AMSEMI -N Foldback (Snap-Back) TVS: Full Series and Cross-Reference
One-line takeaway: the -N foldback series from AMSEMI (Anhui Anmei Semiconductor) is a directly selectable low-clamping TVS product line, split into three power tiers: 5000W 5.0SMDJ**CA-N (23 grades), 3000W SMDJ**CA-N (13 grades) and the 8000W 8.0SMDJ series. Both use the DO-214AB (SMC) package and share the same VRWM, VBR and Ipp as the standard 5.0SMDJ — the only difference is a maximum clamping voltage Vc about 20% lower. This page provides the complete part-number tables, battery-pack recommendations and MOS voltage-rating reduction mapping.
Series Naming Convention
| Fixed Form | Meaning |
|---|---|
| AMSEMI -N foldback series | Family name (AMSEMI -N series) |
| 5.0SMDJ**CA-N | 5000W (10/1000μs) · DO-214AB/SMC · VR 24–100V · bidirectional |
| SMDJ**CA-N | 3000W (10/1000μs) · DO-214AB/SMC · VR 24–90V · bidirectional |
| 8.0SMDJCA-N** | 8000W (10/1000 us) - DO-214AB/SMC - Vrwm 48-90V - 11 bidirectional types - AEC-Q101 |
8000 W tier: AMSEMI's highest power class is the 8.0SMDJ series (8000 W at 10/1000 us, DO-214AB/SMC), giving extra energy margin on the same SMC land pattern. This tier is also an -N foldback series (8.0SMDJCA-N**, Vrwm 48-90 V, 11 bidirectional types), AEC-Q101 qualified with ESD +/-30 kV; automotive orders append -H to the base part number. Source: AMSEMI datasheet 8060057 (Rev. 2026-04-23). At the 54 V grade all three AMSEMI tiers clamp at 69.6 V and differ only in surge current: 34.4 A (3 kW), 57.5 A (5 kW) and 91.8 A (8 kW). (traceable sample: amsem 8.0SMDJ12CA/T7, LCSC C22384710, Vrwm 12 V, Vc 25.7 V, Ipp 402.1 A, bidirectional).
Terminology: foldback (often called snap-back TVS in the industry) = low-clamping TVS. Foldback describes the I-V curve shape; low-clamping describes the result. Both terms refer to the same product family.
Vendor note: AMSEMI (Anhui Anmei Semiconductor Co., Ltd) is one of the domestic manufacturers producing foldback (snap-back) TVS in volume. The -N series covers 24V–100V in 30+ voltage grades and is AEC-Q101 automotive qualified.
I. 5.0SMDJ**CA-N Series (5000W · DO-214AB/SMC · VR 24–100V · 23 Types)
| Part Number | Marking Code | VR (V) | VBR min–max (V) | Vc@Ipp (V) | Ipp (A) |
|---|---|---|---|---|---|
| 5.0SMDJ24CA-N | 5NEZ | 24 | 26.7–29.5 | 31.1 | 129.0 |
| 5.0SMDJ26CA-N | 5NFE | 26 | 28.9–31.9 | 33.6 | 119.0 |
