery switching scheme. When BATSEL is pulled
LOW, the desired channel is powered from the V
supply. When BATSEL is pulled HIGH, the V
source supplies power to the desired channel.
The BATSEL pins for both channels are controlled using
the BATSEL bit of the RLYCON register and can be
programmed to automatically switch to the lower battery
supply (V
low enough to allow proper operation from the lower
supply. When using the Si3220, this mode should
always be enabled to allow seamless switching
between the ringing and off-hook states. The same
switching scheme is used with the Si3225 to reduce
power by switching to a lower off-hook battery when
sourcing a short loop.
reduce the total off-hook power dissipation. The Dual
ProSLIC chipset continuously monitors the TIP-
RING voltage and selects the lowest battery voltage
required to power the loop when transitioning from
the on-hook to the off-hook state, thus assuring the
lowest power dissipation.
Programmable
BATL
Monitor only
Monitor only
Monitor only
0 to 40.96 s
101.09 mA*
101.09 mA*
0 to 4000h
Yes/No
Yes/No
Range
) when the off-hook TIP-RING voltage is
0 to
0 to
3.097 µ A
3.097 µ A
1.25 ms
LSB
Size
N/A
N/A
N/A
N/A
N/A
See Table 19
Resolution
396.4 µ A
396.4 µ A
1.25 ms
N/A
N/A
N/A
N/A
N/A
BATH
BATL