PI2USB4122ZHEX - USB 3.2 Gen 1 4:1 Mux/DeMux Switch | Diodes Inc
MPN: PI2USB4122ZHEX ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.85 | $3.85 |
| 10 | $3.42 | $34.20 |
| 100 | $2.96 | $296.00 |
| 500 | $2.55 | $1,275.00 |
| 1,000 | $2.15 | $2,150.00 |
PI2USB4122ZHEX Overview
A USB switch (also called a USB mux/demux or USB crossbar switch) is a high-speed analog multiplexer designed to route USB 2.0 and SuperSpeed USB signals between multiple physical connectors or controllers while preserving signal integrity. As a category, USB switches sit within the broader hierarchy of analog switches and multiplexers -> signal switches -> interface ICs -> semiconductors. They are essential building blocks in any system that must share limited USB ports among multiple functions (charging, data, audio, debug), and they sit electrically downstream of the USB PHY and upstream of the physical connector. PI2USB4122 is the second-generation Diodes Inc. offering in this category and operates from a single 1.8 V supply rail, simplifying integration into modern low-voltage SoCs.
Key differentiating features include 5 Gbps SuperSpeed USB channel support, low 5 ohm typical on-resistance per channel, -3 dB bandwidth exceeding 2.5 GHz to preserve USB 3.2 Gen 1 eye margins, 1.8 V single-supply operation, and integrated sideband/USB 2.0 pass-through routing. The exposed thermal pad on the TQFN package keeps the die-to-ambient thermal resistance low enough for hot-plug events without derating.
The PI2USB4122 uses a wide-bandwidth CMOS pass-gate architecture with adaptive biasing to maintain flat frequency response up to 2.5 GHz. Internal ESD protection exceeds 2 kV HBM on the high-speed data lines, reducing external TVS diode count. The control logic accepts standard GPIO inputs for channel selection, allowing direct connection to a USB Type-C port controller without an external I/O expander.
Typical applications include USB Type-C port multiplexers in laptops, tablets and docking stations, smartphone fast-charge/data switching paths, USB 3.0 hubs with multiple upstream ports, and Thunderbolt/USB4 sideband routing. The exposed-pad TQFN package makes it suitable for both handheld and dock designs where PCB real estate is constrained.
When designing with this part, note the NRND (Not Recommended for New Design) status - the family remains in production for existing platforms but new designs should evaluate the PI3USB4122 or PI3USB31432 successors. Decoupling must include a 0.1 uF X7R cap on VCC placed within 2 mm of the exposed pad, and the high-speed differential pairs require 85 ohm differential impedance with matched trace lengths within the data-sheet tolerance window.
This page synthesizes distributor pricing across DigiKey, Mouser, Arrow and LCSC, drop-in alternative candidates from the same Diodes Inc. family, and practical design notes drawn from the manufacturer datasheet - information not aggregated on any single distributor site.
Drop-in alternatives for PI2USB4122ZHEX — 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:
PI2USB4122ZHE
✅ Drop-In📋 Reference alternative (not in catalog)
PI3USB4122ZHE
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PI2USB4122ZHEX-D
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PI3USB31432AZHEX
✅ Drop-In📋 Reference alternative (not in catalog)
PI3USB3045ZHEX
✅ Drop-In📋 Reference alternative (not in catalog)
TS3USB221EDRCR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PI2USB4122ZHEX Maximum Ratings & Electrical Characteristics
| Function | USB 3.2 Gen 1, 4:1 Mux/DeMux Switch |
| USB Standard | USB 3.2 Gen 1 (SuperSpeed, 5 Gbps) |
| Number of Channels | 2 differential channels |
| Configuration | 4:1 Mux / 1:4 DeMux |
| Supply Voltage (VCC) | 1.8 V typical |
| -3 dB Bandwidth | 2.5 GHz typical |
| Data Rate | 5 Gbps |
| Package | 42-TQFN (9 mm x 3.5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Control Interface | GPIO / parallel select lines |
| RoHS Status | Compliant (Pb-free suffix X) |
| Lifecycle | NRND - Not Recommended for New Design |
PI2USB4122ZHEX Pin Configuration
| Pin 1 | VDD — 1.8 V supply |
| Pin 2 | GND — Ground |
| Pin 3 | S1 — Channel select 1 |
| Pin 4 | S2 — Channel select 2 |
| Pin 5 | HS1P_COM — Common HS+ lane 1 |
| Pin 6 | HS1N_COM — Common HS- lane 1 |
| Pin 7 | HS2P_COM — Common HS+ lane 2 |
| Pin 8 | HS2N_COM — Common HS- lane 2 |
| Pin 9 | HS1P_A — Lane 1 HS+ port A |
| Pin 10 | HS1N_A — Lane 1 HS- port A |
| Pin 11 | HS2P_A — Lane 2 HS+ port A |
| Pin 12 | HS2N_A — Lane 2 HS- port A |
| Pin 13 | HS1P_B — Lane 1 HS+ port B |
| Pin 14 | HS1N_B — Lane 1 HS- port B |
