FSA4480UCX - USB Type-C Audio Switch 25-WLCSP | onsemi
MPN: FSA4480UCX ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.7014 | $0.70 |
| 10 | $0.67 | $6.70 |
| 100 | $0.62 | $62.00 |
| 500 | $0.58 | $290.00 |
| 1,000 | $0.54 | $540.00 |
FSA4480UCX Overview
A USB Type-C analog audio switch is a special-purpose analog multiplexer that lets a single reversible USB Type-C connector carry multiple signal types simultaneously. In the port-sharing hierarchy, it sits between the USB Type-C receptacle and the application processor's USB PHY and audio codec, routing USB 2.0 data, analog left/right audio, sideband-use (SBU) lines, and analog microphone signals onto the shared pins. This eliminates dedicated 3.5 mm jacks and enables slimmer smartphone and tablet designs.
Key features of the FSA4480 include sharing of a common USB Type-C port to pass USB 2.0 signal, analog audio, sideband use wires, and analog microphone signal, plus support for high voltage on the SBU port and USB port on the receptacle side - critical because SBU pins can be exposed to fault voltages during accessory attach and cable orientation changes.
Technically, the device is fabricated as an integrated CMOS analog switch array with low on-state characteristics suited to audio-band signal integrity. The WLCSP (wafer-level chip-scale package) die size of 2.24 x 2.28 mm minimizes board area and shortens analog signal traces, which reduces insertion loss and crosstalk for audio and high-speed USB routing. The FSA4480 is documented in the onsemi datasheet 'USB Type-C Analog Audio Switch with Protection Function' (published 2019-11-22, 29 pages).
Typical applications include smartphones and tablets using a single Type-C connector for audio accessories, laptop and notebook audio-headset sharing, docking stations, and true-wireless charging cases requiring port consolidation. The protection function makes it especially suitable for consumer ports exposed to harsh accessory environments.
Design consideration: verify SBU high-voltage tolerance against your application's worst-case fault scenario, and keep WLCSP routing impedance-controlled; WLCSP packages require careful PCB fanout and do not support rework as easily as QFN alternatives.
This page synthesizes distributor pricing, cross-reference guidance, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for FSA4480UCX — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
FSA4480UCX-Z010
✅ Drop-In📋 Reference alternative (not in catalog)
FSA4480AUCX
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
FSA4480UCX Maximum Ratings & Electrical Characteristics
| Product Type | USB Type-C Analog Audio Switch |
| Function | USB Type-C port multimedia switch (audio headset support) |
| Channels | 6 |
| Signal Types | USB 2.0, analog audio, sideband use (SBU), analog microphone |
| Protection | High-voltage protection on SBU port and USB port (receptacle side) |
| Package | 25-WLCSP (2.24 x 2.28 mm) |
| Mounting Type | Surface Mount (WLCSP) |
| Brand | onsemi (ON Semiconductor) |
| Switching Time | 60 us / 15 us (per LCSC feature listing) |
| RoHS Status | Compliant (per distributor listing) |
| Application | Smartphone / tablet Type-C audio headset sharing |
| Datasheet Publication | 2019-11-22, 29 pages |
FSA4480UCX 25-wlcsp (2.24 x 2.28 mm) Pin Configuration Guide
Pin configuration for FSA4480UCX (25-wlcsp (2.24 x 2.28 mm) package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for FSA4480UCX.
Refer to the datasheet for full pin configuration.
Typical Applications
FSA4480UCX is suitable for 6 applications: Smartphone Type-C Audio Headset Sharing, Tablet and Notebook Port Consolidation, USB Type-C Docking Stations, True Wireless Earbud Charging Cases, Automotive Infotainment USB-C Audio Ports, Test and Measurement Audio Adapters.
Smartphone Type-C Audio Headset Sharing
The FSA4480UCX is purpose-built for smartphones that have removed the 3.5 mm jack and route analog audio through the USB Type-C connector. Its 6-channel switch array passes USB 2.0 data, analog left/right audio, and analog microphone signals over the shared Type-C pins, switching configuration automatically as accessories attach. The 2.24 x 2.28 mm WLCSP fits the dense mainboard routing near the connector, keeping analog traces short to minimize insertion loss and crosstalk. The integrated high-voltage protection on SBU and receptacle-side USB pins protects the audio codec and USB PHY when chargers, debug cables, or mis-wired accessories present fault voltages. Switching times of 60 us and 15 us ensure fast, click-free mode transitions during accessory plug-in events.
Recommended
Tablet and Notebook Port Consolidation
Tablets and thin notebooks use the FSA4480UCX to share a single reversible USB Type-C port between USB 2.0 data and analog headset audio, eliminating dedicated audio jacks and saving board space and connector BOM cost. The onsemi device passes analog audio and microphone signals with audio-band fidelity while maintaining USB 2.0 signal integrity when data accessories are connected. Its protection function withstands high voltage events on the SBU and USB receptacle-side pins - a common failure source in laptop docks and hub environments. Designers should place the switch within a few millimeters of the Type-C receptacle to keep stub lengths minimal, and control impedance on USB 2.0 pairs. The 25-ball WLCSP requires precise land-pattern adherence to the onsemi datasheet footprint.