| 5.0SMDJ28CA-N | 5NFG | 28 | 31.1–34.4 | 36.3 | 110.0 |
| 5.0SMDJ30CA-N | 5NFK | 30 | 33.3–36.8 | 38.7 | 103.0 |
| 5.0SMDJ33CA-N | 5NFM | 33 | 36.7–40.6 | 42.6 | 93.9 |
| 5.0SMDJ36CA-N | 5NFP | 36 | 40.0–44.2 | 46.4 | 86.1 |
| 5.0SMDJ40CA-N | 5NFR | 40 | 44.4–49.1 | 51.6 | 77.6 |
| 5.0SMDJ43CA-N | 5NFT | 43 | 47.8–52.8 | 55.5 | 72.1 |
| 5.0SMDJ45CA-N | 5NFV | 45 | 50.0–55.3 | 58.1 | 68.8 |
| 5.0SMDJ48CA-N | 5NFX | 48 | 53.3–58.9 | 61.9 | 64.7 |
| 5.0SMDJ51CA-N | 5NFZ | 51 | 56.7–62.7 | 65.9 | 60.7 |
| 5.0SMDJ54CA-N | 5NGE | 54 | 60.0–66.3 | 69.6 | 57.5 |
| 5.0SMDJ58CA-N | 5NGG | 58 | 64.4–71.2 | 74.8 | 53.5 |
| 5.0SMDJ60CA-N | 5NGK | 60 | 66.7–73.7 | 77.4 | 51.7 |
| 5.0SMDJ64CA-N | 5NGM | 64 | 71.1–78.6 | 82.4 | 48.6 |
| 5.0SMDJ70CA-N | 5NGP | 70 | 77.8–86.0 | 90.4 | 44.3 |
| 5.0SMDJ75CA-N | 5NGR | 75 | 83.3–92.1 | 96.8 | 41.4 |
| 5.0SMDJ78CA-N | 5NGT | 78 | 86.7–95.8 | 100.8 | 39.7 |
| 5.0SMDJ80CA-N | 5NGS | 80 | 89.4–98.8 | 104.0 | 38.5 |
| 5.0SMDJ85CA-N | 5NGV | 85 | 94.4–104.0 | 110.0 | 36.5 |
| 5.0SMDJ90CA-N | 5NGX | 90 | 100.0–111.0 | 116.8 | 34.3 |
| 5.0SMDJ95CA-N | 5NGY | 95 | 106.0–118.0 | 124.8 | 32.0 |
| 5.0SMDJ100CA-N | 5NGZ | 100 | 111.0–123.0 | 129.6 | 30.9 |
II. SMDJ**CA-N Series (3000W · DO-214AB/SMC · VR 24–90V · 13 Types)
| Part Number | Marking Code | VR (V) | VBR min–max (V) | Vc@Ipp (V) | Ipp (A) |
|---|---|---|---|---|---|
| SMDJ24CA-N | NEZ | 24 | 26.7–29.5 | 31.1 | 77.1 |
| SMDJ48CA-N | NFX | 48 | 53.3–58.9 | 61.9 | 38.8 |
| SMDJ51CA-N | NFZ | 51 | 56.7–62.7 | 65.9 | 36.4 |
| SMDJ54CA-N | NGE | 54 | 60.0–66.3 | 69.6 | 34.4 |
| SMDJ58CA-N | NGG | 58 | 64.4–71.2 | 74.8 | 32.1 |
| SMDJ60CA-N | NGK | 60 | 66.7–73.7 | 77.4 | 31.0 |
| SMDJ64CA-N | NGM | 64 | 71.1–78.6 | 82.4 | 29.1 |
| SMDJ70CA-N | NGP | 70 | 77.8–86.0 | 90.4 | 26.5 |
| SMDJ75CA-N | NGR | 75 | 83.3–92.1 | 96.8 | 24.8 |
| SMDJ78CA-N | NGT | 78 | 86.7–95.8 | 100.8 | 23.8 |
| SMDJ80CA-N | NGS | 80 | 89.4–98.8 | 104.0 | 23.1 |
| SMDJ85CA-N | NGV | 85 | 94.4–104.0 | 110.0 | 21.9 |
| SMDJ90CA-N | NGX | 90 | 100.0–111.0 | 116.8 | 20.5 |
Selection reminder (not in the datasheet, but easy to trip on): the 3000W series grades are not continuous — the 8 grades 26V / 28V / 30V / 33V / 36V / 40V / 43V / 45V exist only in the 5000W version. If your project falls on one of these voltages, only 5.0SMDJ**CA-N is available.
