Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Interface > Telecom

Skyworks Solutions Inc. SI32174-C-FM1R

Name: SI32174-C-FM1R
Brand: Skyworks Solutions Inc.
SKU: SI32174-C-FM1R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: SI32174-C-FM1R

Manufacturer:: Skyworks Solutions Inc.

Category:: Telecom

Package:: 42-VFQFN Exposed Pad

Datasheet:: SI32174-C-FM1R.pdf

Description:: IC TELECOM INTERFACE 42QFN

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,490

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

SI32174-C-FM1R from Skyworks Solutions is a single-channel ProSLIC® FXS interface IC implementing full BORSCHT functionality for VoIP telephony endpoints. It operates from 3.3 V, supports PCM/SPI digital interfaces (1.8 V or 3.3 V I/O), integrates a tracking dc-dc controller for –110 V battery generation, delivers DTMF detection and wideband voice support, and targets analog terminal adapters and VoIP DSL gateways.

For engineers reviewing the SI32174-C-FM1R datasheet, SI32174-C-FM1R pinout, SI32174-C-FM1R application, or SI32174-C-FM1R equivalent, key selection considerations include its –110 V battery rating, integrated ringing generator with programmable cadence/frequency, on-chip transhybrid balance filter, loop closure/ground key detection thresholds, and support for A-law/μ-law companding in 8-bit or linear PCM mode.

Technical Context

The SI32174-C-FM1R implements a complete FXS line interface with integrated codec, ADC/DAC, programmable AC impedance synthesis, and a flyback dc-dc controller that directly drives external MOSFETs to generate –110 V battery voltage. Its digital interface supports both SPI control (up to 16 MHz) and PCM/GCI highway (PCLK up to 8.192 MHz) with programmable interrupts and GCI/IOM-2 mode.

It performs all BORSCHT functions-including battery feed (10–45 mA DC current), overvoltage protection, ringing (108 V_PK, 16–60 Hz), supervision (loop closure, ring trip, ground key), coding (A-law/μ-law, linear PCM), hybrid (transhybrid balance ≥26 dB), and testing-while enabling software-programmable parameters such as two-wire impedance, ringing waveshape, and DC feed current limits.

Key Specifications

Parameter	Value and Actual Design Meaning
Battery Voltage Rating	–110 V maximum; enables compliance with LSSGR/ITU-T ringing requirements for short-to-medium loops.
DC Feed Current Range	10–45 mA; software-configurable to match line resistance and regulatory loop current specifications.
Ringing Amplitude	108 V_PK (open-circuit); supports global ringing standards including North American 20 Hz/90 V_RMS equivalents.
DTMF Detection	Integrated hardware DTMF detector (per datasheet Table 6.9); eliminates need for external tone decoder in ATA/CPE designs.
Wideband Voice Support	Validated for Si32174/6/7 variants; enables 7 kHz audio bandwidth for HD voice applications beyond narrowband PSTN.
Supply Voltage	3.3 V ±3.3% (VDD), 1.71–3.47 V (VDDIO); allows direct interfacing with 1.8 V or 3.3 V host processors without level shifters.
Package	5 × 7 mm 42-pin QFN; exposes thermal pad (HVPAD) for high-power dissipation during ringing and off-hook operation.

Pinout & Package

The SI32174-C-FM1R is housed in a 5 × 7 mm, 42-pin QFN package with exposed thermal pad (HVPAD) soldered to PCB copper for thermal management. Pin 42 and Pin 1 are HVPAD; Pin 44 is GNDPAD. The package complies with Pb-free/RoHS requirements.

Pin/Terminal	Circuit Role	Design Meaning
TIP / RING	Two-wire line interface terminals	Direct connection to telephone line; support balanced ringing, on-hook transmission, and metallic loop testing.
STIPDC / SRINGDC	DC linefeed sense inputs	Monitor tip/ring DC voltage for supervision states (on-hook, off-hook, ring trip) with ±4 V accuracy.
STIPAC / SRINGAC	AC linefeed sense inputs	Enable AC-coupled ring trip detection and longitudinal noise measurement per ITU-T K.21.
GPIO1/STIPC / GPIO2/SRINGC	Configurable general-purpose I/O	Can be assigned as polarity reversal control or custom status outputs; supports smooth polarity reversal timing.
DCDRV / DCFF / SDCH / SDCL	Flyback dc-dc controller outputs	Drive external MOSFETs and gate drive transformer to generate –110 V battery; require no external PWM controller.
VDD / VDDIO / VDDREG	Power supply rails	VDD (3.3 V core), VDDIO (1.8/3.3 V I/O), VDDREG (internal 1.2 V regulator output for analog blocks).
SCLK / SDI / SDO / CS / FSYNC / PCLK / DTX / DRX	Digital interface signals	Full SPI (4-wire) and PCM/GCI (8-bit time-slot) support; enable simultaneous control and real-time voice transport.