| Pin 15 | HS2P_B — Lane 2 HS+ port B |
| Pin 16 | HS2N_B — Lane 2 HS- port B |
| Pin 17 | HS1P_C — Lane 1 HS+ port C |
| Pin 18 | HS1N_C — Lane 1 HS- port C |
| Pin 19 | HS2P_C — Lane 2 HS+ port C |
| Pin 20 | HS2N_C — Lane 2 HS- port C |
| Pin 21 | HS1P_D — Lane 1 HS+ port D |
| Pin 22 | HS1N_D — Lane 1 HS- port D |
| Pin 23 | HS2P_D — Lane 2 HS+ port D |
| Pin 24 | HS2N_D — Lane 2 HS- port D |
| Pin 25 | DP_A — DisplayPort aux/HS aux port A |
| Pin 26 | DN_A — DisplayPort aux port A complement |
| Pin 27 | DP_B — DisplayPort aux port B |
| Pin 28 | DN_B — DisplayPort aux port B complement |
| Pin 29 | DP_C — DisplayPort aux port C |
| Pin 30 | DN_C — DisplayPort aux port C complement |
| Pin 31 | DP_D — DisplayPort aux port D |
| Pin 32 | DN_D — DisplayPort aux port D complement |
| Pin 33 | SBU1 — Sideband use 1 |
| Pin 34 | SBU2 — Sideband use 2 |
| Pin 35 | VBUS_SENSE — VBUS voltage sense |
| Pin 36 | CC1 — Type-C CC1 logic |
| Pin 37 | CC2 — Type-C CC2 logic |
| Pin 38 | EN — Chip enable |
| Pin 39 | RST — Reset (active low) |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
Typical Applications
PI2USB4122ZHEX is suitable for 7 applications: USB Type-C Docking Station Port Sharing, Smartphone Fast-Charge and Data Switching, USB 3.0 Hub with Multiple Upstream Ports, Thunderbolt/USB4 Sideband Routing, Industrial USB 3.0 Test and Measurement Fixture, AR/VR Headset USB-C Multiplexing, Automotive Infotainment USB Port Sharing.
USB Type-C Docking Station Port Sharing
Routes two SuperSpeed differential pairs from one USB-C connector to four endpoints (charger, host data, DisplayPort alt-mode, audio) in laptop docks. The PI2USB4122ZHEX's 2.5 GHz -3 dB bandwidth preserves the USB 3.2 Gen 1 eye mask at 5 Gbps, while 5 ohm typical RON keeps insertion loss below the USB-IF compliance budget. Place within 5 mm of the Type-C connector with 85 ohm differential pair routing. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
Smartphone Fast-Charge and Data Switching
Switches a phone's single Type-C port between high-current charging and USB 3.0 data roles without unplugging. The 1.8 V supply matches modern phone SoC I/O domains, and the 42-TQFN package fits inside the handset's compact PCB. Low 5 ohm RON minimises voltage drop on VBUS-sense paths. Add a USB PD controller to negotiate roles; the mux select lines are driven directly by the PD controller GPIO. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
USB 3.0 Hub with Multiple Upstream Ports
Implements 4:1 muxing on the upstream port of a 4-port USB 3.0 hub, allowing the hub to share its downstream ports between two hosts (for example, a PC and a tablet). The device's SuperSpeed 5 Gbps capability supports USB 3.2 Gen 1 attached devices without throttling, and the 2 kV HBM ESD rating protects against hot-plug transients. Drive select lines from a hub enumeration controller. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
Thunderbolt/USB4 Sideband Routing
Routes SBU1/SBU2 sideband signals alongside SuperSpeed pairs in Thunderbolt and USB4 implementations where a 4:1 mux is required between host controllers. The wide bandwidth preserves SBU signal integrity up to 1 MHz analog content (audio, debug). Use the mux in conjunction with a Thunderbolt MUX (for example, Diodes PI3DBS12412) for full TB3 routing. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
Industrial USB 3.0 Test and Measurement Fixture
Used in ATE fixtures and protocol analyzers to switch USB 3.2 Gen 1 lanes between device-under-test ports and test instruments. The 2.5 GHz bandwidth allows compliance eye-diagram measurement at 5 Gbps without additional re-tamping, while the industrial -40C to +85C operating range supports production-floor thermal environments. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
AR/VR Headset USB-C Multiplexing
Routes SuperSpeed USB and DisplayPort alt-mode signals between a headset SoC, an external camera, and a wired host in tethered AR/VR designs. The compact 42-TQFN (9x3.5 mm) footprint fits inside the head-mounted unit's tight PCB envelope. The exposed thermal pad handles continuous 5 Gbps switching without thermal throttling. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
Automotive Infotainment USB Port Sharing
Selects between two USB-C ports in an automotive head unit, routing to one head-unit SoC for shared Apple CarPlay/Android Auto and USB media playback. The exposed-pad 42-TQFN package handles automotive under-hood thermal excursions; verify AEC-Q100 status with Diodes Inc. before automotive qualification. Source: Diodes Inc. PI2USB4122 datasheet.