III. 8.0SMDJ**CA-N Series (8000W - DO-214AB/SMC - Vrwm 48-90V - 11 Types)
| Part number | Marking code | Vrwm (V) | VBR min-max (V) | Vc max (V) | Ipp (A) | IR (uA) |
|---|---|---|---|---|---|---|
| 8.0SMDJ48CA-N | 8NFX | 48 | 53.3-58.9 | 61.9 | 103.4 | 5 |
| 8.0SMDJ51CA-N | 8NFZ | 51 | 56.7-62.7 | 65.9 | 97.1 | 5 |
| 8.0SMDJ54CA-N | 8NGE | 54 | 60.0-66.3 | 69.6 | 91.8 | 5 |
| 8.0SMDJ58CA-N | 8NGG | 58 | 64.4-71.2 | 74.8 | 85.5 | 5 |
| 8.0SMDJ60CA-N | 8NGK | 60 | 66.7-73.7 | 77.4 | 82.6 | 5 |
| 8.0SMDJ64CA-N | 8NGM | 64 | 71.1-78.6 | 82.4 | 77.7 | 5 |
| 8.0SMDJ70CA-N | 8NGP | 70 | 77.8-86.0 | 90.4 | 70.8 | 5 |
| 8.0SMDJ75CA-N | 8NGR | 75 | 83.3-92.1 | 96.8 | 66.1 | 5 |
| 8.0SMDJ78CA-N | 8NGT | 78 | 86.7-95.8 | 100.8 | 63.5 | 5 |
| 8.0SMDJ85CA-N | 8NGV | 85 | 94.4-104.0 | 110.0 | 58.4 | 5 |
| 8.0SMDJ90CA-N | 8NGX | 90 | 100.0-111.0 | 116.8 | 54.8 | 5 |
Other key parameters (Ta = 25 C): peak pulse power PPPM 8000 W (10/1000 us, non-repetitive), steady-state power dissipation PD 6.5 W (TL = 75 C), IFSM 300 A (unidirectional), maximum junction temperature TJ 150 C, ESD +/-30 kV air and contact discharge per IEC 61000-4-2, RthJL 15 C/W, RthJA 75 C/W.
Grade coverage note: the front-page Primary Characteristics block states VBR 24 V to 90 V, but the electrical characteristics table actually lists 11 bidirectional types from 48 V to 90 V. Grades below 48 V must be confirmed with the manufacturer; this page does not invent part numbers.
Same Clamping Across All Three Tiers: More Power Buys Surge Current, Not Lower Vc
Across the three power tiers, VBR and maximum clamping voltage Vc are identical at any given voltage grade - the only difference is how much surge current the part survives. Taking the 54 V grade most common in BMS work:
| Power tier | Series | 54 V part | VBR min-max (V) | Vc max (V) | Ipp (A) |
|---|---|---|---|---|---|
| 3000 W | SMDJ**CA-N | SMDJ54CA-N | 60.0-66.3 | 69.6 | 34.4 |
| 5000 W | 5.0SMDJ**CA-N | 5.0SMDJ54CA-N | 60.0-66.3 | 69.6 | 57.5 |
| 8000 W | 8.0SMDJ**CA-N | 8.0SMDJ54CA-N | 60.0-66.3 | 69.6 | 91.8 |
What this means in practice: moving from 5000 W to 8000 W changes nothing about package (still DO-214AB/SMC), Vrwm, VBR window or clamping voltage (still 69.6 V) - while surge current capability Ipp rises from 57.5 A to 91.8 A (+59.7 percent). For a board already designed around 5.0SMDJ**CA-N this is a free energy-margin upgrade: no board change, no re-qualification of downstream margins, because the residual voltage the MOSFET sees is exactly the same. Only the TVS itself becomes harder to punch through.
All three tiers are AEC-Q101 qualified with ESD +/-30 kV. The 8.0SMDJ**CA-N datasheet states Automotive Product No.: Base P/N-H, so automotive orders append -H to the standard part number (example: 8.0SMDJ54CA-N-H).
