Si32172/3/5

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Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

Rev. 1.0 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • August 31, 2021

4. Functional Description

Figure 13. Si32172/3/5 Functional Block Diagram

The Si32172/3/5 series provides all SLIC, codec, DTMF detection, and signal generation functions needed for one

complete analog telephone interface. The Si32172/3/5 performs all battery, over-voltage, ringing, supervision,

codec, hybrid, and test (BORSCHT) functions; it also supports extensive metallic loop testing capabilities.

The Si32172/3/5 provides a standard voice-band (200 Hz–3.4 kHz) audio codec and, optionally, an audio codec

with both wideband (50 Hz–7 kHz) and standard voice-band modes. The wideband mode provides an expanded

audio band with a 16 kHz sample rate for enhanced audio quality while the standard voice-band mode provides

standard telephony audio bandwidth. The Si32172/3/5 incorporates a programmable dc-dc converter controller

that reacts to line conditions to provide the optimal battery voltage required for each line-state. Si32172/3/5 ICs are

available with voltage ratings of –110 V or –140 V to support a wide range of ringing voltages; see "9. Ordering

Guide‚" on page 37 for the voltage rating of each Si32172/3/5 version.

Programmable on-hook voltage, programmable off-hook loop current, reverse battery operation, loop or ground

start operation, and on-hook transmission are supported. Loop current and voltage are continuously monitored by

an integrated monitoring ADC.

The Si32172/3/5 supports balanced 5 REN ringing with or without a programmable dc offset. The available voltage

offset, frequency, waveshape, and cadence options are designed to ring the widest variety of terminal devices and

to reduce external controller requirements.

A complete audio transmit and receive path is integrated, including ac impedance and hybrid gain. These features

are software-programmable, allowing a single hardware design to meet global requirements.

RING

TIP

SPI

Interface

DSP

DTMF &

Tone Gen

Caller ID

Ringing

Generator

ADC

DAC

CODEC

SLIC

Linefeed

Control

Linefeed

Monitor

DC-DC Controller

Line Diagnostics

PLL

PSCLK

MISO

MOSI

Integrated

Serial

Interface

DSP

DTMF &

Tone Gen

Caller ID

Ringing

Generator

ADC

DAC

CODEC

CODEC

SLIC

Linefeed

Control

Linefeed

Monitor

DC-DC Controller

Line Diagnostics

PLL

Si32172/3/5

ADC

DAC

FXS