TVS Diode for CAN: PESD2CAN,215 Selection & Layout

Nov 2,2025

Should you still design in PESD2CAN,215 or migrate now?

When you design a CAN or CAN-FD interface, one small diode quietly decides your compliance margin — the TVS diode. For years, engineers have trusted Nexperia’s PESD2CAN,215, a compact SOT-23 dual-line transient voltage suppressor built specifically for automotive CAN nodes. Yet, like many reliable workhorses, it now carries a note you can’t ignore: “Not Recommended for New Design (NRND).”

That NRND status doesn’t mean failure — it means lifecycle caution. Distributors like Mouser and Farnell still stock it in tape-and-reel (TR/CT) packaging, but Nexperia’s own product status flags the part as nearing its retirement phase. If you’re locking a new PCB layout for 2025 or later, you’ll need to think about supply continuity. Once production inventory drains, sourcing becomes inconsistent, and automotive PPAP compliance might become difficult.

Still, why do so many engineers hold onto it? The PESD2CAN,215 offers a practical mix of numbers that just work:

Reverse stand-off voltage (VRWM): 24 V
Breakdown voltage (VBR): ≥ 26.2 V
Clamping voltage (VC): ~41 V at 5 A (8/20 µs pulse)
Capacitance (Cp): ~25 pF @ 1 MHz
AEC-Q101 qualified, with a –55 °C to +150 °C operating range.

That balance—low enough capacitance for standard CAN and CAN-FD up to 2 Mbps, high enough surge rating for ±30 kV contact discharge (IEC 61000-4-2)—has kept this diode relevant.

Lifecycle & Risk Note

Nexperia’s latest PCNs confirm several packaging updates (SOT-23 tape material, label format, and resin hardener changes between 2020–2024). These don’t alter performance but indicate an aging product line being phased for next-gen alternatives. In short, it’s still safe for sustaining projects, but for new designs, plan your second source early — more on that later in this guide.

Internal reference: for readers exploring other protection parts, see TEJTE’s ESD protection collection — it provides guidance on automotive-grade layout and surge compliance.

Which TVS diode specs actually matter for CAN/CAN-FD?

When selecting a transient voltage suppressor, datasheet tables often blur together — 24 V here, 230 W there, a few picofarads sprinkled in. But for CAN and CAN-FD, only a few parameters genuinely drive reliability:

Mapping the key specs

Parameter	PESD2CAN,215 Typical	Design Impact
VRWM (Reverse Stand-Off Voltage)	24 V	Must exceed normal bus common-mode (±12 V typical, 24 V max).
VBR (Breakdown Voltage)	≥ 26.2 V	Ensures quick response to ±30 kV contact ESD pulses.
VC (Clamping Voltage @ 5 A, 8/20 μs)	≤ 41 V	Must stay below CAN transceiver's absolute max rating (often ±58 V).
Cp (Capacitance @ 1 MHz)	25 pF	Limits data rate: acceptable for classic CAN, borderline for >5 Mbps CAN-FD.
AEC-Q101 Qualified	Yes	Required for automotive compliance.
Operating Range	-55 °C ~ +150 °C	Guarantees stability across ECU temperature swing.

These four — VRWM, VC, Cp, and qualification — determine whether a diode is actually compatible with your CAN transceiver’s absolute max voltage and data-rate margin.

In short:

Too low VRWM, and you’ll clamp normal signals.
Too high VC, and you’ll burn the transceiver pins.
Too high Cp, and your eye diagram collapses at 8–10 Mbps.

Regulatory Perspective

PESD2CAN,215 meets AEC-Q101 standards and passes IEC 61000-4-2 (up to ±30 kV contact). These two marks are the “language” of automotive EMC. AEC-Q101 ensures lot-to-lot reliability under temperature cycling, while IEC 61000-4-2 defines actual immunity to human-body ESD events.

For CAN systems operating on both 12 V and 24 V vehicles, a 24 V TVS diode comfortably covers both rails because the signal lines are differential and float near ground potential. You only need to make sure it’s not used on the power supply rail—that’s a different beast (load-dump protection).

If you want to cross-reference parts, distributors like Mouser Electronics list equivalents with similar 41 V clamp and 25 pF capacitance, such as Bourns CDSOT23-T24CAN-Q and ST ESDCAN24-2BLY. We’ll evaluate those replacements later.

Where should the CAN TVS sit—connector, transceiver, or both?

