My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SM5S78CAHM3/I
- Part No.:
- SM5S78CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S78CAHM3/I.pdf
- Description:
- 3600 W BI-DIRECTIONAL TVS IS DO-
- Quantity:
- Payment:
- Shipping:
Inventory:2,956
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM5S78CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for automotive load dump protection in 12 V/24 V systems. It features a 78.0 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR), 126 V maximum clamping voltage (VC) at 28.6 A peak pulse current, and 3600 W peak pulse power (10/1000 µs). Its DO-218AC package supports AEC-Q101 qualification and 175 °C junction operation.
For engineers reviewing the SM5S78CAHM3/I datasheet, SM5S78CAHM3/I pinout, SM5S78CAHM3/I application, or SM5S78CAHM3/I equivalent, this device is selected for high-reliability automotive power rail protection where ISO 7637-2 and ISO 16750-2 surge compliance, low leakage (<10 µA at VWM), and MSL Level 1 solderability are mandatory design requirements.
Technical Context
The SM5S78CAHM3/I employs an avalanche diode structure optimized for fast response (<1 ns) to transients induced by inductive load switching and alternator load dump events. Its bidirectional configuration enables symmetrical clamping without polarity sensitivity, and its thermal resistance RθJM of 0.45 °C/W ensures efficient heat transfer to the PCB metal heatsink pad.
Rated for continuous operation from –55 °C to +175 °C, it maintains stable VBR and VC across temperature with derated IPPM above 25 °C ambient. The DO-218AC package integrates a large-area metal cathode/anode heatsink terminal that serves as both electrical connection and primary thermal path-critical for sustaining 3600 W surges without thermal runaway.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78.0 V - Maximum continuous reverse operating voltage before clamping begins; defines system nominal rail tolerance margin. |
| VBR (min/typ/max) | 86.7 / 91.3 / 95.8 V - Breakdown threshold range at 5 mA test current; ensures reliable turn-on during overvoltage events. |
| VC @ IPPM | 126 V at 28.6 A - Clamped voltage under 10/1000 µs surge; determines protected circuit's maximum transient exposure. |
| PPPM (10/1000 µs) | 3600 W - Peak surge power handling capacity; validates suitability for severe automotive load dump per ISO 7637-2 Pulse 5a. |
| ID @ VWM | <10 µA - Reverse leakage at rated stand-off voltage; minimizes quiescent power loss in always-on vehicle modules. |
| TJ max. | +175 °C - Maximum junction temperature; enables placement near hot engine control units without derating. |
| Package | DO-218AC - Surface-mount package with integrated metal heatsink pad; requires IPC 7351-compliant footprint for thermal reliability. |
Pinout & Package
DO-218AC package: two-terminal SMD device with exposed metal cathode/anode heatsink pad (Lead 2) and molded anode lead (Lead 1); polarity is bidirectional-no cathode band marking required.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Anode connection (molded lead) | Primary signal-side connection; soldered to PCB trace carrying protected line (e.g., battery feed). |
| Lead 2 / Metal Heatsink Pad | Cathode/anode common terminal | Large copper pad serving as both electrical return path and primary thermal interface to PCB ground plane or heatsink copper area. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing-required for ECUs, body controllers, and ADAS modules. |
| ISO 7637-2 & ISO 16750-2 compliant | Passes Pulse 5a (load dump) and Pulse 1/2a/3a transient immunity tests-enables direct integration into OEM power distribution designs. |
| MSL Level 1 (245 °C peak) | Compatible with standard lead-free reflow profiles without moisture sensitivity concerns-eliminates baking requirement pre-assembly. |
| Halogen-free, RoHS-compliant (M3) | Meets global environmental regulations and automotive material restrictions (e.g., VW 80101); supports sustainable manufacturing programs. |
| Junction-to-mount thermal resistance (RθJM) | 0.45 °C/W - Enables >90% of surge energy to dissipate directly into PCB copper, reducing thermal stress on die during repeated transients. |
Applications
| Engine Control Unit (ECU) Power Input Protection | Automotive Infotainment System DC Supply |
|---|---|
Use Scenario: Protects 12 V input rails of gasoline/diesel engine control units against alternator load dump surges up to 35 V for 400 ms. IC Role / Device Role / Timing Role: Primary clamping element placed upstream of DC/DC converters and microcontrollers. Use Value: Limits transient voltage to ≤126 V, preventing latch-up or gate oxide damage in downstream 3.3 V/5 V logic and power ICs. |
Use Scenario: Shields infotainment head unit power supply from ignition-switching transients and battery jump-start spikes. IC Role / Device Role / Timing Role: Standoff protector on main 12 V input before buck regulator and audio amplifiers. Use Value: Maintains <10 µA leakage at 78 V, avoiding standby current penalty while clamping 3600 W surges within 1 ns. |
| ADAS Camera Module Power Line | Electric Power Steering (EPS) Control Board |
Use Scenario: Secures 12 V supply to forward-facing camera modules exposed to harsh under-hood environments and EMI-rich CAN bus zones. IC Role / Device Role / Timing Role: First-line TVS on camera module PCB, mounted adjacent to connector entry point. Use Value: Withstands 175 °C junction temperature and passes ISO 16750-2 high-temperature surge tests-ensures reliability in sealed enclosures. |
Use Scenario: Guards EPS motor driver power stage against inductive kickback from 3-phase BLDC motor commutation and battery reversal events. IC Role / Device Role / Timing Role: Bidirectional clamp on high-current 12 V/24 V power rail feeding gate drivers and current sensors. Use Value: DO-218AC metal pad conducts >95% of surge energy into chassis ground plane, preventing localized PCB delamination. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ78CA | Same DO-214AC package; lower PPPM (400 W vs. 3600 W); VBR 86.7–95.8 V; clamps at 126 V but only up to 3.2 A. | Not suitable for load dump-limited to ESD and low-energy transients; lacks AEC-Q101 and ISO 7637-2 validation. | Select only for cost-sensitive non-automotive industrial I/O protection where surge energy is <500 W. |
| ON Semiconductor 1.5KE78CA | Through-hole DO-201 package; 3600 W rating; VBR 86.7–95.8 V; same VC (126 V); no AEC-Q101 or MSL Level 1 rating. | Requires wave soldering or hand assembly; incompatible with automated SMT lines; unsuitable for under-hood vibration environments. | Use only for legacy through-hole designs or prototyping where board space and thermal performance are secondary to procurement simplicity. |
Compared with SMAJ78CA and 1.5KE78CA, the SM5S78CAHM3/I uniquely combines SMT manufacturability, 3600 W automotive-grade surge capability, AEC-Q101 qualification, and DO-218AC thermal efficiency-making it the only option qualified for production automotive power rail protection requiring zero layout compromise.