Key Features

Feature	Design Value
Patented low-power ringing	Reduces average ringing power consumption by >30% vs. conventional flyback topologies, extending system thermal margin.
Software-programmable ringing	Full control of frequency (16–60 Hz), amplitude (108 V_PK), cadence (±50 ms accuracy), and waveshape via SPI register writes.
Integrated transhybrid balance filter	26–30 dB return loss across 300 Hz–3.4 kHz; minimizes echo without external components or calibration.
On-chip DTMF detection	Dedicated hardware detector compliant with ETSI ES 201 235-1; reduces host CPU load and eliminates external tone decoder IC.
Automatic power save mode	Reduces IDD from 31.2 mA to 10.8 mA in on-hook state; critical for energy-efficient CPE and battery-backed gateways.

Applications

VoIP Analog Terminal Adapters (ATA)	Small Office/Home Office (SOHO) PBX
Use Scenario: Converting analog phones to SIP/VoIP networks in residential or remote office settings. IC Role / Device Role / Timing Role: Full FXS line interface performing BORSCHT functions, including battery feed, ringing, supervision, and PCM voice encoding/decoding. Use Value: Enables single-chip integration of telephony interface with <110 V battery capability, eliminating discrete dc-dc converters and reducing BOM count by 4+ components.	Use Scenario: Multi-line business phone systems supporting analog extensions and PSTN backup lines. IC Role / Device Role / Timing Role: FXS channel providing loop start signaling, polarity reversal, and DTMF detection for extension port control. Use Value: Software-configurable DC feed (10–45 mA) and ring trip thresholds ensure compatibility with diverse analog phone models and legacy wiring.
VoIP DSL Gateways and Routers	Wireless Local Loop (WLL) Base Stations
Use Scenario: Integrated broadband gateways combining DSL modem, router, and 1–4 FXS ports for triple-play service delivery. IC Role / Device Role / Timing Role: Primary FXS interface handling PCM voice transport, caller ID injection, and line diagnostics over shared digital bus. Use Value: Wideband voice support (Si32174) enables HD voice codecs (e.g., G.722), improving call quality without additional DSP resources.	Use Scenario: Fixed wireless access nodes delivering POTS service over microwave or LTE backhaul in rural infrastructure. IC Role / Device Role / Timing Role: FXS line driver supporting long-loop (>2 km) operation with programmable impedance synthesis and longitudinal noise rejection. Use Value: Maximum loop resistance of 2000 Ω at 18 mA ensures reliable off-hook detection and battery feed over high-impedance subscriber loops.

VoIP Analog Terminal Adapters (ATA)

Small Office/Home Office (SOHO) PBX

Use Scenario: Converting analog phones to SIP/VoIP networks in residential or remote office settings.

IC Role / Device Role / Timing Role: Full FXS line interface performing BORSCHT functions, including battery feed, ringing, supervision, and PCM voice encoding/decoding.

Use Value: Enables single-chip integration of telephony interface with <110 V battery capability, eliminating discrete dc-dc converters and reducing BOM count by 4+ components.

Use Scenario: Multi-line business phone systems supporting analog extensions and PSTN backup lines.

IC Role / Device Role / Timing Role: FXS channel providing loop start signaling, polarity reversal, and DTMF detection for extension port control.

Use Value: Software-configurable DC feed (10–45 mA) and ring trip thresholds ensure compatibility with diverse analog phone models and legacy wiring.

VoIP DSL Gateways and Routers

Wireless Local Loop (WLL) Base Stations

Use Scenario: Integrated broadband gateways combining DSL modem, router, and 1–4 FXS ports for triple-play service delivery.

IC Role / Device Role / Timing Role: Primary FXS interface handling PCM voice transport, caller ID injection, and line diagnostics over shared digital bus.

Use Value: Wideband voice support (Si32174) enables HD voice codecs (e.g., G.722), improving call quality without additional DSP resources.

Use Scenario: Fixed wireless access nodes delivering POTS service over microwave or LTE backhaul in rural infrastructure.

IC Role / Device Role / Timing Role: FXS line driver supporting long-loop (>2 km) operation with programmable impedance synthesis and longitudinal noise rejection.

Use Value: Maximum loop resistance of 2000 Ω at 18 mA ensures reliable off-hook detection and battery feed over high-impedance subscriber loops.

Equivalent & Alternatives

The following parts are listed as comparable options for similar FXS interface applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SI32176-C-FM1R	Same pinout and firmware-compatible; rated for –110 V battery but includes enhanced wideband audio path and improved THD performance.	Preferred for HD voice deployments requiring >7 kHz bandwidth and lower distortion in transmit/receive paths.	Select SI32176-C-FM1R when wideband audio fidelity and reduced harmonic distortion are design priorities over cost.
SI32170-C-FM1R	Pin-compatible variant rated for –140 V battery; higher ringing amplitude (132 V_PK) and extended loop resistance support.	Suitable for long-loop WLL or industrial environments requiring higher fault tolerance and longer reach.	Choose SI32170-C-FM1R only if –140 V battery and 132 V_PK ringing are mandatory for regional telecom compliance.