This is the single most common question on design forums — and the most misunderstood.

If you’ve ever seen a CAN transceiver fail during ESD testing, odds are the diode was physically too far from the connector. Every extra millimeter of copper trace adds inductance, and at nanosecond timescales, inductance turns into voltage overshoot:

ΔV ≈ L × di/dt

1. The connector-side rule

Place the TVS diode as close to the CAN connector pins (CANH, CANL) as possible — ideally within 3–5 mm. The goal is to route the surge energy to chassis ground before it reaches the transceiver.

A simple layout heuristic:

Keep the trace between the connector pin and the TVS shorter than 5 mm.
Use two or more ground vias right beside the diode pad to minimize equivalent series inductance (ESL).
Avoid routing under or around large copper gaps; continuous return paths matter more than via count.

2. Interaction with termination and chokes

Many CAN networks include a split termination (2 × 60 Ω + 4.7 nF to ground) and a common-mode choke (CMC) right behind the connector. The TVS should sit ahead of the CMC — that way, it clamps surge energy before it couples through the choke and saturates it.

If you put the TVS after the choke, the energy sees a higher impedance path and might still arc across the transceiver. In contrast, placing it upfront ensures both lines see a symmetric clamp path.

At TEJTE, our own RF assemblies and ESD-rated connectors follow the same grounding philosophy — short paths, wide returns, and minimal via length. For a detailed look at physical examples, you can browse our connector layout practices.

How do you verify clamp safety for your transceiver?

You can’t design a CAN ESD protection diode in a vacuum — it has to play nicely with your transceiver’s absolute maximum ratings. For most 12 V/24 V automotive transceivers (e.g., TI SN65HVD230 or NXP TJA1049), the CANH/CANL pins can tolerate up to ±58 V transient relative to ground. That means your TVS diode’s clamping voltage (VC) under surge must stay below this ceiling.

Quick sanity check

Here’s a practical clamp check engineers use in real-world validation:

[ VC_{max} < V_{ABS_MAX(CANH/L)} ]

For the PESD2CAN,215,

VC(max) = 41 V @ 5 A (8/20 µs pulse)
Transceiver ABS MAX ≈ ±58 V

Result: safe. Even under full surge, the diode will protect without forward-biasing or overstressing the transceiver input cells.

Still, lab verification tells the full story. You can validate this using an IEC 61000-4-2 ESD gun (330 Ω/150 pF network) fired directly at the connector shield, while probing the CANH/CANL lines with a 500 MHz oscilloscope. Watch the voltage at the transceiver pins: the goal is to see a smooth clamp around 35–40 V without ringing above the absolute limit.

For engineers who also deal with RF or high-speed buses, the same principle applies: keep the return path tight and verify VC under realistic pulse energy, not just datasheet conditions.

For additional guidance on surge validation, see TEJTE’s IEC 61000-4-2 testing checklist, which details pulse shaping, contact discharge setup, and common lab pitfalls.

Can PESD2CAN,215 drop-in to CAN-FD or do you need lower Cp?

Here’s where things get tricky. The original PESD2CAN,215 was designed in an era when classical CAN topped out at 1 Mbps. Modern CAN-FD can reach 5–8 Mbps, sometimes even 10 Mbps in diagnostics mode. At those speeds, line capacitance (Cp) matters far more than surge rating.

The PESD2CAN,215’s 25 pF capacitance is fine for 1 Mbps, borderline for 2–3 Mbps, and too high for clean 8 Mbps edges — especially if you’re using long harnesses or additional filters.

When lower capacitance helps

Recent automotive TVS diodes have pushed Cp dramatically lower:

ROHM’s new CAN-FD protection parts reach ~3.5 pF while maintaining strong 26 V breakdown.
TI’s ESD2CANFD24-Q1 and ESD2CAN36-Q1 devices bring Cp down to 2.5–2.8 pF.
Bourns’ CDSOT23-T24C-Q stays under 10 pF, certified for CAN-FD.

With lower Cp, your signal rise/fall times stay sharper, your common-mode noise lower, and your eye diagram margin wider. The tradeoff is often slightly lower peak current rating, but for typical ESD events (±15 kV contact), these diodes easily pass IEC 61000-4-2 testing.

