Si3220/Si3225
are intended to comply with relevant LSSGR and ITU
requirements for line-fault detection and reporting, and
Functional Description
The Dual ProSLIC chipset is a three-chip integrated measured values are stored in registers for later use or
solution that provides all SLIC, codec, and DTMF further calculations. The Si3220 and Si3225 also
detection/decoding functions needed for a complete include two per-channel relay drivers to support legacy
dual-channel analog telephone interface. Intended for systems implementing centralized test equipment.
®
multiple-channel long-loop (up to 18 kft) applications
requiring high-density line card designs, the Dual
ProSLIC chipset provides high integration and low-
power operation for applications, such as Central Office
(CO) and digital loop carrier (DLC) enclosures. The
Dual ProSLIC chipset is also ideal for short-loop
applications requiring a space-effective solution, such
as terminal adapters, integrated access devices (IADs),
PBX/key systems, and voice-over IP systems. The
chipset meets all relevant Bellcore LSSGR, ITU, and
ETSI standards.
A complete audio transmit and receive path is
integrated, including DTMF generation and decoding,
tone
generation,
ac
modem/fax
impedance
tone
detection,
and
programmable
synthesis,
programmable transhybrid balance and programmable
gain attenuation. These features are software-
programmable providing a single hardware design to
meet international requirements. Digital voice data
transfer occurs over a standard PCM bus, and control
data is transferred using a standard 4-wire serial
peripheral interface (SPI). The Si3220 and Si3225 can
The Si3220/Si3225 ICs perform all battery, overvoltage, also be configured to support a 4-wire general circuit
ringing, supervision, codec, hybrid, and test interface (GCI). The Si3220 and Si3225 are available in
(BORSCHT) functions on-chip in a low-power, small- a 64-lead TQFP, and the Si3200 is available in a
footprint solution. DTMF decoding and generation, thermally-enhanced 16-lead SOIC.
phase continuous FSK (caller ID) signaling, and pulse
Dual ProSLIC Architecture
metering are also integrated. All high-voltage functions
are implemented using the Si3200 Linefeed Interface IC The Dual ProSLIC chipset is comprised of a low-voltage
allowing a highly-programmable integrated solution that CMOS device that uses a low-cost integrated linefeed
offers the lowest total system cost.
interface IC to control the high voltages needed for
operating the terminal equipment connected to the
telephone line. Figure 15 on page 30 presents a
simplified diagram of the linefeed control loop circuit for
controlling the TIP and RING leads. The diagram
illustrates a single-ended model for simplicity, showing
either the TIP or the RING lead.
The internal linefeed circuitry provides programmable
on-hook voltage and off-current loop current, reverse
battery operation, loop or ground-start operation, and
on-hook transmission. Loop current and voltage are
continuously monitored using an integrated 8-bit
monitor A/D converter. The Si3220 provides on-chip
balanced 5 REN ringing with or without a programmable The Dual ProSLIC chipset produces line voltages and
dc offset eliminating the need for an external bulk ring currents on the TIP/RING pair using register-
generator and per-channel ringing relay. Both sinusoidal programmable settings in the Si3220 and Si3225 as
and trapezoidal ringing waveshapes are available. well as direct ac and dc voltage/current sensing from
Ringing parameters, such as frequency, waveshape, the line. The Si3200 LFIC provides a low-cost interface
cadence, and offset are available in registers to reduce for bridging the low-voltage CMOS devices to the high-
external controller requirements. The Si3225 supports voltage TIP/RING pair. Sense resistors allow the voltage
external ringing generation with ring relay driver and and current to be measured on each lead or across T-R
external ring trip sensing to address legacy systems using the low-voltage circuitry inside the Si3220 and
that implement a centralized ringing architecture. All Si3225 eliminating expensive analog sensing circuitry
ringing options are software-programmable over a wide inside the high-voltage Si3200. In addition, the total
range of parameters to address a wide variety of power inside the Si3200 is constantly monitored and
application requirements.
controlled to provide optimal reliability under all
operating conditions. The sensing circuitry is calibrated
for environmental and process variations to guarantee
accuracy with standard external resistor tolerances.
The Si3220/Si3225 ICs also provide a variety of line
monitoring and subscriber loop testing functions. All
versions have the ability to generate specific dc and
audio signals and continuously monitor and store all line
voltage and current parameters. This combination of
signal generation and measurement tools allows remote
line card and loop diagnostics without requiring
additional test equipment. These diagnostic functions
28
Rev. 1.0
SILICONIMAGE [ Silicon image ]
