SI32178-B-GMR

Telecom Overview

The SI32178-B-GMR is a single-channel ProSLIC integrated circuit designed as a complete foreign exchange station (FXS) telephony interface solution. It complies with LSSGR, ITU, and ETSI specifications and supports PCM/SPI digital interfaces. The device operates from a 3.3 V supply voltage ranging between 3.13 V and 3.47 V. It features an integrated DC-DC controller that generates optimal battery voltages up to -110 V for line states. Key capabilities include DTMF detection, wideband voice support, and optional FXO isolation via capacitive technology. The component is housed in a 5x7 mm 42-pin QFN package.

Telecom Feature Summary

• Performs all BORSCHT functions including programmable AC impedance and hybrid circuits
• Integrates a tracking DC-DC controller for automatic battery voltage generation
• Supports global programmability and simplified configuration through the ProSLIC API
• Enables seamless connection to Si3291x series FXO devices using patented capacitive isolation

Telecom Applications

• Customer Premise Equipment (CPE)
• VoIP DSL Gateways and Routers
• Wireless Local Loop (WLL)
• Integrated Access Devices (IAD)
• Analog Terminal Adapters (ATA)

Telecom Procurement Notes

Verify the specific suffix against official Skyworks documentation to confirm temperature grade and feature set. Confirm availability status as distribution channels may list obsolete or end-of-life inventory. Ensure the procurement source provides valid datasheets matching the exact part number to avoid functional mismatches.

Telecom Selection Notes

Select this model when DTMF detection and wideband voice processing are required alongside standard FXS functionality. Verify compatibility with the host DSP or microcontroller's SPI or PCM interface timing. Consider the -110 V battery voltage rating for loop resistance requirements. Ensure the design accommodates the 42-pin QFN thermal dissipation characteristics.

Telecom Part Context

This component belongs to the Si3217x family of ProSLIC products manufactured by Silicon Laboratories. It is pin-compatible with other members of the series, such as the Si32176 and Si32177, which offer variations in battery voltage ratings and feature sets like pulse metering. The family shares a common architecture for single-channel telephony interfaces.

Telecom Replacement Considerations

Direct substitutes within the same family include the Si32178-B-FM, which offers identical electrical performance but operates within a commercial temperature range of 0 to 70 °C instead of the industrial range.