Signal-integrity sanity check

You can quickly estimate if your diode is “fast” enough using this rule of thumb:

[ f_{3dB} = \frac{1}{2\pi R_{line} C_p} ]

Assume 60 Ω per line and Cp = 25 pF → f₃dB ≈ 106 MHz, fine for ≤ 2 Mbps.

Drop Cp to 5 pF → f₃dB ≈ 530 MHz, plenty for 8–10 Mbps CAN-FD.

If you’re refreshing a legacy design using PESD2CAN,215, you can likely keep it for classic CAN, but migrate to low-Cp options for any new CAN-FD nodes.

For a more detailed comparison of signal-related protection behavior, check TEJTE’s RF cable and connector guide; the same high-frequency reflections and return-path concepts apply to automotive buses as well.

What changed in 2024–2025 for CAN/CAN-FD ESD parts?

If you haven’t looked at TVS diodes for CAN recently, the 2024–2025 generation is worth noting. Manufacturers are quietly pushing ESD protection toward lower capacitance, tighter clamping, and AEC-Q101 stability across wider operating ranges.

ROHM: next-gen CAN-FD TVS (3.5 pF class)

ROHM introduced a 3.5 pF series for CAN-FD applications, combining ultra-low capacitance with higher surge endurance (up to 5 A, 8/20 µs). Their lineup now specifically targets 5–10 Mbps systems — a direct evolution beyond PESD2CAN,215’s era. Early reports (GlobeNewswire, mid-2024) highlight their focus on EMC robustness for 24 V trucks and e-mobility gateways.

Bourns: CDSOT23-T24C-Q series

Bourns’ new AEC-Q101 qualified CDSOT23-T24C-Q line maintains a 24 V standoff with under 10 pF capacitance. The company’s automotive notes emphasize its use in CAN/CAN-FD/LIN mixed networks, where a single diode pair must cover multiple communication modes.

Texas Instruments: ESD2CANxx36-Q1 and ESD2CANFD24

TI went further, releasing dedicated CAN-FD ESD protection diodes rated up to 36 V standoff and only 2.5–2.8 pF. These parts are built for ECU and gateway designs transitioning to high-speed diagnostics and over-the-air updates.

Nexperia: evolving beyond PESD2CAN

While PESD2CAN,215 remains available, Nexperia has begun pivoting toward higher-voltage transient protection for 48 V and hybrid vehicle networks. That means future devices may shift from SOT-23 dual-line to leadless DFN or SOT-143B packages optimized for minimal inductance — a clear hint that the classic PESD2CAN footprint is nearing its sunset.

For ongoing updates about automotive connector and protection trends, see TEJTE’s semiconductor devices category; it’s where we track shifts in component lifecycles and compatibility for long-term sourcing.

How to replace PESD2CAN,215 safely without a board respin?

When a component goes NRND, the best engineers look for a drop-in substitute, not a redesign. Luckily, the PESD2CAN,215 follows a well-established SOT-23 dual-line footprint, shared by most CAN bus protection diodes in the market.

Still, not every look-alike behaves identically under surge. You must check five key specs before calling it “compatible”:

VRWM (Reverse Stand-Off Voltage) — should be 24 V ±2 V.
VBR (Breakdown Voltage) — ≥26 V.
VC(max) (Clamp Voltage @ Ipp) — ≤41 V.
Cp (Capacitance) — ≤25 pF for CAN, ≤10 pF preferred for CAN-FD.
AEC-Q101 & IEC 61000-4-2 compliance.

Below are three proven pin-compatible replacements that pass these filters:

Replacement	Package	VRWM	VBR (min)	VC (max @ Ipp)	Cp (pF)	AEC-Q	CAN-FD Ready?	Notes
ST ESDCAN2-2BLY	SOT-23	24 V	26 V	40 V @ 5 A	22 pF	✓	Limited	Reliable, same footprint
Bourns CDSOT23-T24CAN-Q	SOT-23	24 V	26.2 V	39 V @ 5 A	10 pF	✓	✓	Automotive CAN-FD certified
onsemi NUP2105L	SOT-23	27 V	28 V	41 V @ 5 A	17 pF	✓	Partial	Higher VBR, safe drop-in

All three will fit existing PESD2CAN,215 footprints without mechanical change.

If your PCB already integrates a choke before the transceiver, you can mix these variants even across ECUs — their leakage and capacitance differences are small enough that CAN differential symmetry remains stable.

Pro tip: When testing alternates, run a common-mode noise scan up to 500 MHz. If you see new spikes near 250–300 MHz, your Cp is slightly too high for CAN-FD edges.

