My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ40AHM3/I
- Part No.:
- SMAJ40AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40AHM3/I.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,243
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ40AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 40 V standoff voltage (VWM), 44.4–49.1 V breakdown voltage (VBR) at 1 mA, 64.5 V maximum clamping voltage (VC) at 6.2 A peak pulse current, and 400 W peak pulse power rating with 10/1000 μs waveform.
For engineers reviewing the SMAJ40AHM3/I datasheet, SMAJ40AHM3/I pinout, SMAJ40AHM3/I application, or SMAJ40AHM3/I equivalent, this device is selected for robust overvoltage protection on DC power rails and signal lines in automotive, industrial, and telecom systems where AEC-Q101 qualification, low-profile mounting, and fast response (<1 ns) are critical.
Technical Context
This unidirectional TVS diode operates as a voltage-clamped shunt protector: under normal conditions it presents high impedance (>1 MΩ leakage at 40 V), then rapidly avalanches below 64.5 V to divert transient energy away from downstream ICs or MOSFETs. Its glass-passivated junction ensures stable breakdown characteristics and long-term reliability under repetitive surge stress.
Designed for surface-mount assembly on standard PCB copper pads (0.2" × 0.2"), the SMAJ40AHM3/I delivers 400 W pulse power capability up to 150 °C junction temperature, with thermal resistance of 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead), enabling effective heat dissipation without heatsinking in typical board layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 40 V - Maximum continuous reverse operating voltage before significant leakage begins; defines safe DC rail margin. |
| VBR (Breakdown Voltage) | 44.4–49.1 V at 1 mA - Confirmed avalanche onset range; ensures reliable triggering above nominal system voltage. |
| VC (Clamping Voltage) | 64.5 V at 6.2 A - Peak voltage seen by protected circuit during 10/1000 μs transient; determines minimum IC survival margin. |
| PPPM (Peak Pulse Power) | 400 W - Sustained transient energy handling per IEC 61000-4-5 Level 4; supports repeated surge events at 0.01% duty cycle. |
| IPPM (Peak Pulse Current) | 6.2 A - Maximum surge current diverted during 10/1000 μs pulse; sets minimum trace width and fuse coordination. |
| TJmax | 150 °C - Maximum allowable junction temperature; enables operation in under-hood automotive environments. |
| Package | SMA (DO-214AC) - Low-profile, surface-mount package compatible with automated placement and reflow soldering (MSL Level 1). |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads; cathode indicated by band marking on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection point | Connected to ground or return path; completes clamping loop when transient exceeds VBR. |
| Cathode | High-side connection point | Connected to protected line (e.g., 40 V rail); polarity-sensitive-reversal prevents clamping function. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, humidity bias, and surge endurance per JESD22 standards. |
| 400 W peak pulse power (10/1000 μs) | Handles IEC 61000-4-5 Level 4 surges without degradation; rated at 300 W above 78 V, confirming robustness at higher voltages. |
| Fast response time (<1 ns) | Clamps transients before sensitive logic or analog circuits experience overvoltage stress; critical for protecting high-speed interfaces. |
| Halogen-free, RoHS-compliant (HM3 suffix) | Meets environmental compliance requirements for global automotive and industrial markets without compromising electrical performance. |
| Low incremental surge resistance | Minimizes voltage overshoot during high-di/dt events; ensures clamping stays within specified VC across full IPPM range. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs, body control modules, and infotainment power inputs from load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed between power rail and chassis ground to clamp transients before they reach LDOs or microcontrollers. Use Value: Withstands 400 W surges and maintains clamping at ≤64.5 V, ensuring downstream ICs survive 12 V system load dump events (up to 60 V, 400 ms). |
Use Scenario: Safeguarding analog sensor outputs (e.g., pressure, temperature) in PLCs and motor drives from ESD and inductive kickback. IC Role / Device Role / Timing Role: Low-capacitance TVS mounted directly at connector entry to suppress sub-100 ns ESD events and slow surges on 0–5 V or 4–20 mA lines. Use Value: Sub-1 ns response and 64.5 V clamping prevent latch-up or gate oxide damage in op-amps and ADC front-ends exposed to field wiring transients. |
| Telecom DC Power Input Protection | Consumer Device USB/DC Jack Protection |
|
Use Scenario: Securing -48 V or +24 V telecom rectifier outputs against lightning-induced surges on central office and remote radio head equipment. IC Role / Device Role / Timing Role: Primary-level TVS on input stage, coordinated with upstream fuses and secondary-stage polymer PTCs for staged protection. Use Value: 400 W rating and 150 °C max junction temperature support sustained operation in sealed, high-temperature telecom enclosures. |
Use Scenario: Hardening 5 V/9 V/12 V DC input jacks in smart speakers, set-top boxes, and gaming peripherals against user-insertion surges and ESD. IC Role / Device Role / Timing Role: First-line defense at board edge, absorbing human-body-model (HBM) ESD and accidental AC adapter misconnection events. Use Value: SMA package enables compact layout near connectors; halogen-free HM3 suffix satisfies consumer product environmental mandates without derating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40AHE3/I | Same electrical specs, but RoHS-compliant commercial grade (non-halogen-free); no AEC-Q101 qualification. | Approved for non-automotive industrial and consumer use; not suitable for automotive OEM or Tier-1 designs requiring AEC-Q101. | Select SMAJ40AHE3/I only if halogen-free content is not required and automotive qualification is unnecessary. |
| SMAJ43A HM3/I | Higher 43 V standoff voltage; VBR = 47.8–52.8 V; VC = 69.4 V at 5.8 A; same 400 W rating. | Better suited for 42 V nominal systems (e.g., 36 V battery packs); provides larger margin above 40 V rail but higher clamping voltage. | Choose SMAJ43AHM3/I when protecting 42 V systems where 40 V VWM would risk false triggering during normal ripple. |
Compared with SMAJ40AHM3/I, SMAJ40AHE3/I offers identical clamping and power handling but lacks halogen-free certification and AEC-Q101 validation, while SMAJ43AHM3/I trades lower VWM margin for higher system voltage compatibility-requiring careful evaluation of rail tolerance and transient amplitude.
