SI3220-KQ Silicon Laboratories Inc, SI3220-KQ Datasheet - Page 47

• 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

required to produce adequate dc loop current in the off-
hook state. Depending on the loop length and the ring
trip method, the ac or dc ring trip detection circuits are
disabled by setting their respective ring trip thresholds
(RTACTH or RTDCTH) sufficiently high so it does not
trip under any condition.
Si3225 Ring Trip Detection
The Si3225 implements an external ring trip detection
scheme when using a standard battery-backed, external
ringing generator. In this application, the centralized
ringing generator produces an unbalanced ringing
signal that is distributed to individual TIP/RING pairs. A
per-channel ringing relay is required to disconnect the
Si3225 from the TIP/RING pair and apply the ringing
signal. By monitoring the ringing feed path across a ring
feed sense resistor (R
the ringing source, the Si3225 can detect the dc current
path created when the hook switch inside the terminal
equipment closes. The internal ring trip detection
circuitry is identical to that illustrated in Figure 27.
Figure 31 illustrates the typical external ring trip circuitry
required for the Si3225. Because of the long loop nature
of these applications, a dc ring trip detection scheme is
used typically. The user can disable the ac ring trip
detection circuitry by setting the RTACTH threshold
sufficiently high so it does not trip under any condition.
Relay Driver Considerations
The Dual ProSLIC devices include up to three
dedicated relay drivers to drive external ringing and/or
test relays. Test relay drivers TRD1a, TRD1b, TRD2a,
and TRD2b are provided in all product versions, and
ringing relay drivers RRDa and RRDb are included for
the Si3225 only. In most applications, the relay can be
driven directly from the Dual ProSLIC with no external
relay drive circuitry required. Figure 28 illustrates the
internal relay driver circuitry using a 3 V or 5 V relay.
RING
in Figure 31) in series with
Preliminary Rev. 0.91
The internal driver logic and drive circuitry is powered
by the same V
(VDD1–VDD4 pins). When operating external relays
from a V
internal diode network provides protection against
overvoltage conditions from flyback spikes when the
relay is opened. Both 3 V or 5 V relays can be used in
the configuration shown in Figure 28 and either
polarized or non-polarized relays are acceptable if the
V
impedance (R
11 Ω while sinking less than the maximum rated 85 mA
into the pin.
If the operating voltage of the relay (V
the Dual ProSLIC’s V
drive circuit is required to eliminate leakage from V
V
configuration, a polarized relay will provide optimal
overvoltage
components. Figure 29 illustrates the required external
drive circuit and Table 28 provides recommended
values for R
supplies. The output impedance (R
driver pins is a constant 63 Ω while sourcing less than
the maximum rated 28 mA out of the pin.
CC
DD
Figure 28. Dual ProSLIC Internal Relay Drive
Si3220/
Si3225
through the internal protection diode. In this
and V
Driver
Relay
Logic
CC
DRV
supply equal to the chip’s V
DD
IN
DD
protection
) of the relay driver pins is a constant
for typical relay characteristics and V
supply as the chip’s main V
supplies are identical. The input
GDD
V
DD
Circuitry
DD
Si3220/Si3225
supply voltage, an external
and
TRD1a/b
TRD2a/b
RRDa/b
minimal
OUT
CC
V
CC
) is higher than
) of the relay
DD
non-polarized)
3 V/5 V Relay
(polarized or
supply, an
DD
external
supply
CC
CC
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to