You can find more examples of component drop-in strategy in TEJTE’s connector replacement guide, which follows the same discipline — verify specs, match mechanicals, and validate performance before mass adoption.

How to lay out pads, vias, and returns to cut clamp overshoot?

In transient protection, layout is the real limiter, not silicon. Even the best TVS diode can’t save you from a bad pad stack.

1. Ground return strategy

When the ESD current hits the CAN connector, it surges through the TVS diode to ground. The faster that current finds a low-impedance return, the lower your overshoot. That’s why layout engineers aim to minimize equivalent series inductance (ESL).

Practical layout tips:

Place two or more ground vias beside the diode pad; parallel vias halve ESL.
Keep the ground pour continuous — avoid narrow necks.
Route CANH/CANL with tight differential spacing right up to the diode.
If possible, add a small copper island tied to chassis ground near the connector shell to absorb ESD energy before it reaches the logic ground plane.

Measured overshoot tends to follow this empirical rule:

[ V_{overshoot} ≈ di/dt × L_{trace} ]

At 10 A/ns, even 1 nH adds 10 V. That’s why a 5 mm trace at 1 nH/mm can spike 50 V beyond your clamp. Keeping the trace under 3 mm and via-stitching aggressively can reduce the overshoot by 40% or more.

2. Connector spacing guidelines

Field data from automotive ECUs show a practical spacing threshold:

< 5 mm from connector pin to TVS pad — optimal (typical < 2 V overshoot).
5–10 mm — acceptable but risk of > 5 V transient spikes.
> 10 mm — fails ISO 7637 pulse 3a/3b repeatability in many cases.

3. Example cross-section

For reference on multi-layer via design and EMI suppression around connectors, see TEJTE’s IP67 connector blog; the same RF grounding principles apply directly to ESD protection diodes on CAN lines.

CAN/LIN TVS Selection Matrix + Replacement Checklist

Below is a consolidated selection matrix you can use when screening any automotive TVS diode for CAN or LIN applications.

TVS Diode Selection Matrix

Part (M)	Package	VRWM (V)	VBR (min) (V)	VC (max@Ipp) (V)	Ipp (8/20 μs)	Cp (pF @ 1 MHz)	AEC-Q	IEC 61000-4-2	CAN-FD OK?	Notes
Nexperia PESD2CAN,215	SOT-23	24	≥ 26.2	≤ 41	5 A	25	✓	±30 kV	–	Classic CAN only
ST ESDCAN2-4-2BLY	SOT-23	24	≥ 26	≤ 40	5 A	22	✓	±30 kV	Partial	Legacy ECU replacement
Bourns CDSOT23-T24CAN-Q	SOT-23	24	≥ 26.2	≤ 39	5 A	10	✓	±30 kV	✓	Ideal CAN-FD fit
onsemi NUP2105L	SOT-23	27	≥ 28	≤ 41	5 A	17	✓	±30 kV	Partial	Higher VBR variant

Rules for quick qualification

Clamp check:

If VC (max@Ipp) < transceiver ABS MAX and Cp ≤ speed threshold → safe.

Loss budget:

Overshoot ≈ di/dt × ESL (use 1 nH/mm as quick PCB estimate).

Replacement filtering:

Match package first, then verify VRWM ≈ 24 V ± 2 V, VBR ≥ 26 V, VC ≤ 41 V.

For CAN-FD, prioritize Cp ≤ 10 pF.

Design tip

Whenever you integrate ESD diodes in mixed CAN + LIN topologies, check common-mode balance. Even a 3 pF mismatch between lines can distort your bit edge. That’s why modern designs use matched dual diodes with symmetrical routing — exactly the configuration found in PESD2CAN,215 and its drop-in successors.

What mistakes kill ESD compliance most often?

Even seasoned engineers repeat the same few sins when implementing automotive ESD protection — usually because layout, not the diode, betrays them.

Placing the TVS far from the connector.

Every millimeter adds inductance; every nanohenry adds volts. Keep it right next to the CAN pins.

Using a power-line TVS on signal lines.

High-capacitance 600 W parts clamp well, but they destroy signal integrity above 1 Mbps. Always use signal-line TVS diodes (SOT-23 or DFN packages) rated for low Cp.

Ignoring via current sharing.

A single via can saturate; use at least two parallel vias for each diode pad.

