HD3SS3212IRKSR - 10Gbps USB 3.1 Type-C 2:1 Mux | TI
MPN: HD3SS3212IRKSR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.96 | $0.96 |
| 10 | $0.86 | $8.60 |
| 100 | $0.75 | $75.00 |
| 500 | $0.65 | $325.00 |
| 1,000 | $0.55 | $550.00 |
HD3SS3212IRKSR Overview
What is a passive differential mux? A passive differential multiplexer/demultiplexer is an analog switch that routes high-speed differential pairs without active redriver or retimer circuitry. Unlike a redriver, a passive mux introduces only insertion loss and a small amount of return-loss variation - it does not restore signal amplitude. This makes passive muxes ideal for short-reach intra-chassis routing where the channel loss budget is already met, but problematic for long cables or lossy connectors. The HD3SS3212 sits in the signal-chain hierarchy between the USB-C receptacle and the host/device PHY: PHY -> redriver (optional) -> mux/demux -> connector.
Key features include 10 Gbps differential signal bandwidth, low on-resistance (Ron) of typically 5 ohm, -3 dB bandwidth above 7 GHz, ESD protection of 2 kV HBM on high-speed pins, and a flow-through pinout that simplifies PCB layout. The wide -3 dB bandwidth ensures signal-integrity margin for USB 3.1 Gen 2 compliance, while the flow-through pinout keeps TX and RX differential pairs on a straight horizontal trace, eliminating the need for vias in the high-speed path.
Architecture is built on TI's high-speed analog switch process, optimized for low capacitance (typically < 1.5 pF per channel) and minimal channel-to-channel skew. The device is bidirectional and symmetric - either side can act as the common port - which simplifies both mux and demux use cases. The SEL input is a standard CMOS logic pin with an internal pull-down, defaulting to Port B at power-up.
Typical applications include USB Type-C ports on laptops, tablets, and smartphones; docking stations; DisplayPort alt-mode adapters; Thunderbolt 3/4 accessory switches; and any platform that needs to share a USB-C connector between USB and a non-USB high-speed interface.
Design considerations: place the HD3SS3212 as close to the USB-C receptacle as possible to keep stub lengths below 200 mil. Use 90 ohm differential impedance with reference-grounded coplanar-waveguide routing, AC-couple the channels with 100 nF capacitors at the PHY side, and provide a clean 3.3 V rail decoupled with 0.1 µF + 1 µF ceramics.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, parametric comparison, and PCB-level design notes beyond the manufacturer datasheet.
Drop-in alternatives for HD3SS3212IRKSR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with HD3SS3212IRKSR (same form factor and footprint) — differing in Function, MSL Level, Maximum Data Rate, Number of Channels, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
HD3SS3212IRKST
✅ Drop-In📋 Reference alternative (not in catalog)
HD3SS3212IRKSRQ1
✅ Drop-In📋 Reference alternative (not in catalog)
HD3SS3212RKSR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
HD3SS3212RKST
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
HD3SS3212IRKSRG4
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
HD3SS3212IRKSR Specifications
| Function | 2-channel differential 2:1/1:2 mux/demux |
| Protocol | USB 3.1 Gen 1 / Gen 2, DisplayPort, PCIe |
| Maximum Data Rate | 10 Gbps per channel |
| Number of Channels | 2 differential |
| Supply Voltage | 3.0 V to 3.6 V |
| Quiescent Current (Iq) | 20 µA typical |
| On Resistance (Ron) | 5 ohm typical |
| Differential -3 dB Bandwidth | 7 GHz typical |
| Channel Capacitance | < 1.5 pF typical |
| ESD Protection (HBM) | 2 kV on high-speed pins |
| Control Input (SEL) | Active-high, internal pull-down, default Port B |
| Operating Temperature Range | -40C to +85C |
| Package | 20-pin VQFN (2.5x4.5 mm, RKS) |
| Mounting Type | Surface Mount |
| MSL Level | 2 (1 year floor life) |
| Lead-Free / RoHS | Yes / Compliant |
HD3SS3212IRKSR Pin Configuration
| Pin 1 | RX2P_A — Differential RX2 positive, Port A side |
| Pin 2 | RX2N_A — Differential RX2 negative, Port A side |
| Pin 3 | TX2P_A — Differential TX2 positive, Port A side |
| Pin 4 | TX2N_A — Differential TX2 negative, Port A side |
| Pin 5 | VCC — 3.3 V power supply |
| Pin 6 | GND — Ground |
| Pin 7 | RX1P_A — Differential RX1 positive, Port A side |
| Pin 8 | RX1N_A — Differential RX1 negative, Port A side |
| Pin 9 | TX1P_A — Differential TX1 positive, Port A side |
| Pin 10 | TX1N_A — Differential TX1 negative, Port A side |
| Pin 11 | RX1P_B — Differential RX1 positive, Port B side |
| Pin 12 | RX1N_B — Differential RX1 negative, Port B side |
| Pin 13 | TX1P_B — Differential TX1 positive, Port B side |
| Pin 14 | TX1N_B — Differential TX1 negative, Port B side |
| Pin 15 | RX2P_B — Differential RX2 positive, Port B side |
| Pin 16 | RX2N_B — Differential RX2 negative, Port B side |
| Pin 17 | TX2P_B — Differential TX2 positive, Port B side |
| Pin 18 | TX2N_B — Differential TX2 negative, Port B side |
| Pin 19 | SEL — Channel select (0 = Port A-Port B, 1 = Port A-Port C) |
| Pin 20 | EN — Device enable (active high, internal pull-down); tied to VCC if unused |
Typical Applications
HD3SS3212IRKSR is suitable for 6 applications: USB Type-C Laptop / Tablet Port, USB-C Docking Station, Smartphone USB-C Port with DP Alt-Mode, Industrial Embedded Board USB-C, Thunderbolt 3 / USB4 Accessory, External SSD Enclosure (USB 3.2 Gen 2).