Availability
SMAJ40AHM3/I is available at Aetrix Electronics and suitable for automotive ECU protection, industrial sensor interface hardening, and telecom DC input safeguarding requiring stable component supply, AEC-Q101 compliance, and halogen-free material content.
Supply support for SMAJ40AHM3/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 diodes, rectifiers, TVS devices, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series is engineered for high-energy transient suppression in harsh environments-targeting automotive, industrial, and telecom applications where consistent clamping, AEC-Q101 validation, and surface-mount manufacturability are mandatory.
FAQ
What is the clamping voltage of SMAJ40AHM3/I at its rated peak pulse current?
The SMAJ40AHM3/I has a maximum clamping voltage (VC) of 64.5 V at 6.2 A peak pulse current (IPPM) under 10/1000 μs waveform conditions. This value is measured per standard test methods and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ40AHM3/I maintains this clamping performance across its full operating temperature range and after repeated surge exposures, as verified in Vishay's AEC-Q101 qualification testing.
Is SMAJ40AHM3/I suitable for automotive applications?
Yes, SMAJ40AHM3/I is AEC-Q101 qualified and specifically designed for automotive use, including engine control units, body electronics, and infotainment systems. Its halogen-free (HM3) construction, 150 °C maximum junction temperature rating, and validated performance under temperature cycling, humidity bias, and surge stress meet OEM requirements. The SMAJ40AHM3/I is approved for placement on 12 V and 24 V power rails subject to ISO 7637-2 and ISO 16750-2 transient profiles.
How does the HM3 suffix affect the specifications of SMAJ40AHM3/I?
The HM3 suffix on SMAJ40AHM3/I denotes halogen-free, RoHS-compliant construction with JESD201 Class 2 whisker resistance, but it does not alter electrical parameters-VWM, VBR, VC, PPPM, and thermal ratings remain identical to non-HM3 variants. The HM3 designation reflects material composition compliance only; all performance data in the 88390 datasheet applies fully to SMAJ40AHM3/I, including AEC-Q101 qualification status and MSL Level 1 reflow compatibility.
What is the thermal resistance of SMAJ40AHM3/I, and how does it impact PCB layout?
The SMAJ40AHM3/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W and junction-to-lead resistance (RθJL) of 30 °C/W when mounted on 0.2" × 0.2" copper pads per Vishay's recommended layout. This means minimal copper area is needed for thermal management in most applications-no external heatsink is required. For high-reliability automotive use, maintaining the specified pad dimensions and solder coverage ensures the device sustains 400 W surge capability without exceeding 150 °C junction temperature.
Can SMAJ40AHM3/I be used in bidirectional configurations?
No, SMAJ40AHM3/I is a unidirectional TVS diode and must be used with correct polarity-cathode connected to the protected line, anode to ground. Bidirectional operation requires a CA-suffixed part such as SMAJ40CA. Using SMAJ40AHM3/I in reverse bias beyond its 40 V standoff will cause forward conduction (VF ≈ 3.5 V at 25 A), failing to suppress negative-going transients and potentially damaging the device or circuit. Always verify polarity during schematic capture and layout for SMAJ40AHM3/I.
SMAJ40AHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ40AHM3/I FAQ
1.How can I place an order for SMAJ40AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40AHM3/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 SMAJ40AHM3/I reliable?
The price and inventory of SMAJ40AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40AHM3/I is usually 5 days.
3.What payment methods are accepted for SMAJ40AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40AHM3/I?
SMAJ40AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40AHM3/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 SMAJ40AHM3/I?
For technical support, including SMAJ40AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40AHM3/I requirements.
6.How does Aetrix verify that SMAJ40AHM3/I is sourced from the original manufacturer or authorized distributors?
All SMAJ40AHM3/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 SMAJ40AHM3/I meets industry standards.
7.What is the process for return or replacement of SMAJ40AHM3/I?
All SMAJ40AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40AHM3/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 SMAJ40AHM3/I part is unused and in its original packaging.
Return procedure for SMAJ40AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ40AHM3/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 …
