SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 51

• 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

Polarity Reversal
The Dual ProSLIC devices support polarity reversal for
message waiting functionality and various signaling
modes. The ramp rate can be programmed for a smooth
transition or an abrupt transition to accommodate
different application requirements. A wink function is
provided for special equipment that responds to a
smooth ramp to V
register bits required to program the polarity reversal
modes.
Setting the Linefeed register to the opposite polarity
immediately reverses (hard reversal) the line polarity.
For example, to transition from Forward Active mode to
Reverse Active mode changes LF[2:0] from 001 to 101.
Polarity reversal is accommodated in the OHT and
ground start modes. The POLREV bit is a read-only bit
that reflects if the device is in Polarity Reversal mode.
Parameter
Linefeed
Polarity Reversal Status
Wink Function
(Smooth transition to Voc=0V)
Smooth Polarity Reversal Enable
Smooth Polarity Reversal Ramp
Rate
Table 29. Register and RAM Locations used for Polarity Reversal
OC
= 0 V. Table 29 illustrates the
See table 15
Read only
1 = Ramp to 0 V
0 = Return to previous V
0 = Disabled
1 = Enabled
0 = 1 V/1.25 ms
1 = 2 V/1.25 ms
Programmable Range
Preliminary Rev. 0.91
For smooth polarity reversal, set the PREN bit to 1 and
the RAMP bit to 0 or 1 depending on the desired ramp
rate
accomplished by toggling the linefeed register from
forward to reverse modes as desired.
A wink function slowly ramps down the TIP-RING
voltage (V
VOC value (set in the VOC RAM location). This scheme
lights a message-waiting lamp in certain handsets. No
change to the linefeed register is necessary to enable
this function. Instead, the user sets the VOCZERO bit to
1 so that the TIP-RING voltage collapses to 0 V at the
rate programmed by the RAMP bit. Setting the
VOCZERO bit back to 0 returns the TIP-RING voltage
to its normal setting. With a software timer, the user can
automate the cadence of the wink function. Figure 32
illustrates the wink function.
(see
OC
OC
) to 1 followed by a return to the original
Table 29).
Register/RAM
VOCZERO
POLREV
LF[2:0]
RAMP
PREN
Bits
Si3220/Si3225
Polarity
Register/RAM
Mnemonic
LINEFEED
POLREV
POLREV
POLREV
POLREV
reversal
is
then
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