Recommended
USB Type-C Docking Stations
Docking stations benefit from the FSA4480UCX's ability to arbitrate between USB 2.0 data and analog audio on a shared port. When a host laptop connects, the dock's controller selects the FSA4480 switch configuration to route headset analog audio to the codec or USB 2.0 data to the hub controller. The high-voltage tolerance on SBU and receptacle-side USB pins protects the dock from fault conditions arising from mixed accessory populations - chargers, legacy adapters, and non-compliant cables. The switch's 60 us transition time supports hot-swap audio sessions without long mute intervals. Because docks run continuously, the CMOS switch architecture's low quiescent consumption and analog-switch linearity preserve audio quality across extended operating sessions in office and home dock environments.
Recommended
True Wireless Earbud Charging Cases
True-wireless earbud charging cases increasingly adopt USB Type-C connectors, and the FSA4480UCX lets a single small port serve charging-communication, firmware-update USB 2.0 data, and in some architectures accessory audio or debug signaling. The 2.24 x 2.28 mm WLCSP suits the extremely space-constrained case PCB, where every square millimeter matters around the charging IC and wireless coexistence circuits. The SBU high-voltage protection guards the switch when users connect arbitrary cables and chargers that may present unexpected potentials on sideband pins. Distributor-listed switching times of 60 us and 15 us allow rapid mode switching between charge communication and data modes. Its low on-state characteristics preserve signal integrity for the case-to-bud communication path routed through the shared connector.
Recommended
Automotive Infotainment USB-C Audio Ports
Automotive head units and rear-seat entertainment systems moving to USB Type-C can use the FSA4480 (automotive variant availability must be confirmed with onsemi) to share the connector between USB 2.0 device data and analog microphone/audio lines for hands-free accessories. The integrated high-voltage protection is especially valuable in vehicles, where accessory ports face harsh electrical environments including load-dump-adjacent transients and non-compliant aftermarket cables plugged in by passengers. The 25-WLCSP package withstands standard consumer reflow assembly; confirm the automotive temperature grade from the appropriate onsemi ordering variant before qualification. The 60 us mode-switch time keeps audio session transitions imperceptible during source changes. Protection on the receptacle-side USB pins adds a defensive layer against service-shop test equipment misconnection events.
Recommended
Test and Measurement Audio Adapters
Bench audio adapters and Type-C audio dongles use the FSA4480UCX to route analog audio from measurement sources or DUTs through a Type-C connector, replicating the port-sharing behavior of consumer devices under test. Test engineers value the device's protection function, which survives accidental connection of powered accessories during probing. The low on-state switch characteristics preserve audio-band measurement accuracy, and the small WLCSP allows adapter dongle PCBs smaller than the connector shell itself. Switching times of 60 us and 15 us support automated test sequences that alternate between USB 2.0 data verification and analog audio analysis on the same port. When building such fixtures, reference the onsemi 29-page datasheet ball-map exactly and verify pin 1 ball orientation to avoid mirrored layouts common with WLCSP probing.
Recommended
Recommended Products Summary
Engineering reference data for FSA4480UCX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | FSA4480UCX-Z010 | FSA4480AUCX |
|---|---|---|---|
| Package | 25-WLCSP (2.24 x 2.28 mm) | 25-WLCSP (2.24 x 2.28 mm) - same | 25-WLCSP (2.24 x 2.28 mm) - same |
| Brand | onsemi | onsemi | onsemi |
| Channels | 6 | 6 | 6 |
| Signal Types Supported | USB 2.0, analog audio, SBU, analog mic | Identical (same die) | Identical family function |
| SBU/USB High-Voltage Protection | Yes | Yes | Yes |
| Grade / Qualification | Consumer/industrial | Consumer/industrial (same) | Automotive-grade family variant (verify grade) |
Key Differentiators
- Purpose-built Type-C port sharing (vs Generic analog mux)
- Integrated SBU high-voltage protection (vs FSA4480 family without protection function (older muxes))
- Packaging-option second source within family (vs FSA4480UCX-Z010)
Design Notes
The FSA4480UCX uses a 25-ball WLCSP (2.24 x 2.28 mm) with a fine ball pitch, so the PCB land pattern must be taken directly from the onsemi datasheet package section - do not approximate from generic WLCSP-25 footprints. Place the switch within a few millimeters of the Type-C receptacle to keep SBU and USB 2.0 stubs short. Route USB 2.0 pairs as 90-ohm differential with matched lengths, and route analog audio away from the USB pairs to limit crosstalk. Use non-solder-mask-defined (NSMD) pads for best assembly yield on WLCSP balls.
Do not assume SBU high-voltage tolerance covers all fault scenarios: the protection function guards the receptacle-side SBU and USB pins per the datasheet, but downstream codec inputs should still have their own ESD/clamping strategy per system-level requirements. Also beware of cable orientation: the switch must be controlled by a Type-C controller that reports cable flip status so the FSA4480 selects the correct SBU pair for analog audio. Verify switching time budget (60 us / 15 us per distributor listings) against your pop-click suppression scheme during audio session transitions.
Because WLCSP parts are difficult to rework, validate the assembly process with a test coupon before production. Keep the switch control lines (driven by your Type-C PD/controller) short and away from the analog audio path to prevent digital coupling into the audio band. Star-route the ground connection so analog audio return currents and USB return currents do not share a narrow trace. Estimated: keeping total trace length from receptacle to switch under 10 mm keeps parasitic capacitance low enough to preserve USB 2.0 eye margins in typical 4-layer stackups.
Compliance Information
RoHS compliance noted in DigiKey/LCSC distributor listings. REACH, lead-free, halogen-free and conflict-minerals statuses must be confirmed from onsemi compliance documents.