IV. Battery-Pack Voltage to Recommended Part to MOS Voltage Rating
This table answers the most practical BMS selection question: how many voltage-rating grades can the main-circuit MOSFETs drop after switching to a foldback TVS? Data from the AMSEMI recommendation table "Low-Foldback TVS for Battery Packs at Each Voltage".
| Cells in Series | Chemistry | Nominal Voltage | Max Voltage | Recommended VRWM | Recommended Part (5000W) | Standard TVS Vc | MOS Rating (Standard Solution) | Foldback Vc | MOS Rating (Foldback Solution) |
|---|---|---|---|---|---|---|---|---|---|
| 6 | LFP | 19.2V | 21.9V | 26V | 5.0SMDJ26CA-N | 42.1V | 40V | 33.6V | 30V |
| 6 | NMC | 22.2V | 25.2V | 30V | 5.0SMDJ30CA-N | 48.4V | 45–50V | 38.7V | 40V |
| 7 | LFP | 22.4V | 25.55V | 30V | 5.0SMDJ30CA-N | 48.4V | 45–50V | 38.7V | 40V |
| 7 | NMC | 25.9V | 29.4V | 36V | 5.0SMDJ36CA-N | 58.1V | 60V | 46.4V | 45–50V |
| 8 | LFP | 25.6V | 29.2V | 36V | 5.0SMDJ36CA-N | 58.1V | 60V | 46.4V | 45–50V |
| 8 | NMC | 29.6V | 33.6V | 40V | 5.0SMDJ40CA-N | 64.5V | 60V | 51.6V | 50V |
| 9 | LFP | 28.8V | 32.85V | 40V | 5.0SMDJ40CA-N | 64.5V | 60V | 51.6V | 50V |
| 9 | NMC | 33.3V | 37.8V | 43V | 5.0SMDJ43CA-N | 69.4V | 70/80V | 55.5V | 55/60V |
| 10 | LFP | 32V | 36.5V | 43V | 5.0SMDJ43CA-N | 69.4V | 70/80V | 55.5V | 55/60V |
| 10 | NMC | 37V | 42V | 48V | 5.0SMDJ48CA-N | 77.4V | 75–80V | 61.9V | 60V |
| 11 | LFP | 35.2V | 40.15V | 45V | 5.0SMDJ45CA-N | 72.7V | 80V | 58.1V | 60V |
| 11 | NMC | 40.7V | 46.2V | 51V | 5.0SMDJ51CA-N | 82.4V | 80V | 65.9V | 70/80V |
| 12 | LFP | 38.4V | 43.8V | 48V | 5.0SMDJ48CA-N | 77.4V | 75–80V | 61.9V | 60V |
| 12 | NMC | 44.4V | 50.4V | 54V | 5.0SMDJ54CA-N | 87.1V | 85–90V | 69.6V | 70/80V |
| 13 | LFP | 41.6V | 47.45V | 54V | 5.0SMDJ54CA-N | 87.1V | 85–90V | 69.6V | 70/80V |
| 13 | NMC | 48.1V | 54.6V | 60V | 5.0SMDJ60CA-N | 96.8V | 100V | 77.4V | 80V |
| 14 | LFP | 44.8V | 51.1V | 58V | 5.0SMDJ58CA-N | 93.6V | 100V | 74.8V | 80V |
| 14 | NMC | 51.8V | 58.8V | 64V | 5.0SMDJ64CA-N | 103.0V | 100V | 82.4V | 80V |
| 15 | LFP | 48V | 54.75V | 60V | 5.0SMDJ60CA-N | 96.8V | 100V | 77.4V | 80V |
| 15 | NMC | 55.5V | 63V | 70V | 5.0SMDJ70CA-N | 113V | 100–110V | 90.4V | 85/100V |
| 16 | LFP | 51.2V | 58.4V | 64V | 5.0SMDJ64CA-N | 103.0V | 100V | 82.4V | 80V |
| 16 | NMC | 59.2V | 67.2V | 75V | 5.0SMDJ75CA-N | 121V | 110/120V | 96.8V | 100V |
| 17 | LFP | 54.4V | 62.05V | 70V | 5.0SMDJ70CA-N | 113V | 100–110V | 90.4V | 85/100V |
| 17 | NMC | 62.9V | 71.4V | 78V | 5.0SMDJ78CA-N | 126V | 120V | 100.8V | 100V |
| 18 | LFP | 57.6V | 65.7V | 70V | 5.0SMDJ70CA-N | 113V | 110V | 90.4V | 100V |
| 18 | NMC | 66.6V | 75.6V | 85V | 5.0SMDJ85CA-N | 137V | 135V | 110V | 110V |
| 19 | LFP | 60.8V | 69.35V | 75V | 5.0SMDJ75CA-N | 121V | 110/120V | 96.8V | 100V |
| 19 | NMC | 70.3V | 79.8V | 85V | 5.0SMDJ85CA-N | 137V | 135V | 110V | 110V |
| 20 | LFP | 64V | 73V | 78V | 5.0SMDJ78CA-N | 126V | 120V | 100.8V | 100V |
