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Vishay General Semiconductor - Diodes Division SM5S40CAHM3/I
- Part No.:
- SM5S40CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S40CAHM3/I.pdf
- Description:
- 3600 W BI-DIRECTIONAL TVS IS DO-
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
SM5S40CAHM3/I from Vishay General Semiconductor is a surface-mount bidirectional PAR® transient voltage suppressor (TVS) designed for automotive load dump protection in 12 V/24 V systems. It features a 44.4–49.1 V breakdown voltage (VBR), 40 V stand-off voltage (VWM), 64.5 V maximum clamping voltage (VC) at 55.8 A peak pulse current, and 3600 W peak pulse power (10/1000 µs). Its DO-218AC package supports high-reliability underhood applications.
For engineers reviewing the SM5S40CAHM3/I datasheet, SM5S40CAHM3/I pinout, SM5S40CAHM3/I application, or SM5S40CAHM3/I equivalent, this device is selected for ISO 7637-2/ISO 16750-2-compliant surge suppression, AEC-Q101 qualification, TJ = 175 °C operation, low leakage (<10 µA at VWM), and halogen-free RoHS-compliant construction.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector, activating when reverse transients exceed its 40 V stand-off threshold to divert surge energy away from downstream circuitry. Its bidirectional architecture enables symmetrical clamping for both positive and negative transients without polarity marking.
Thermal design is enabled by ultra-low junction-to-mount thermal resistance (RθJM = 0.45 °C/W) and DO-218AC's integrated metal heatsink terminal, allowing effective power dissipation on standard FR4 PCBs without external heatsinking. It sustains 5 W steady-state power at 25 °C ambient with derating above that temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 44.4 / 46.8 / 49.1 V - ensures reliable turn-on above system nominal voltage while avoiding false triggering during normal operation |
| VWM | 40 V - maximum continuous reverse operating voltage compatible with 24 V automotive systems including load dump overshoot margins |
| VC @ IPPM | 64.5 V at 55.8 A (10/1000 µs) - clamps destructive transients below IC damage thresholds in protected circuits |
| PPPM (10/1000 µs) | 3600 W - handles severe ISO 7637-2 Pulse 5a load dump events without failure |
| ID @ VWM | <10 µA at 25 °C - minimizes standby power loss and avoids interference with high-impedance sensing nodes |
| TJ max. | 175 °C - supports underhood placement in engine control units and body electronics without thermal derating penalties |
| Package | DO-218AC - surface-mount package with integral metal heatsink terminal (Lead 2) enabling direct thermal coupling to PCB copper |
Pinout & Package
DO-218AC package features two terminals: Lead 1 (anode/cathode-indifferent) and Lead 2 (metal heatsink terminal). The device is bidirectional with no polarity marking; both terminals function identically for transient conduction. Thermal performance relies on soldering Lead 2 to a large copper pour for heat spreading.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Anode/Cathode (bidirectional) | Primary surge conduction path; connects to protected line (e.g., battery rail); no cathode band required |
| Lead 2 | Metal Heatsink Terminal | Low-thermal-resistance path to PCB copper; must be soldered to ≥100 mm² copper area for rated power handling |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability across -55 °C to +175 °C, including temperature cycling, HTRB, and ESD testing |
| Meets ISO 7637-2 & ISO 16750-2 | Passes Pulse 5a (load dump) and Pulse 1/2a/3a transient immunity tests per automotive OEM requirements |
| MSL Level 1 (J-STD-020) | Reflow-compatible up to 245 °C peak without moisture sensitivity concerns - suitable for standard SMT assembly |
| Halogen-free, RoHS-compliant (M3) | Complies with automotive environmental standards and end-of-life recycling mandates without compromising surge robustness |
| RθJM = 0.45 °C/W | Enables >90% of rated 3600 W pulse power to be dissipated through the metal heatsink terminal into PCB copper |
Applications
| Engine Control Unit (ECU) Power Input Protection | Body Control Module (BCM) CAN Bus Line Protection |
|---|---|
|
Use Scenario: Protects 12 V supply input of engine control units against alternator load dump transients up to 40 V overshoot. IC Role / Device Role / Timing Role: Shunt TVS diode clamping transients within nanoseconds to limit voltage seen by DC/DC converters and microcontrollers. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V regulators and MCU I/Os during ISO 7637-2 Pulse 5a events. |
Use Scenario: Shields high-speed CAN FD transceivers from coupled transients induced by nearby solenoid switching in vehicle body networks. IC Role / Device Role / Timing Role: Bidirectional clamping element placed between CAN_H/CAN_L differential pair and ground to suppress common-mode surges. Use Value: Maintains signal integrity below 1 V differential disturbance threshold while surviving 2200 W (10/10 ms) surge pulses. |
| ADAS Camera Power Rail Protection | Electric Power Steering (EPS) Motor Driver Stage |
|
Use Scenario: Secures 5 V or 12 V bias rails feeding image sensors and ISP processors in forward-facing ADAS cameras exposed to underhood EMI. IC Role / Device Role / Timing Role: Fast-response voltage clamp placed upstream of LDOs to absorb sub-100 ns ESD and switching noise spikes. Use Value: Eliminates pixel corruption and frame drop caused by VCC sag or overvoltage exceeding 64.5 V clamping limit. |
Use Scenario: Guards gate drivers and current sense amplifiers in EPS motor control modules subjected to inductive kickback from 3-phase BLDC commutation. IC Role / Device Role / Timing Role: High-energy TVS connected across H-bridge supply rails to clamp flyback voltages during PWM dead-time transitions. Use Value: Enables robust operation at 175 °C junction temperature without derating, critical for sealed EPS housing environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40CA | DO-214AC package; lower PPPM = 400 W (10/1000 µs); RθJA = 100 °C/W; not AEC-Q101 qualified | Limited to non-automotive industrial or consumer applications requiring <500 W surge handling | Select SMAJ40CA only for cost-sensitive, non-automotive designs where 3600 W capability and 175 °C operation are unnecessary |
| TPSMD40CA | DO-218AC package; same PPPM = 3600 W; VC = 69.4 V at 51.9 A; AEC-Q101 qualified; slightly higher clamping voltage | Acceptable where 4.9 V higher clamping is tolerable for protected ICs with wider VIN range | Choose TPSMD40CA if board layout allows marginally higher clamping or if dual-sourcing from Texas Instruments is preferred |
Compared with SMAJ40CA and TPSMD40CA, SM5S40CAHM3/I delivers superior thermal performance (RθJM = 0.45 °C/W vs. >1.0 °C/W), tighter VC tolerance (64.5 V vs. 69.4 V), and guaranteed AEC-Q101 compliance - making it the optimal choice for space-constrained, high-temperature automotive power rail protection.
