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Taiwan Semiconductor Corporation SMDJ40AH
- Part No.:
- SMDJ40AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ40AH.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:7,066
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Product details
Overview
SMDJ40AH from Taiwan Semiconductor is a unidirectional 3000W surface-mount transient voltage suppressor (TVS) diode with a 40V working stand-off voltage, 44.4–49.1V breakdown voltage at 1mA test current, and 64.5V maximum clamping voltage at 46.5A peak pulse current. It is AEC-Q101 qualified and designed for automotive and industrial power rail protection against ESD, load dump, and lightning-induced transients.
For engineers reviewing the SMDJ40AH datasheet, SMDJ40AH pinout, SMDJ40AH application, or SMDJ40AH equivalent, key selection criteria include its DO-214AB (SMC) package, 175°C junction temperature rating, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, fast sub-1ps response time, and unidirectional polarity marking.
Technical Context
The SMDJ40AH operates as a unidirectional avalanche diode that clamps transient overvoltages above its breakdown threshold while maintaining low leakage (<1µA at 40V) under normal operation. Its glass-passivated junction ensures stable VBR tolerance and long-term reliability in harsh environments.
Thermal performance is defined by RθJA = 75°C/W and RθJL = 15°C/W, enabling effective heat dissipation in high-power surge events. It supports single-pulse 3000W peak power per 1ms waveform (10/1000µs), with derating above 25°C ambient per published curves.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR @ IT=1mA | 44.4–49.1 V - Confirmed breakdown range ensuring reliable turn-on margin above VWM |
| VC @ IPPM=46.5A | 64.5 V - Clamping voltage during full-rated 3000W transient, limiting downstream stress |
| PPK | 3000 W - Peak pulse power handling capability per 1ms 10/1000µs waveform |
| IPPM | 46.5 A - Maximum non-repetitive peak pulse current supported without failure |
| TJ max | 175 °C - Maximum junction temperature enabling operation in under-hood automotive environments |
| Response time | <1.0 ps - Sub-picosecond avalanche response ensures protection before sensitive ICs are damaged |
Pinout & Package
Package: DO-214AB (SMC), surface-mount, unidirectional configuration with cathode band marking. Matte tin-plated leads, J-STD-002 solderable, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side | Connected to protected line (e.g., 12V battery rail); conducts during reverse-biased transients |
| Cathode | Ground/Reference side | Connected to system ground; defines unidirectional conduction path and polarity orientation |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing |
| Glass-passivated junction | Ensures stable VBR tolerance and resistance to humidity-induced parameter drift |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (line capacitance discharge) |
| UL 94V-0 molding compound | Flame-retardant encapsulation required for automotive and industrial safety certifications |
| J-STD-020 Level 1 MSL | Zero bake requirement prior to reflow, enabling direct placement in automated SMT lines |
Applications
| Automotive Power Rail Protection | Industrial DC Power Input Stage |
|---|---|
Use Scenario: Protecting 12V/24V vehicle electronics (ECUs, sensors, infotainment) from load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and input filter capacitor to clamp surges before LDOs or DC-DC converters. Use Value: Limits clamped voltage to 64.5V, well below typical 75V automotive IC absolute maximum ratings, preventing latch-up or gate oxide damage. | Use Scenario: Safeguarding programmable logic controllers (PLCs) and motor drives from switching noise and inductive kickback on 24V/48V supply inputs. IC Role / Device Role / Timing Role: Primary surge suppression device at front-end connector interface, coordinated with upstream fuses and downstream π-filters. Use Value: Withstands 3000W pulses without degradation, enabling robust field deployment in factory automation with frequent contactor switching. |
| Telecom Equipment DC Feeds | Consumer Electronics USB/Power Adapter Inputs |
Use Scenario: Protecting PoE-powered switches and base station remote radio units fed via 48V DC distribution. IC Role / Device Role / Timing Role: Standoff-clamp TVS on primary DC input, positioned ahead of DC-DC isolation stages and hot-swap controllers. Use Value: Fast <1ps response captures fast-rising transients from nearby lightning strikes or cable coupling, preserving signal integrity in data links. | Use Scenario: Secondary-level surge protection in AC-DC adapters and USB-C PD power bricks where space-constrained layouts demand high-power density. IC Role / Device Role / Timing Role: Final-stage TVS after bulk filtering but before secondary-side regulation, absorbing residual transients missed by MOVs or GDTs. Use Value: DO-214AB footprint enables compact layout; 6.5W steady-state power rating supports thermal management in sealed enclosures. |
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 SMAJ40A | Same DO-214AC (SMA) package; lower PPK = 400W; VC = 64.5V at 6.2A | Not suitable for 3000W ISO 7637-2 Pulse 5a (load dump); limited to lower-energy transients | Select SMDJ40AH when full automotive load dump immunity is required; SMAJ40A only for consumer-grade surge suppression. |
| ON Semiconductor SMCJ40A | Same DO-214AB (SMC) package; identical PPK = 3000W; VC = 64.5V at 46.5A; AEC-Q101 qualified | No functional difference; validated in same automotive subsystems (e.g., body control modules) | Drop-in alternative with identical electrical and mechanical specs; suitable for dual-sourcing programs requiring second-source validation. |
Compared with SMAJ40A and SMCJ40A, the SMDJ40AH delivers equivalent clamping performance and automotive qualification in the same SMC package, but differs in manufacturing origin and traceability-SMCJ40A offers direct second-source availability, while SMAJ40A requires redesign for higher-energy surge requirements.
