My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SM8S51CAHM3/I
- Part No.:
- SM8S51CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM8S51CAHM3/I.pdf
- Description:
- 6600 W BI-DIRECTIONAL TVS IS DO-
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM8S51CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection. It features a 51 V stand-off voltage (VWM), 59.7 V nominal breakdown voltage (VBR), 82.4 V maximum clamping voltage at 80.1 A peak pulse current, and 6600 W peak pulse power rating with 10/1000 μs waveform.
For engineers reviewing the SM8S51CAHM3/I datasheet, SM8S51CAHM3/I pinout, SM8S51CAHM3/I application, or SM8S51CAHM3/I equivalent, this device is selected for high-reliability 12 V/24 V automotive power rail protection where AEC-Q101 qualification, TJ = 175 °C operation, ISO 7637-2 compliance, and DO-218AC package thermal performance are critical design requirements.
Technical Context
This TVS diode operates in bidirectional avalanche mode to clamp transient overvoltages induced by inductive switching and load dump events. Its DO-218AC package integrates a metal heatsink terminal for low RθJM (0.35 °C/W) and supports high surge capability without external heatsinking.
The device is characterized for stable performance across -55 °C to +175 °C junction temperature, with ≤10 μA reverse leakage at VWM and full compliance to ISO 16750-2 test conditions when applied per manufacturer-specified mounting and layout guidelines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51.0 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating margin for 42 V automotive systems. |
| VBR (nom) | 59.7 V - Voltage at which device enters avalanche conduction at 5 mA test current; ensures reliable triggering above normal system transients. |
| VC @ IPPM | 82.4 V - Clamped voltage at 80.1 A peak pulse current; limits downstream IC stress during ISO 7637-2 Pulse 5a load dump events. |
| PPPM (10/1000 μs) | 6600 W - Peak pulse power handling capacity; enables single-device protection against severe automotive surges without derating. |
| TJ max | +175 °C - Maximum junction temperature rating; supports under-hood placement in modern engine control units and ADAS modules. |
| Package | DO-218AC - Surface-mount package with integrated metal heatsink terminal; provides 0.35 °C/W junction-to-mount thermal resistance for direct PCB thermal coupling. |
| AEC-Q101 | Qualified - Certified for automotive-grade reliability per stress test requirements including HTGB, HTRB, and TCT; required for ECU and body control module designs. |
Pinout & Package
DO-218AC package with two terminals: Lead 1 (anode/cathode-indifferent) and Lead 2 / Metal Heatsink (common reference plane). The bidirectional structure eliminates polarity marking; both terminals function identically in surge conduction path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Anode/Cathode (bidirectional) | Primary surge current entry/exit point; symmetric conduction path enables placement without orientation constraints. |
| Lead 2 / Metal Heatsink | Thermal & Electrical Reference | Low-inductance, high-current return path and primary thermal interface to PCB copper pour; must be soldered to ≥100 mm² 2 oz. copper area for rated PPPM. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating rails without polarity concerns; eliminates need for dual-diode configurations. |
| 175 °C junction rating | Supports direct mounting near heat-generating components (e.g., power MOSFETs, DC/DC converters) in compact automotive ECUs without thermal derating. |
| ISO 7637-2 compliance | Validated for Pulse 5a (load dump) up to 42 V systems; meets OEM-level surge immunity requirements without additional filtering stages. |
| MSL Level 1 | Allows standard SMT reflow without moisture sensitivity precautions; compatible with high-volume automotive manufacturing processes. |
| Halogen-free & RoHS | Meets global environmental regulations and automotive material compliance standards (Vishay Doc. 99912); suitable for Tier 1 supply chain traceability. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) CAN Bus Interface |
|---|---|
Use Scenario: Protects 12 V main power input of gasoline/diesel engine ECUs from alternator load dump transients exceeding 60 V. IC Role / Device Role / Timing Role: Primary front-end TVS clamp; absorbs >95 % of 6600 W surge energy within 10 ms window. Use Value: Prevents latch-up or permanent damage to MCU, power management ICs, and analog sensors during cold-cranking and battery disconnect events. | Use Scenario: Shields isolated CAN transceivers and common-mode chokes from coupled transients entering via shared vehicle ground or power lines. IC Role / Device Role / Timing Role: Secondary protection stage placed upstream of common-mode filter; clamps differential and common-mode surges simultaneously. Use Value: Maintains CAN FD communication integrity during ISO 16750-2 transient tests without signal distortion or bus lockup. |
| ADAS Camera Power Rail | Electric Power Steering (EPS) Motor Driver |
Use Scenario: Secures 5 V/3.3 V camera module power supplies derived from buck converters fed by protected 12 V input. IC Role / Device Role / Timing Role: Point-of-load TVS on secondary-side regulator input; responds within <1 ns to fast-rising ESD and switching noise. Use Value: Eliminates image artifacts and frame drops caused by sub-100 ns transients that bypass bulk capacitance on compact camera PCBs. | Use Scenario: Guards gate driver ICs and high-side/low-side MOSFETs in EPS motor inverters against inductive kickback from 3-phase BLDC commutation. IC Role / Device Role / Timing Role: Snubber-connected TVS across DC bus; clamps voltage spikes up to 82.4 V during rapid PWM turn-off transitions. Use Value: Extends MOSFET lifetime by limiting VDS stress below 85 % of rated breakdown, reducing cumulative degradation in safety-critical steering systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51CA | Lower PPPM (400 W vs. 6600 W); DO-214AC package; no metal heatsink terminal; RθJM = 55 °C/W. | Restricted to low-energy transients (e.g., ESD, I/O line protection); unsuitable for load dump. | Select SMAJ51CA only for non-automotive, low-power signal-line protection where space is constrained and surge energy is <500 W. |
| TPSMD51CA | Same DO-218AC package and 6600 W rating; identical VWM/VBR/VC; but not AEC-Q101 qualified; higher ID at 175 °C (50 μA vs. 10 μA). | Limited to industrial or commercial automotive after-market use; not approved for OEM ECU integration. | Choose TPSMD51CA only if AEC-Q101 certification is not contractually required and long-term high-temperature leakage is acceptable. |
Compared with SMAJ51CA and TPSMD51CA, SM8S51CAHM3/I uniquely combines AEC-Q101 qualification, 175 °C operation, and 6600 W surge capability in the DO-218AC package-making it the only option qualified for front-end protection in production automotive ECUs subject to ISO 7637-2 Pulse 5a.