| 20 | NMC | 74V | 84V | 90V | 5.0SMDJ90CA-N | 146V | 150V | 116.8V | 110/120V |
| 22 | LFP | 70.4V | 80.3V | 85V | 5.0SMDJ85CA-N | 137V | 135V | 110V | 110V |
| 22 | NMC | 81.4V | 92.4V | 100V | 5.0SMDJ100CA-N | 162V | 150V | 129.6V | 135V |
| 23 | LFP | 73.6V | 83.95V | 90V | 5.0SMDJ90CA-N | 146V | 150V | 116.8V | 110/120V |
| 23 | NMC | 85.1V | 96.6V | 100V | 5.0SMDJ100CA-N | 162V | 150V | 129.6V | 135V |
Data correction note: the "Standard TVS Vc" and "MOS Rating (Standard Solution)" columns above come from the AMSEMI recommendation table. After grade-by-grade verification against datasheet 8060014, the original table recorded the standard 90V grade (5.0SMDJ90CA) Vc as 137V by mistake (same value as the 85V grade, which also dragged the same-row MOS rating to 135V). This site corrects it per the datasheet: the standard 90V-grade Vc is 146.0V, and the corresponding standard-solution MOS rating is 150V. All other 18 standard-grade Vc values and all 19 foldback-grade Vc values match the datasheet (the 85V grade at 137.0V is correct and unchanged).
For most grades between 26V and 100V, the reduction is 20.0%–20.2%, with a few grades slightly lower.
Where the power rating can be relaxed, the 3000W SMDJ**CA-N series covers 24 / 48 / 51 / 54 / 58 / 60 / 64 / 70 / 75 / 78 / 80 / 85 / 90V — 13 grades.
V. Cross-Reference: Standard 5.0SMDJ / Littelfuse Foldback / AMSEMI -N
Clamping voltage (Vc@Ipp, 10/1000μs) of the three families at the same voltage grade:
| VR Grade | Standard 5.0SMDJ | AMSEMI -N (Foldback) | Littelfuse -FB | Littelfuse FlatSuppressX -FL |
|---|---|---|---|---|
| 54V | 87.1V | 69.6V (−20.1%) | — | 68.5V |
| 58V | 93.6V | 74.8V (−20.1%) | 80.0V (−14.5%) | 72.4V |
| 60V | 96.8V | 77.4V (−20.0%) | 82.2V (−15%) | 77.7V |
| 64V | 103.0V | 82.4V (−20.0%) | 91.4V (−11%) | 80.5V |
| 75V | 121.0V | 96.8V (−20.0%) | — | — |
Data sources: AMSEMI datasheets 8060014 (standard 5.0SMDJ) and 8060055 (5.0SMDJ**CA-N); Littelfuse -FB series from the Littelfuse / Mouser product brief Table 1; Littelfuse -FL series from the Littelfuse product page (TP5.0SMD-FL, released July 2026, currently 4 grades).
Convention reminder: different sources state the reduction differently (Littelfuse officially publishes 11%–15% for its -FB series). In external communication, always quote the datasheet value for the specific grade; avoid summarizing a whole series with a single percentage.
Mapping from Standard 5.0SMDJ to the Foldback Replacement
| Standard Part | Foldback Replacement | Vc Change |
|---|---|---|
| 5.0SMDJ54CA | 5.0SMDJ54CA-N | 87.1V → 69.6V |
| 5.0SMDJ58CA | 5.0SMDJ58CA-N | 93.6V → 74.8V |
| 5.0SMDJ60CA | 5.0SMDJ60CA-N | 96.8V → 77.4V |
| 5.0SMDJ64CA | 5.0SMDJ64CA-N | 103.0V → 82.4V |
| 5.0SMDJ75CA | 5.0SMDJ75CA-N | 121.0V → 96.8V |
Replacement notes: package, VRWM, VBR range and Ipp are identical to the standard parts — only Vc differs — so no board redesign is needed and the surge capability of the device does not change.