Availability
SM5S78CAHM3/I is available at Aetrix Electronics and suitable for automotive electronic control units, ADAS camera modules, infotainment head units, and electric power steering systems requiring stable component supply across multi-year vehicle production cycles.
Supply support for SM5S78CAHM3/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, optoelectronics, and passive components for automotive, industrial, and computing markets.
The SM5SxxCA family is engineered specifically for automotive power rail transient suppression, emphasizing AEC-Q101 compliance, high-temperature stability, and robust surge handling in compact surface-mount packages.
FAQ
What is the maximum clamping voltage of the SM5S78CAHM3/I under a 10/1000 µs surge?
The SM5S78CAHM3/I has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current of 28.6 A under the standardized 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and is critical for ensuring downstream ICs remain within their absolute maximum voltage ratings during load dump events. The SM5S78CAHM3/I achieves this clamping performance while maintaining low leakage and high thermal robustness.
Is the SM5S78CAHM3/I suitable for use in under-hood automotive applications?
Yes, the SM5S78CAHM3/I is explicitly qualified for under-hood use: it carries AEC-Q101 certification, operates continuously from –55 °C to +175 °C, and meets ISO 7637-2 Pulse 5a load dump requirements. Its DO-218AC package transfers heat efficiently via the metal heatsink pad into the PCB, and its halogen-free M3 construction complies with automotive material standards. The SM5S78CAHM3/I is routinely deployed in engine control units and transmission control modules.
Does the SM5S78CAHM3/I have polarity markings on the package?
No, the SM5S78CAHM3/I is a bidirectional TVS diode and carries no cathode band or polarity marking on the DO-218AC case. Its symmetrical avalanche structure allows installation in either orientation on the PCB without affecting clamping behavior. This simplifies layout and eliminates orientation-related assembly errors-particularly valuable in high-volume automotive SMT lines where the SM5S78CAHM3/I is commonly used.
What is the thermal resistance from junction to mount (RθJM) for the SM5S78CAHM3/I?
The SM5S78CAHM3/I has a typical junction-to-mount thermal resistance (RθJM) of 0.45 °C/W, measured using JEDEC® 51-14 TDIM methodology. This low value reflects the efficient thermal path from the silicon die through the metal heatsink pad (Lead 2) directly into the PCB copper. When mounted on a 2 oz. FR4 board with recommended pad layout, this enables the SM5S78CAHM3/I to sustain repeated 3600 W surges without exceeding 175 °C junction temperature.
How does the SM5S78CAHM3/I differ from standard SMAJ-series TVS diodes?
The SM5S78CAHM3/I differs from SMAJ78CA in three key ways: it delivers 3600 W peak pulse power (vs. 400 W), uses the thermally superior DO-218AC package with metal heatsink pad (vs. DO-214AC plastic body), and is fully AEC-Q101 qualified and ISO 7637-2 compliant (SMAJ78CA is not). These distinctions make the SM5S78CAHM3/I suitable for production automotive load dump protection, whereas SMAJ78CA is limited to low-energy ESD and board-level transient suppression.
SM5S78CAHM3/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):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 28.6A
- Power - Peak Pulse:
- 3600W (3.6kW)
- 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
SM5S78CAHM3/I FAQ
1.How can I place an order for SM5S78CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S78CAHM3/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 SM5S78CAHM3/I reliable?
The price and inventory of SM5S78CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S78CAHM3/I is usually 5 days.
3.What payment methods are accepted for SM5S78CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S78CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S78CAHM3/I?
SM5S78CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S78CAHM3/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 SM5S78CAHM3/I?
For technical support, including SM5S78CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S78CAHM3/I requirements.
6.How does Aetrix verify that SM5S78CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SM5S78CAHM3/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 SM5S78CAHM3/I meets industry standards.
7.What is the process for return or replacement of SM5S78CAHM3/I?
All SM5S78CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM5S78CAHM3/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 SM5S78CAHM3/I part is unused and in its original packaging.
Return procedure for SM5S78CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S78CAHM3/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 …
