YURUNOX · USB 2.0 signal-chain selection and sourcing
TUSB211 vs TUSB214: Key Differences
TUSB211 is the simpler AC-boost conditioner; TUSB214 adds selectable DC boost, I²C or strap configuration, and a BC1.2 Charging Downstream Port controller. They share a 12-pin, 1.6 × 1.6 mm X2QFN footprint and 3.0–3.6 V operating supply, but their control pins and reset defaults differ. Treat TUSB214 as a migration candidate—not an automatic drop-in replacement.
The answer in one minute
Both devices monitor one USB 2.0 D+/D− channel and condition only the 480 Mbps high-speed waveform. Low-speed and full-speed signaling pass without active compensation. Neither device is a USB hub, a PHY, a protocol repeater, a VBUS power switch, or a USB 3.x SuperSpeed redriver.
Choose TUSB211 when
An existing 3.3 V product is already qualified with resistor-selected AC boost and changing the device would create more validation cost than value.
Choose TUSB214 when
The high-speed eye needs AC and DC recovery, the port needs an integrated BC1.2 CDP controller, or configuration flexibility is worth the extra pin review.
Choose neither when
The failure is on SuperSpeed lanes, a USB 2.0 protocol problem, a gross routing defect, missing VBUS power control, or a new design better served by a newer TI generation.
Verified against the current TUSB211 product page, TUSB211 Rev. D datasheet, TUSB214 product page, and TUSB214 Rev. A datasheet. Review date: 28 August 2026.
TUSB211 vs TUSB214 side by side
| Decision field | TUSB211 / TUSB211I | TUSB214 / TUSB214I | Practical consequence |
|---|---|---|---|
| Signal correction | Four resistor-selected AC boost levels | Four AC boost levels plus nominal 40, 60, or 80 mV DC boost | TUSB214 can address reduced static amplitude as well as rounded high-frequency transitions |
| Charging function | Compatible with BC1.2 signaling; no CDP controller | Integrated BC1.2 Charging Downstream Port controller | TUSB214 can supply the data-line handshake when a host or hub lacks CDP, but not VBUS power |
| Configuration | EQ resistor sampled at power-up | Pin straps or 100 kHz I²C at address 0x2C | TUSB214 adds register tuning and status access; firmware and pull-ups become part of the design |
| EQ floating default | Minimum EQ | Maximum AC boost | An omitted resistor can reverse the intended default during migration |
| Cable positioning stated by TI | Product page describes 2 m cable redriving strength | Datasheet states up to 5 m pre-channel or 2 m post-channel | These are test-context indicators, not universal cable guarantees |
| Supply | 3.0–3.6 V recommended, 3.3 V nominal | 3.0–3.6 V recommended, 3.3 V nominal | Do not connect either device directly to a 5 V rail |
| Package | 12-pin RWB X2QFN, 1.6 × 1.6 mm | 12-pin RWB X2QFN, 1.6 × 1.6 mm | Footprint reuse is possible; control-pin behavior still requires review |
| Temperature versions | TUSB211: 0–70°C; TUSB211I: −40–85°C ambient | TUSB214: 0–70°C; TUSB214I: −40–85°C ambient | Quote the full orderable part; the base name alone does not preserve grade |
| Lifecycle position | Not recommended for new designs; TI points to TUSB211A | Active; TI lists newer TUSB216/TUSB216I options | Legacy availability and new-platform suitability are different questions |
On a narrow screen, scroll the table horizontally. Electrical limits and settings above come from the cited TI documents; confirm the current orderable addendum before release or purchase.
What a USB 2.0 signal conditioner fixes—and what it cannot
Loss in a USB 2.0 channel has more than one visible symptom. Capacitive loading and limited bandwidth round the edges and increase inter-symbol interference. Resistive and distributed loss can reduce differential amplitude. Connectors, switches, common-mode chokes, ESD protectors, test pads, vias, long PCB traces, and cable gauge all contribute to the complete result.
Simplified signal path
The conditioner can be placed before or after the dominant loss. Its flow-through footprint keeps D+/D− continuity when the part is unpowered or unpopulated, provided the PCB is routed as TI recommends.
AC boost sharpens transitions
AC boost emphasizes high-frequency content. It can improve the edge rate and open an eye closed by bandwidth loss. It cannot guarantee a better result at every setting: too much boost may create overshoot, ringing, crossover distortion, or another mask violation. TUSB211 gives four AC-boost levels through an EQ pull-down resistor.