USB Type-C Laptop / Tablet Port
The HD3SS3212IRKSR's 10 Gbps per-channel bandwidth and 7 GHz -3 dB bandwidth make it ideal for USB Type-C ports on laptops, tablets, and 2-in-1 PCs that need to toggle high-speed lanes between a USB 3.1 host PHY and a DisplayPort or Thunderbolt alternate-mode accessory. With a flow-through RKS-20 (2.5x4.5 mm) pinout, TX/RX pairs run straight from the USB-C receptacle through the mux to the PHY, keeping stub lengths below 200 mil and avoiding vias in the high-speed path. The 5 ohm Ron and < 1.5 pF C_on preserve the 90 ohm differential impedance profile needed for Gen 2 signal-integrity compliance, while the 20 µA quiescent current has negligible impact on battery life. Source: TI HD3SS3212 datasheet and SLLA481 schematic checklist.
Recommended
USB-C Docking Station
Inside a USB-C docking station, the HD3SS3212IRKSR sits between the upstream USB-C connector and the downstream USB 3.1 hub + DisplayPort splitter, switching lane routing based on whether the attached host is in USB-only or DP-alt-mode. The 10 Gbps / channel capability supports simultaneous USB 3.1 Gen 2 + 4K DP 1.4 traffic, while the bidirectional mux lets the same silicon work for both upstream-facing and downstream-facing ports. The RKS-20 2.5x4.5 mm VQFN footprint allows dense placement near the connector, and 2 kV HBM ESD on the high-speed pins lets the dock survive hot-plug events without external TVS arrays. Power dissipation is negligible at 20 µA Iq, so no thermal relief is needed.
Recommended
Smartphone USB-C Port with DP Alt-Mode
Smartphones that output DisplayPort over USB-C need a 2:1 mux to share the high-speed lanes between the USB 3.1 device PHY and the DP 1.4 transmitter. The HD3SS3212IRKSR's 10 Gbps bandwidth comfortably carries DP 1.4 HBR3 at 8.1 Gbps per lane, while its 1.5 pF C_on preserves the eye diagram at the Type-C connector. The 2.5x4.5 mm RKS-20 footprint occupies ~5 mm x 4.5 mm of board area, fitting inside the slim bezel of a modern smartphone PCB. Operating from -40C to +85C covers all smartphone thermal envelopes, and the 20 µA Iq is invisible against the phone's multi-hundred-mAh battery.
Recommended
Industrial Embedded Board USB-C
Industrial single-board computers and edge-AI boxes increasingly expose USB Type-C for both data and DisplayPort alt-mode. The HD3SS3212IRKSR's industrial -40C to +85C rating makes it suitable for factory-floor and outdoor enclosures, while the AEC-Q100 sibling (HD3SS3212IRKSRQ1) handles automotive embedded designs. The 10 Gbps / 7 GHz bandwidth supports simultaneous USB 3.1 Gen 2 storage and 4K display output over a single USB-C cable, and the 2 kV HBM ESD on the high-speed pins adds robustness in electrically noisy industrial environments. The flow-through pinout simplifies PCB layout reviews for cost-sensitive industrial designs.
Recommended
Thunderbolt 3 / USB4 Accessory
Thunderbolt 3 (10.3125 Gbps) and USB4 share the same physical layer as USB 3.1 Gen 2, and the HD3SS3212IRKSR's 7 GHz -3 dB bandwidth comfortably passes the TB3 dual-protocol bitstream. In a TB3 dock or hub, the mux toggles the USB-C high-speed lanes between a downstream host port and an upstream device PHY. The < 1.5 pF C_on is critical for maintaining the 90 ohm differential impedance profile required by the TB3 electrical spec, and the 5 ohm Ron adds minimal insertion loss (typically < 1 dB at 5 GHz). The RKS-20 2.5x4.5 mm VQFN footprint integrates cleanly into TB3 access card designs.