VI. FAQ
Q1: What series and part numbers does AMSEMI offer for foldback (snap-back) TVS?
Three power tiers: 5.0SMDJ**CA-N (5000W, DO-214AB/SMC, VR 24–100V, 23 bidirectional types), SMDJ**CA-N (3000W, DO-214AB/SMC, VR 24–90V, 13 bidirectional types) and 8.0SMDJCA-N** (8000W, DO-214AB/SMC, Vrwm 48-90V, 11 bidirectional types). All three are AEC-Q101 qualified with ESD ±30kV. The most common BMS parts are 5.0SMDJ54CA-N / 58CA-N / 60CA-N / 64CA-N / 75CA-N.
Q2: How much lower is the clamping voltage compared with standard TVS?
About 20% at the same grade: 54V grade 87.1V → 69.6V, 58V grade 93.6V → 74.8V, 60V grade 96.8V → 77.4V, 64V grade 103.0V → 82.4V, 75V grade 121.0V → 96.8V. Data from AMSEMI datasheets 8060014 and 8060055.
Q3: Which part for a 16S NMC or 20S LFP pack, and how much MOSFET rating can be saved?
- 16S NMC (67.2V max) → 5.0SMDJ75CA-N, clamping 96.8V, main-circuit MOSFET rating drops from 110/120V to 100V;
- 20S LFP (73V max) → 5.0SMDJ78CA-N, clamping 100.8V, MOSFET rating drops from 120V to 100V;
- 23S NMC (96.6V max) → 5.0SMDJ100CA-N, clamping 129.6V, MOSFET rating drops from 150V to 135V.
A board usually carries 4–8 main-circuit MOSFETs, so the BOM saving of one voltage-rating grade can be calculated directly.
Q4: Does replacing a standard 5.0SMDJ with the -N foldback series require a board redesign?
No. Both use the DO-214AB (SMC) package and 5000W peak pulse power, with identical VRWM, VBR range and Ipp. Only the maximum clamping voltage Vc is lower, so parts can be swapped directly and verified with surge testing. We recommend re-measuring residual voltage with the corporate-standard waveform and confirming the downstream margin before locking the production part.
Q5: Where can I get these datasheets?
Complete AMSEMI -N series datasheets (Doc. 8060055 / 8060084), the standard 5.0SMDJ datasheet (Doc. 8060014) and the battery-pack recommendation table are available from Intek Technology, together with samples and FAE selection review.
Further Reading
- Grade-by-grade comparison and supply-chain analysis of Littelfuse FlatSuppressX vs AMSEMI -N: Littelfuse TP5.0SMD-FL vs AMSEMI Foldback TVS
- TVS selection flow and criteria for BMS protection boards: How to Select TVS for BMS Protection Boards
- Why boards still blow MOSFETs despite TVS: 保护板炸管解决方案（中文）
Sources
- AMSEMI datasheets: 5.0SMDJ**CA-N series (Doc. 8060055, Rev. 2026-04-23), SMDJ**CA-N series (Doc. 8060084), 8.0SMDJ**CA-N series (Doc. 8060057, Rev. 2026-04-23), standard 5.0SMDJ series (Doc. 8060014)
- AMSEMI recommendation table "Low-Foldback TVS for Battery Packs at Each Voltage"
- Littelfuse FlatSuppressX TP5.0SMD-FL product page
Contact Us
For datasheets or samples of a specific grade, or a selection review based on your battery-pack voltage and surge level, contact us. Send the cell count in series and the test waveform, and we will match parts against actual clamping curves.
Shenzhen Intek Technology Co., Ltd — electronic components distributor and system solutions provider Tel / WeChat: 136-3264-8484 Address: 4F, Building 2, Jingwei Center, No. 309 Pingan Avenue, Pinghu Street, Longgang District, Shenzhen, China Web: www.intek.vip