DC boost restores static differential amplitude
TUSB214 adds a nominal 40, 60, or 80 mV DC boost. In non-I²C mode, pin 9 is a tri-level DC_BOOST input during reset: pulled low selects 40 mV, floating selects 60 mV, and pulled high selects 80 mV. After reset it becomes the ENA_HS status output. That dual role is a real schematic constraint, not a naming detail.
An open eye is evidence, not the whole approval
A single attractive oscilloscope image can hide the cable, fixture, transmitter, measurement point, temperature, voltage, boost setting, and test mode that produced it. Record those conditions and repeat at channel corners.
The finished product still needs attach, detach, reset, suspend/resume, low-speed, full-speed, high-speed, interoperability, charging behavior where applicable, and compliance-oriented testing.
Pin compatibility: four checks before a migration
The two parts share supply, ground, reset, VREG, EQ, and D+/D− locations. The apparent mechanical match is useful, but a safe migration review must trace the actual nets connected to the multifunction pins.
| Pin | TUSB211 | TUSB214 | Migration question |
|---|---|---|---|
| 3 | TEST input; leave floating | SDA in I²C mode; reserved for TI test in non-I²C mode | Will a pull-up intentionally select I²C, or must this node remain isolated? |
| 4 | CD output | SCL in I²C mode; CD output in non-I²C mode | Could the existing CD load conflict with an I²C pull-up or controller clock? |
| 6 | EQ resistor; sampled at power-up; floating = minimum | EQ resistor; sampled when RSTN deasserts; floating = maximum AC boost | Is a defined resistor populated and revalidated? |
| 9 | ENA_HS output | DC_BOOST input during reset, then ENA_HS output in non-I²C mode | Can the legacy load coexist with a 22–47 kΩ strap and later output operation? |
| 11 | 1.8 V VREG output; 0.1 µF capacitor required | Same core-regulator function and capacitor requirement | Has anyone incorrectly used VREG as a general supply rail? |
Illustrative migration scenario · not a reported customer result
A legacy board left EQ open to get the TUSB211 minimum setting
The same assembly fitted with TUSB214 would sample a floating EQ as maximum AC boost. Even if every package pad aligns, the signal-conditioning state has changed before a single firmware line runs. The controlled response is to populate a deliberate EQ resistor, define pin 9 at reset, check whether I²C or non-I²C mode is intended, and rerun the complete electrical and interoperability plan.
Documented TI case: what “up to 5 m” actually means
Official datasheet example · not a YURUNOX laboratory claim
TUSB214 shows different results for pre-channel and post-channel placement
TI's TUSB214 datasheet includes high-speed eye examples for a 2 m cable used as post-channel loss and a 5 m cable used as pre-channel loss, each shown without and with the conditioner. TI also states “up to 5 m pre-channel or 2 m post-channel cable length” in the device features. The important lesson is not that every 5 m cable passes—it is that the conditioner’s location relative to the loss and measurement point changes the result.
“Pre-channel” means the conditioner strengthens the signal before it traverses the main cable loss. “Post-channel” means it acts after that loss, nearer the downstream measurement or receiver. Host transmitter quality, device receiver margin, cable gauge, connector count, PCB insertion loss, protection capacitance, test fixture, and boost settings remain part of the outcome.
| Evidence | Safe conclusion | Unsafe conclusion | Required next step |
|---|---|---|---|
| 2 m post-channel eye | TUSB214 can improve the shown TI setup under its documented conditions | Every 2 m assembled product will pass at any setting | Repeat with the product's own channel, fixtures, and worst-case parts |
| 5 m pre-channel eye | Placement before cable loss can support a longer tested channel | 5 m is a guaranteed system specification independent of wire gauge and PCB loss | Measure insertion loss or eye performance and validate required cable SKUs |
| Four AC + three DC settings | The device offers controlled tuning dimensions | Maximum AC and maximum DC are automatically best | Move one step at a time and retain the lowest passing configuration |
Primary evidence: TUSB214 datasheet, Figures 2–5 and feature description. The document's lab curves are manufacturer evidence for that setup, not a certification of a buyer's finished product.