Recommended
External SSD Enclosure (USB 3.2 Gen 2)
External NVMe SSD enclosures that connect via USB-C use the HD3SS3212IRKSR to switch between USB 3.2 Gen 2x1 (10 Gbps) and USB 3.2 Gen 1 (5 Gbps) data rates. Although the mux does not change data rates itself, the same switch can be used to route the upstream USB-C lanes to two different PHY/bridge chips (e.g., a Realtek RTL9210B for Gen 2 and a JMS583 for Gen 1). The 10 Gbps per channel bandwidth preserves the Gen 2x1 throughput, while the 5 ohm Ron and low C_on preserve signal-integrity across the USB-C cable assembly. The RKS-20 2.5x4.5 mm VQFN package fits in the tight enclosure PCB of a portable SSD.
Recommended
Recommended Products Summary
Engineering reference data for HD3SS3212IRKSR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | HD3SS3212IRKST | HD3SS3212IRKSRQ1 | HD3SS3212RKSR | HD3SS3212RKST | HD3SS3212IRKSRG4 |
|---|---|---|---|---|---|---|
| Package | 20-VQFN (2.5x4.5 mm, RKS) | 20-VQFN (2.5x4.5 mm, RKS) - same | 20-VQFN (2.5x4.5 mm, RKS) - same | 20-VQFN (2.5x4.5 mm, RKS) - same | 20-VQFN (2.5x4.5 mm, RKS) - same | 20-VQFN (2.5x4.5 mm, RKS) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Maximum Data Rate | 10 Gbps | 10 Gbps | 10 Gbps | 10 Gbps | 10 Gbps | 10 Gbps |
| Channels | 2 differential | 2 differential | 2 differential | 2 differential | 2 differential | 2 differential |
| AEC-Q100 Qualification | No | No | Yes (AEC-Q100) | No | No | No |
| Carrier Quantity | 3000 (7" reel) | 250 (cut tape / 7" reel) | 3000 (7" reel) | 3000 (7" reel) | 250 (cut tape) | 3000 (7" reel) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +105C (AEC-Q100) | -40C to +85C | -40C to +85C | -40C to +85C |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V |
| Quiescent Current | 20 µA typical | 20 µA typical | 20 µA typical | 20 µA typical | 20 µA typical | 20 µA typical |
Key Differentiators
- Only TI USB 3.1 Gen 2 mux in the 2.5x4.5 mm RKS-20 package with full AEC-Q100 option (vs HD3SS3212IRKST)
- Flow-through pinout eliminates vias in the high-speed path (vs HD3SS215IRTQT)
- Wider -3 dB bandwidth than the HD3SS215 predecessor (vs HD3SS215IRTQT)
Design Notes
Place the HD3SS3212IRKSR as close as physically possible to the USB Type-C receptacle. The flow-through RKS-20 (2.5x4.5 mm) pinout is designed for straight-trace routing - TX/RX pairs enter one side and exit the opposite side without vias. Keep stub lengths below 200 mil to avoid reflections at 5 GHz. Use 90 ohm differential impedance with a grounded coplanar-waveguide stack-up and 100 nF AC-coupling caps on each differential pair at the PHY side.
Power the HD3SS3212IRKSR from a clean 3.3 V rail. Place a 1 µF X7R ceramic bulk capacitor + a 0.1 µF X7R decoupling capacitor within 1 mm of the VCC pin (pin 5). Ground the GND pin (pin 6) directly to the underlying ground plane with multiple vias. The 20 µA quiescent current means no thermal concerns, but a noisy VCC can couple into the high-speed channels through the parasitic on-resistance.
Always include 100 nF AC-coupling capacitors on every differential lane between the HD3SS3212 and the USB-C receptacle or PHY - USB 3.1 specification requires DC blocking at every receiver. Without these caps, low-frequency baseline wander can corrupt the receiver's decision feedback equalizer. Place the AC caps within 200 mil of the receptacle connector side for best return-loss performance. Maintain 90 ohm differential impedance across each cap footprint.
Do not float the SEL pin (pin 19). Although it has an internal pull-down defaulting to Port B, leaving SEL floating can cause oscillation during hot-plug events when the USB-C CC pins toggle. Drive SEL directly from a GPIO or a logic buffer. Similarly, do not leave EN (pin 20) floating - tie it to VCC for always-on operation or to a GPIO for low-power shutdown. Both pins are 3.3 V CMOS logic, not 1.8 V tolerant.
Compliance Information
Standard HD3SS3212IRKSR is RoHS/REACH compliant and lead-free (Pb-free RKS package). Not AEC-Q100 qualified - choose HD3SS3212IRKSRQ1 for automotive designs. Conflict-mineral compliance per TI supply chain policy.