Overlooking adapter or harness stacks.

Each added connector or extension adds reflection points. Test with the final cable assembly attached.

Skipping post-ESD re-test.

Some failures only appear after multiple 30 kV hits — watch for slow leakage drift or shifted threshold voltages.

Rule of thumb: ESD protection doesn’t just pass once — it passes 1000 times. If you only survive the first pulse, you haven’t protected, you’ve delayed failure.

For a deeper exploration of connector grounding and overshoot reduction, you can revisit TEJTE’s MIMO antenna article, which demonstrates the same high-frequency current path control that keeps ESD safe in differential systems.

Frequently Asked Questions (FAQ)

1. Is PESD2CAN,215 still safe to design in?

Yes — but with a warning label. Nexperia’s PESD2CAN,215 remains a fully qualified automotive TVS diode under AEC-Q101, yet its NRND status means it’s no longer recommended for new platforms. If you already have a validated PCB layout, keep using it. For new designs, switch to a drop-in option like Bourns CDSOT23-T24CAN-Q or ST ESDCAN24-2BLY to secure long-term sourcing and consistent ESD margins.

2. Will a 24 V TVS diode work for both 12 V and 24 V CAN systems?

Absolutely. The CAN bus lines (CANH and CANL) are differential signals that swing within a few volts of ground, even in 24 V vehicles. A 24 V stand-off TVS diode protects both systems equally. Just remember: this covers signal-line surges, not load-dump events on the main power rail — that’s where you’ll need a separate power-line transient suppressor.

3. What capacitance is safe for CAN-FD 5–10 Mbps operation?

As bit rates climb, the line capacitance (Cp) of your ESD protection diode becomes a limiting factor. For classical CAN (1 Mbps), 20–25 pF is fine. For CAN-FD, aim for ≤ 10 pF to maintain clean edges and eye-diagram margins. Modern parts like TI ESD2CANFD24-Q1 or ROHM’s 3.5 pF series offer excellent signal integrity at 8–10 Mbps.

4. Can I rely on the transceiver’s internal ESD protection instead?

Not recommended. Built-in ESD cells inside the transceiver can absorb small pulses, but they can’t safely dissipate the 8 kV contact / 30 kV air energy defined by IEC 61000-4-2. An external TVS diode provides a low-impedance shunt path at the connector, protecting the silicon before it even feels the surge. Think of it as a first-line shield, not redundancy.

5. How close should the TVS diode sit to the CAN connector?

The closer, the better — ideally within 3–5 mm of the CANH and CANL pins. Every extra millimeter adds parasitic inductance, which translates into overshoot (ΔV ≈ L × di/dt). Short traces and dual vias near the pad dramatically cut clamp voltage. Layout quality often matters more than which ESD protection diode you choose.

6. What are reliable drop-in alternatives to PESD2CAN,215?

Three proven choices stand out:

ST ESDCAN24-2BLY – same 24 V spec, compatible footprint.
Bourns CDSOT23-T24CAN-Q – low Cp (~10 pF), CAN-FD ready.
onsemi NUP2105L – slightly higher VBR (~28 V), robust for harsh nodes.

All are AEC-Q101 qualified and tested under ±30 kV contact discharge.

7. What’s new in 2024–2025 for automotive CAN ESD protection?

Manufacturers are chasing lower capacitance and higher surge endurance. ROHM released ~3.5 pF CAN-FD diodes, Bourns added the CDSOT23-T24C-Q with improved thermal cycling, and TI expanded to 36 V standoff for hybrid networks. Nexperia’s roadmap hints at leadless DFN replacements for 48 V domains — signaling a new generation of automotive TVS diodes beyond the PESD2CAN footprint.

Conclusion

The PESD2CAN,215 may be entering retirement, but its legacy endures: a clean, reliable, automotive-qualified TVS diode for CAN bus ESD protection that defined the 24 V, 25 pF standard for over a decade.

For classic CAN, it remains perfectly valid — provided you can still source it. For new CAN-FD or mixed 48 V networks, move toward lower-capacitance successors from Bourns, TI, or STMicroelectronics.

In every case, the rules don’t change:

Choose by spec alignment, not by name.
Place it as close to the connector as physics allows.
Verify clamp below ±58 V, and keep Cp under 10 pF for fast buses.

Done right, your CAN transceivers will pass IEC 61000-4-2 testing the first time — and stay quiet for years in the field.

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