Layout, tuning, and validation workflow
Start with the channel, not the gain setting
TI's 2026 layout guide lists 90 Ω ±15% differential and 45 Ω ±15% single-ended impedance for USB 2.0. It also says no AC-coupling capacitors and no polarity reversal on D+/D−. Keep the pair short, symmetric, and referenced to continuous ground.
Route D1P to D2P and D1M to D2M beneath the flow-through package. Avoid test-point stubs, unnecessary vias, split reference planes, high-capacitance protection, and abrupt geometry changes. Put the external ESD device close to the connector with an effective return path.
- Capture the baseline.Measure the unconditioned path or the lowest practical boost at the exact near-end and far-end points used for the decision.
- Name the failing mechanism.Separate low amplitude, slow edges, excessive jitter, overshoot, crossover, receiver sensitivity, attach/reset problems, and charging-port behavior.
- Tune AC boost first.Increase one EQ level at a time. Record resistor value, test setup, eye, rise/fall behavior, overshoot, and jitter.
- Add only the DC boost needed.On TUSB214, choose 40, 60, or 80 mV from measurement—not from cable length alone.
- Exercise all USB 2.0 modes.Test detach/attach, reset, suspend/resume, low speed, full speed, high speed, OTG behavior if used, and CDP detection if TUSB214 provides it.
- Test corners.Use the longest and shortest approved cables, supply tolerance, temperature range, representative hosts/devices, and worst-case ESD/EMI components.
- Run compliance-oriented testing.Use the applicable USB-IF electrical procedure, approved fixtures, and a capable laboratory method. A datasheet plot is not a finished-product pass.
- Freeze production evidence.Store the resistor/strap values or I²C registers, reset timing, firmware revision, BOM alternatives, cable list, lab evidence, and requalification triggers.
Layout basis: TI's High-Speed Layout Guidelines for Signal Conditioners and USB Hubs, Rev. A, plus the device-specific layout sections in both datasheets.
Selection aid: turn channel symptoms into a review path
This tool organizes the next engineering decision. It does not simulate the channel, approve a substitution, or guarantee USB compliance.
Keep TUSB211 under the existing qualification
- Do not trigger a migration without a measured problem or lifecycle requirement.
- Confirm the exact TUSB211/TUSB211I orderable part, temperature grade, reel, and lifecycle plan.
- Pre-approve a validated alternate instead of making an emergency footprint-only substitution.
Planning output only. Final selection requires current datasheets, schematic review, measurement, and system qualification.
Purchasing controls: buy the configuration, not the family name
YURUNOX is an independent electronic-component sourcing partner, not the manufacturer of TUSB211 or TUSB214. TI's current datasheets and orderable addenda remain the technical and packaging authority. A useful sourcing review connects the engineering configuration to the exact orderable part and its supply evidence.
Illustrative procurement scenario · not a shipment claim
A supplier offers TUSB214 as a “drop-in” answer to a TUSB211 shortage
Before price approval, engineering checks pins 3, 4, 6, and 9, confirms the 3.3 V rail, decides whether CDP is acceptable, defines I²C or strap mode, and creates a new test plan. Procurement then requests the exact commercial or industrial orderable part, reel quantity, date/lot limits, manufacturer traceability, packaging condition, lifecycle confirmation, and quality documentation. The decision consequence is clear: footprint similarity can reduce PCB rework, but it does not eliminate requalification.
RFQ fields that prevent avoidable rework
- Exact manufacturer part number.Specify TUSB211 versus TUSB211I or TUSB214 versus TUSB214I, the complete orderable suffix, package/carrier, and required temperature grade.
- Port architecture.State host, hub, or device side; connector type; USB 2.0-only or combined USB 3.x/Type-C path; OTG use; and whether another IC already implements CDP or DCP behavior.
- Channel evidence.Provide PCB length/stack-up, connector count, cable SKU and length, ESD/EMI components, switches, the failing test point, and available eye or insertion-loss data.
- Configuration.Record EQ resistor, TUSB214 DC-boost strap, I²C use/address ownership, reset circuit, VREG capacitor, CD/ENA_HS loading, and firmware register settings.
- Qualification boundary.List approved hosts/devices, voltage and temperature corners, cable set, compliance target, and which changes force retest.
- Supply evidence.Request current status, manufacturer traceability, lot/date requirements, label and packing photos where appropriate, moisture/handling data, inspection scope, change notification, and sample quantity.