Availability
SM5S40CAHM3/I is available at Aetrix Electronics and suitable for automotive ECU power input protection, body control module CAN bus protection, ADAS camera power rail hardening, and electric power steering motor driver stage safeguarding requiring stable component supply across multi-year production cycles.
Supply support for SM5S40CAHM3/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-grade transient suppression - combining AEC-Q101 qualification, 175 °C operation, and DO-218AC thermal efficiency to meet stringent OEM load dump and ESD immunity requirements.
FAQ
What is the maximum clamping voltage of SM5S40CAHM3/I at its rated peak pulse current?
The SM5S40CAHM3/I has a maximum clamping voltage (VC) of 64.5 V when subjected to its rated 55.8 A peak pulse current (IPPM) under the standard 10/1000 µs waveform. This value is measured per Figure 4 in the Vishay datasheet 98458 and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The SM5S40CAHM3/I maintains this clamping performance across its full operating temperature range.
Is SM5S40CAHM3/I suitable for 24 V automotive systems?
Yes, SM5S40CAHM3/I is explicitly designed for 24 V automotive systems. Its 40 V stand-off voltage (VWM) provides adequate margin above nominal 24 V rail while remaining below the 64.5 V clamping threshold, ensuring compatibility with ISO 7637-2 Pulse 5a load dump profiles. The SM5S40CAHM3/I also meets AEC-Q101 qualification and operates reliably from -55 °C to +175 °C - fulfilling underhood environmental requirements.
Does SM5S40CAHM3/I require a cathode marking for PCB layout?
No, SM5S40CAHM3/I is a bidirectional TVS diode with no polarity marking required. The DO-218AC package has identical electrical behavior on both terminals, and the device clamps symmetrically for positive and negative transients. PCB layout for SM5S40CAHM3/I treats both leads as interchangeable - though Lead 2 (metal heatsink) must be connected to a large copper area for thermal performance.
What is the thermal resistance from junction to mount (RθJM) for SM5S40CAHM3/I?
The SM5S40CAHM3/I has a typical junction-to-mount thermal resistance (RθJM) of 0.45 °C/W, as specified in the Vishay datasheet 98458, Section "THERMAL CHARACTERISTICS". This ultra-low value is achieved via the DO-218AC package's integrated metal heatsink terminal (Lead 2), which enables efficient heat transfer directly into PCB copper. This parameter is critical for sustaining high pulse power without exceeding the 175 °C maximum junction temperature.
How does SM5S40CAHM3/I differ from standard SMAJ-series TVS diodes?
SM5S40CAHM3/I differs from SMAJ-series devices in three key ways: it uses the thermally superior DO-218AC package (vs. DO-214AC), delivers 3600 W peak pulse power (vs. 400 W for SMAJ40CA), and is AEC-Q101 qualified (SMAJ40CA is not). These differences make SM5S40CAHM3/I suitable for demanding automotive applications where SMAJ40CA would fail thermally or lack qualification. The SM5S40CAHM3/I also features halogen-free M3 construction and MSL Level 1 reflow compatibility.
SM5S40CAHM3/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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 55.8A
- 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
SM5S40CAHM3/I FAQ
1.How can I place an order for SM5S40CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S40CAHM3/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 SM5S40CAHM3/I reliable?
The price and inventory of SM5S40CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S40CAHM3/I is usually 5 days.
3.What payment methods are accepted for SM5S40CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S40CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S40CAHM3/I?
SM5S40CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S40CAHM3/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 SM5S40CAHM3/I?
For technical support, including SM5S40CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S40CAHM3/I requirements.
6.How does Aetrix verify that SM5S40CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SM5S40CAHM3/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 SM5S40CAHM3/I meets industry standards.
7.What is the process for return or replacement of SM5S40CAHM3/I?
All SM5S40CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM5S40CAHM3/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 SM5S40CAHM3/I part is unused and in its original packaging.
Return procedure for SM5S40CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM5S40CAHM3/I Tags
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