Compared with SI32176-C-FM1R, the SI32174-C-FM1R offers identical FXS functionality and pinout but trades wideband THD improvement for lower system cost; versus SI32170-C-FM1R, it provides optimized thermal performance and reduced power draw for mid-range loop lengths where –110 V suffices.

Availability

SI32174-C-FM1R is available at Aetrix Electronics and suitable for VoIP analog terminal adapters, SOHO PBX systems, and DSL gateway designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for SI32174-C-FM1R includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Skyworks Solutions is a global semiconductor company specializing in analog and mixed-signal connectivity solutions for communications infrastructure, automotive, and industrial markets.

The SI3217x-C family is designed specifically for cost-sensitive, space-constrained FXS applications in customer premise equipment, delivering full BORSCHT functionality with integrated dc-dc control and software programmability.

FAQ

What is the maximum battery voltage supported by the SI32174-C-FM1R?

The SI32174-C-FM1R supports a maximum battery voltage of –110 V, as specified in Table 1 of the datasheet. This rating enables compliance with North American and ETSI ringing standards while maintaining thermal safety margins during sustained ringing operation. The SI32174-C-FM1R uses an internal tracking dc-dc controller to generate this voltage from a 3.3 V input.

Does the SI32174-C-FM1R support DTMF detection?

Yes, the SI32174-C-FM1R includes integrated hardware DTMF detection, explicitly confirmed in the "Si3217x-C Features" list and Table 6.9 of the datasheet. This feature eliminates the need for external tone decoders in ATA and gateway designs, reducing system complexity and host processor load while ensuring ETSI ES 201 235-1 compliance.

What digital interfaces does the SI32174-C-FM1R support?

The SI32174-C-FM1R supports dual digital interfaces: a 4-wire SPI bus for configuration and diagnostics (with SCLK up to 16 MHz), and a PCM/GCI highway interface (PCLK up to 8.192 MHz, FSYNC at 8 kHz) for real-time voice transport. Both interfaces operate with 1.8 V or 3.3 V I/O levels, and the device supports GCI/IOM-2 mode for flexible time-slot mapping.

Is the SI32174-C-FM1R pin-compatible with other Si3217x-C devices?

Yes, the SI32174-C-FM1R is pin-compatible with the entire Si3217x-C family, including SI32170/1/6/7/8/9 variants, as stated in the product description. This allows drop-in replacement across voltage ratings (–110 V vs. –140 V) and feature sets (e.g., DTMF detection, wideband audio) without PCB layout changes, provided firmware and external component values are adjusted accordingly.

What is the operating temperature range for the SI32174-C-FM1R?

The SI32174-C-FM1R is qualified for industrial-grade operation from –40 °C to +85 °C ambient temperature (G-grade), with a maximum junction temperature of 145 °C for the linefeed die. Thermal shutdown circuitry activates at 145 °C during normal operation and up to 200 °C during ringing cadence, ensuring reliability in enclosed CPE enclosures.

SI32174-C-FM1R Specifications

Product attributes: Attribute value

Manufacturer:: Skyworks Solutions Inc.

Series:: ProSLIC®

Package/Case:: 42-VFQFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Subscriber Line Interface Concept (SLIC), CODEC

Interface:: PCM, SPI

Number of Circuits:: 1

Voltage - Supply:: 3.13V ~ 3.47V

Current - Supply:: -

Power (Watts):: 750 mW

Operating Temperature:: 0°C ~ 70°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 42-QFN (5x7)

SI32174-C-FM1R FAQ

1.How can I place an order for SI32174-C-FM1R through Aetrix?

Please submit a Request for Quotation (RFQ) for SI32174-C-FM1R on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for SI32174-C-FM1R reliable?

The price and inventory of SI32174-C-FM1R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI32174-C-FM1R is usually 5 days.

3.What payment methods are accepted for SI32174-C-FM1R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI32174-C-FM1R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI32174-C-FM1R?

SI32174-C-FM1R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI32174-C-FM1R order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for SI32174-C-FM1R?

For technical support, including SI32174-C-FM1R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI32174-C-FM1R requirements.

6.How does Aetrix verify that SI32174-C-FM1R is sourced from the original manufacturer or authorized distributors?

All SI32174-C-FM1R products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SI32174-C-FM1R meets industry standards.

7.What is the process for return or replacement of SI32174-C-FM1R?

All SI32174-C-FM1R units undergo pre-shipment inspection (PSI). If there is an issue with SI32174-C-FM1R, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The SI32174-C-FM1R part is unused and in its original packaging.

Return procedure for SI32174-C-FM1R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…