Availability
SM8S51CAHM3/I is available at Aetrix Electronics and suitable for automotive electronic control units, body control modules, ADAS camera systems, and electric power steering designs requiring stable component supply with full AEC-Q101 traceability and long-lifecycle support.
Supply support for SM8S51CAHM3/I includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in high-reliability diodes, MOSFETs, and optoelectronics for automotive, industrial, and computing markets.
The SM8SxxCA family is engineered specifically for automotive load dump and ISO 7637-2 transient suppression, emphasizing thermal robustness, AEC-Q101 compliance, and DO-218AC package integration for under-hood power rail protection.
FAQ
What is the maximum clamping voltage of the SM8S51CAHM3/I at its rated peak pulse current?
The SM8S51CAHM3/I has a maximum clamping voltage (VC) of 82.4 V at its rated peak pulse current (IPPM) of 80.1 A with a 10/1000 μs waveform. This value is measured per Figure 4 in the Vishay datasheet (Doc. 98229) and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The SM8S51CAHM3/I maintains this clamping performance across its full operating temperature range.
Is the SM8S51CAHM3/I suitable for 24 V commercial vehicle applications?
Yes, the SM8S51CAHM3/I is suitable for 24 V commercial vehicle applications. Its 51 V stand-off voltage (VWM) provides adequate margin above nominal 24 V system levels, and its 82.4 V clamping voltage remains within safe limits for 36 V-rated downstream components. The device is explicitly validated for ISO 7637-2 Pulse 5a testing up to 42 V systems, covering both 12 V passenger cars and 24 V heavy-duty vehicles. SM8S51CAHM3/I's AEC-Q101 qualification further confirms its suitability for demanding commercial vehicle environments.
Does the SM8S51CAHM3/I require a specific PCB layout to achieve its rated 6600 W pulse power?
Yes, the SM8S51CAHM3/I requires a defined PCB layout to achieve its rated 6600 W peak pulse power. Per Vishay's DO-218AC mounting recommendations, the metal heatsink terminal (Lead 2) must be soldered to a minimum 100 mm² area of 2 oz. copper on the PCB. This layout ensures the specified RθJM of 0.35 °C/W and prevents thermal runaway during surge events. Failure to implement this copper pour will reduce effective PPPM and may cause premature failure. The SM8S51CAHM3/I datasheet provides exact pad dimensions in inches and millimeters on page 5.
How does the SM8S51CAHM3/I differ from the SM8S51A variant?
The SM8S51CAHM3/I is bidirectional (indicated by "CA"), while the SM8S51A is unidirectional ("A"). The "CA" suffix specifies symmetrical clamping behavior for AC or floating circuits, whereas "A" provides clamping only in reverse bias. Both share identical VWM (51 V), VBR (59.7 V), VC (82.4 V), and PPPM (6600 W), but the SM8S51CAHM3/I eliminates polarity-dependent placement and supports differential surge suppression. The "HM3/I" suffix denotes AEC-Q101 qualification, halogen-free construction, and 13-inch tape-and-reel packaging-features not guaranteed in base SM8S51A variants.
What is the reverse leakage current specification for SM8S51CAHM3/I at maximum operating temperature?
The SM8S51CAHM3/I specifies a maximum reverse leakage current (ID) of 10 μA at VWM = 51 V and TJ = 175 °C. This value is confirmed in the "ELECTRICAL CHARACTERISTICS" table on page 2 of the Vishay datasheet (Doc. 98229), under the column "MAXIMUM REVERSE LEAKAGE AT VWM TJ = 175 °C". This low high-temperature leakage ensures minimal standby power loss and stable voltage reference integrity in always-on automotive modules. The SM8S51CAHM3/I maintains this performance without derating across its full -55 °C to +175 °C junction temperature range.
SM8S51CAHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AB
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 80.1A
- Power - Peak Pulse:
- 6600W (6.6kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218AB
SM8S51CAHM3/I FAQ
1.How can I place an order for SM8S51CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM8S51CAHM3/I on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SM8S51CAHM3/I reliable?
The price and inventory of SM8S51CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM8S51CAHM3/I is usually 5 days.
3.What payment methods are accepted for SM8S51CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM8S51CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM8S51CAHM3/I?
SM8S51CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM8S51CAHM3/I order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SM8S51CAHM3/I?
For technical support, including SM8S51CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM8S51CAHM3/I requirements.
6.How does Aetrix verify that SM8S51CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SM8S51CAHM3/I products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SM8S51CAHM3/I meets industry standards.
7.What is the process for return or replacement of SM8S51CAHM3/I?
All SM8S51CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM8S51CAHM3/I, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SM8S51CAHM3/I part is unused and in its original packaging.
Return procedure for SM8S51CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM8S51CAHM3/I Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