Availability
SMDJ40AH is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, and telecom DC power feeds requiring stable component supply across multi-year production cycles.
Supply support for SMDJ40AH 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMDJ series was developed specifically for high-reliability automotive and industrial transient suppression, emphasizing AEC-Q101 compliance, ISO 7637-2 immunity, and robust thermal performance in surface-mount form factors.
FAQ
What is the polarity configuration of the SMDJ40AH?
The SMDJ40AH is a unidirectional TVS diode, with cathode indicated by a band on the DO-214AB (SMC) package. It conducts only during reverse-biased transients-forward voltage is 3.5V at 100A-making it suitable for DC power rail protection where polarity is fixed. Bidirectional variants use the "CAH" suffix (e.g., SMDJ40CAH).
Does the SMDJ40AH meet automotive qualification standards?
Yes, the SMDJ40AH is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b waveforms. Its 175°C maximum junction temperature, glass-passivated junction, and JESD201 Class 2 whisker resistance support under-hood and chassis-mounted automotive applications.
What is the maximum clamping voltage of the SMDJ40AH under rated surge conditions?
The SMDJ40AH has a maximum clamping voltage (VC) of 64.5V at 46.5A peak pulse current (IPPM), corresponding to its full 3000W peak power rating per 1ms 10/1000µs waveform. This value is guaranteed across temperature and process variation per the manufacturer's electrical specifications table.
Can the SMDJ40AH be used in bidirectional signal line protection?
No-the SMDJ40AH is unidirectional and not rated for symmetrical bipolar transients. For bidirectional protection (e.g., RS-485, CAN bus), use the SMDJ40CAH variant, which features matched breakdown in both directions and is marked with "DFR" coding. Using SMDJ40AH on AC or floating lines risks forward conduction and failure.
What is the thermal resistance from junction to ambient for the SMDJ40AH?
The SMDJ40AH has a typical junction-to-ambient thermal resistance (RθJA) of 75°C/W when mounted on a standard JEDEC 2-layer test board. Its junction-to-lead resistance (RθJL) is 15°C/W, indicating efficient heat transfer to PCB copper; actual values depend on pad layout, copper area, and airflow per the manufacturer's suggested footprint guidelines.
SMDJ40AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMDJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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):
- 46.5A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMDJ40AH FAQ
1.How can I place an order for SMDJ40AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ40AH 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 SMDJ40AH reliable?
The price and inventory of SMDJ40AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ40AH is usually 5 days.
3.What payment methods are accepted for SMDJ40AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ40AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ40AH?
SMDJ40AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ40AH 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 SMDJ40AH?
For technical support, including SMDJ40AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ40AH requirements.
6.How does Aetrix verify that SMDJ40AH is sourced from the original manufacturer or authorized distributors?
All SMDJ40AH 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 SMDJ40AH meets industry standards.
7.What is the process for return or replacement of SMDJ40AH?
All SMDJ40AH units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ40AH, 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 SMDJ40AH part is unused and in its original packaging.
Return procedure for SMDJ40AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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