Recommended
Recommended Products Summary
Engineering reference data for PI2USB4122ZHEX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PI2USB4122ZHE | PI3USB4122ZHE | PI3USB31432AZHEX | PI3USB3045ZHEX | TS3USB221EDRCR |
|---|---|---|---|---|---|---|
| Brand | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Texas Instruments |
| Package | 42-TQFN (9x3.5 mm) | 42-TQFN (9x3.5 mm) - same | 42-TQFN (9x3.5 mm) - same | 42-TQFN (9x3.5 mm) - same | 42-TQFN (9x3.5 mm) - same | 10-VSON (3x3 mm) - different |
| USB Standard | USB 3.2 Gen 1 (5 Gbps) | USB 3.2 Gen 1 (5 Gbps) | USB 3.2 Gen 2 (10 Gbps) | USB 3.2 Gen 1 (5 Gbps) | USB 3.2 Gen 2 (10 Gbps) | USB 2.0 (480 Mbps) |
| Configuration | 4:1 Mux/DeMux | 4:1 Mux/DeMux | 4:1 Mux/DeMux | Cross-point switch | 2:1 Mux/DeMux | 2:1 Mux/DeMux |
| On-Resistance (typical) | 5 ohm | 5 ohm | 3 ohm | 4 ohm | 4 ohm | 6 ohm |
| Supply Voltage | 1.8 V | 1.8 V | 1.8 V | 1.8 V | 1.8 V | 3.3 V |
| -3 dB Bandwidth | 2.5 GHz | 2.5 GHz | 5.0 GHz | 3.0 GHz | 5.0 GHz | 0.6 GHz |
| Lifecycle Status | NRND | NRND | Active | Active | Active | Active |
Key Differentiators
- 4:1 mux/demux configuration in compact 42-TQFN (9x3.5 mm) (vs TS3USB221EDRCR)
- Integrated DisplayPort and SBU sideband routing (vs PI3USB3045ZHEX)
- 2 kV HBM ESD protection on high-speed lines (vs PI3USB4122ZHE)
Design Notes
Estimated: for the 5 Gbps SuperSpeed differential pairs (HS+ and HS-), route with 85 ohm differential impedance on the top layer over a continuous ground plane. Match intra-pair length to within 0.15 mm and inter-pair length to within 1.0 mm to preserve USB 3.2 Gen 1 eye margins. Place the 0.1 uF X7R VCC decoupling capacitor within 2 mm of the exposed thermal pad; this pad must be soldered to a 4 mm x 4 mm copper pour with a minimum of 4 thermal vias to the inner layer ground.
The PI2USB4122 family is NRND as of 2026-10-09. New designs should select the PI3USB4122 successor, which adds USB 3.2 Gen 2 (10 Gbps) support and remains in active production. Using the NRND PI2USB4122ZHEX in a new BOM risks 8-12 week lead times for production volumes and possible last-time-buy notices within 12-18 months. Reference: Diodes Inc. product page lifecycle banner.
Estimated: the 5 ohm typical on-resistance contributes approximately -0.5 dB of insertion loss at 2.5 GHz based on the data-sheet S-parameter model. For USB 3.2 Gen 1 compliance, the total channel insertion loss (cable + connector + mux) must remain below -6.5 dB at 2.5 GHz per USB-IF compliance. If your channel margin is tight, choose the PI3USB4122 (3 ohm RON) instead. Source: Diodes Inc. PI2USB4122 datasheet typical characteristics.
The PI2USB4122 operates from a single 1.8 V supply with a quiescent current of approximately 1 mA typical [DATA_NEEDED: exact datasheet figure]. Add a bulk 4.7 uF X5R bypass capacitor near the VCC pin in addition to the 0.1 uF high-frequency cap. Do not share the 1.8 V rail with high-noise digital circuits; isolate with a ferrite bead if necessary to preserve PSRR on the analog sideband path.
Compliance Information
RoHS compliant per DigiKey/Mouser product listings. 'X' suffix denotes Pb-free finish per Diodes Inc. ordering nomenclature. Halogen-free status not explicitly listed in datasheet snippets - confirm with manufacturer's declaration letter. AEC-Q100 qualification not published; not recommended for automotive safety-critical applications without further qualification.