For sourcing controls and evidence categories, see YURUNOX's quality assurance overview. For manufacturer-family support, see the Texas Instruments sourcing page. These links describe sourcing support; they do not replace TI design documents.
Frequently asked questions
Is TUSB214 a direct replacement for TUSB211?
No. It is a plausible migration candidate because the package, supply range, and D+/D− locations align, but the control pins and behavior differ. Review SDA/SCL mode entry, pin 9's reset strap/output role, the opposite EQ floating default, and integrated CDP behavior; then retune and requalify the channel.
What is the biggest electrical difference?
TUSB211 provides AC boost only. TUSB214 provides AC boost plus a selectable nominal 40, 60, or 80 mV DC boost. AC boost sharpens transitions; DC boost raises the static differential level when channel loss reduces amplitude.
Does TUSB211 support BC1.2 charging?
It is compatible with BC1.2 signaling in the sense that the conditioner does not block the protocol, but it does not implement a Charging Downstream Port controller. TUSB214 adds that CDP data-line function.
Does TUSB214 supply charging current?
No. It performs CDP signaling on D+ and D−. The platform still needs a compliant 5 V VBUS source, power switch or current limiting, fault handling, connector protection, and thermal design.
Can either part repair low-speed or full-speed signaling?
No active compensation is applied to USB low-speed or full-speed signals. If those modes fail, investigate routing, polarity, pull-ups, protection capacitance, grounding, VBUS, reset timing, CDP interaction, cable quality, and protocol behavior.
Which part supports a longer cable?
TI positions TUSB214 for a higher-loss channel and documents up to 5 m pre-channel or 2 m post-channel in its own setup. Cable length alone is not a selection rule; wire gauge, PCB loss, connector count, protection, placement, transmitter, receiver, and boost setting all matter.
Do TUSB211 and TUSB214 require 3.3 V?
Both specify 3.0–3.6 V recommended operation with 3.3 V nominal. If the design only has 5 V or needs a wider rail, compare a newer compatible device such as TUSB211A or another current family member against the exact feature set.
Which device is the better choice for a new design?
Do not default to TUSB211 because TI marks it not recommended for new designs. TUSB214 remains active when integrated CDP and second-generation compensation fit the port. Also compare TUSB211A, TUSB216/TUSB216I, and TUSB217A for lifecycle, supply, charging-controller, and signal-margin requirements.
Evidence-first sourcing support
Send the channel conditions, not only “TUSB211 or TUSB214”
Share the exact part, USB topology, supply, cable and PCB path, protection components, measured failure, CDP requirement, configuration plan, quantity, and traceability needs. That gives engineering and procurement a reviewable starting point.
Request a part and evidence review- Exact orderable part and allowed alternates
- Commercial or industrial temperature grade
- EQ, DC boost, I²C, and reset configuration
- Channel/cable conditions and test evidence
- Quantity, packaging, lot/date, and traceability
Primary technical sources and image credits
- Texas Instruments — TUSB211 product page: current NRND status, TUSB211A direction, package, channel, and product features.
- Texas Instruments — TUSB211/TUSB211I datasheet, Rev. D: pin functions, 3.0–3.6 V operation, EQ sampling/default, temperature variants, application curves, and flow-through layout.
- Texas Instruments — TUSB214 product page: active status, integrated CDP, AC/DC boost, configuration, cable positioning, package, and newer alternatives.
- Texas Instruments — TUSB214/TUSB214I datasheet, Rev. A: pin functions, I²C entry/address, EQ default, DC-boost levels, CDP behavior, operating conditions, and documented eye examples.
- Texas Instruments — TUSB2XX Implementation Guide: family positioning, placement, tuning, and implementation context.
- Texas Instruments — High-Speed Layout Guidelines for Signal Conditioners and USB Hubs, Rev. A: USB 2.0 impedance, coupling, polarity, return path, symmetry, via, stub, connector, and ESD/EMI guidance.
- Images: USB connector types (public domain), generic eye diagram (public domain), and PCB close-up (CC0), all via Wikimedia Commons.
Technical review date: 28 August 2026. Product status, documentation, orderable parts, and compliance procedures can change; reconfirm them before schematic release, alternate approval, or purchase. The examples labeled illustrative are decision models, not YURUNOX customer results, laboratory tests, shipments, or first-hand performance claims.