My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ30H
- Part No.:
- SMAJ30H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ30H.pdf
- Description:
- TVS DIODE 30VWM 53.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,558
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ30H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in DC power rails and signal lines. It features a 30 V working stand-off voltage (VWM), 33.3–40.7 V breakdown voltage (VBR), 53.5 V maximum clamping voltage (VC) at 7.5 A peak pulse current, and 400 W peak pulse power rating per 10/1000 µs waveform - deployed in automotive-grade SMPS, on-board DC/DC converters, and lighting control circuits.
For engineers reviewing the SMAJ30H datasheet, SMAJ30H pinout, SMAJ30H application, or SMAJ30H equivalent, key selection criteria include its AEC-Q101 qualification, DO-214AC (SMA) package compatibility, low leakage (<1 µA at 30 V), sub-1 ps response time, and ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance for automotive transients.
Technical Context
The SMAJ30H operates as a unidirectional avalanche diode with glass-passivated junction, optimized for fast clamping of ESD and surge events. Its electrical behavior follows standardized TVS diode characteristics: reverse-biased operation up to VWM = 30 V, sharp transition into conduction at VBR (min 33.3 V, max 40.7 V @ 1 mA), and stable clamping at VC = 53.5 V under 7.5 A 10/1000 µs impulse.
Thermal design is constrained by TJMAX = 150 °C and steady-state power dissipation of 1 W. The device meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity - enabling direct placement in high-reliability automated SMT lines without baking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 30 V - Maximum continuous reverse operating voltage before significant leakage begins; defines safe DC rail margin. |
| VBR @ IT = 1 mA | 33.3–40.7 V - Breakdown threshold range; ensures reliable turn-on during overvoltage while avoiding false triggering. |
| VC @ IPPM = 7.5 A | 53.5 V - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to ≤53.5 V. |
| PPPM | 400 W - Peak pulse power handling (10/1000 µs); supports automotive load-dump and ISO 7637-2 Pulse 5a. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage at rated stand-off; preserves efficiency in battery-powered systems. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline; compatible with IPC-7351B footprint and standard reflow profiles. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Forward current input / Surge return path | Connected to protected circuit ground or low-side return; completes clamping loop during transient. |
| Cathode (banded end) | Reverse-biased protection node | Connected to line being protected (e.g., +30 V rail); conducts when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood and powertrain applications per stress test requirements (HTOL, TC, HTRB). |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal cycling and humidity. |
| Fast response time <1.0 ps | Clamps ESD and fast transients before sensitive logic or analog circuitry sustains damage. |
| ISO 7637-2 compliant | Withstands defined automotive transient pulses (Pulse 1, 2a, 2b, 3a, 3b) without degradation or failure. |
| Halogen-free & RoHS compliant | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for environmentally restricted substances. |
Applications
| Automotive On-Board DC/DC Converters | Industrial Switching Mode Power Supplies |
|---|---|
Use Scenario: Protecting 24 V input stage of buck converter powering ADAS camera modules against load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VIN and GND to clamp transients before input capacitor and controller IC. Use Value: Limits voltage seen by controller to ≤53.5 V during 400 W 10/1000 µs surge, preventing latch-up or gate oxide damage. | Use Scenario: Input rail protection in DIN-rail mounted 48 V to 12 V industrial SMPS used in PLC backplanes. IC Role / Device Role / Timing Role: Primary surge suppression element at AC-DC rectifier output or DC input filter stage. Use Value: Withstands repetitive 300–400 W surges per IEC 61000-4-5 while maintaining <1 µA leakage at 30 V nominal operation. |
| LED Driver Lighting Systems | Automotive Body Control Modules (BCM) |
Use Scenario: Overvoltage protection for constant-current LED driver ICs in commercial streetlight fixtures exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Parallel-connected TVS across driver input terminals to shunt surge energy to ground. Use Value: Clamps induced transients to 53.5 V within <1 ps, preserving driver IC integrity and avoiding LED string current disruption. | Use Scenario: Protection of LIN bus transceiver supply pins and sensor interface lines in BCMs subjected to battery reversal and cranking transients. IC Role / Device Role / Timing Role: Standoff-rated TVS on 12 V supply rail and low-voltage sensor inputs (e.g., temperature, door switch). Use Value: Maintains ≤1 µA leakage at 30 V stand-off while clamping ISO 7637-2 Pulse 2b (inductive switching) to safe levels for 5 V logic interfaces. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ30AH | Narrower VBR range (33.3–36.8 V vs. 33.3–40.7 V); tighter tolerance improves consistency in precision clamping designs. | Better suited for systems requiring tighter VBR distribution across production lots, e.g., safety-critical sensor power rails. | Select SMAJ30AH when statistical VBR control is prioritized over absolute maximum surge margin. |
| SMBJ30H | Same VWM/VBR/VC specs but in DO-214AA (SMB) package - 2.5 mm wider body, higher thermal mass, 600 W PPPM. | Preferred where board space allows larger footprint and higher surge endurance is required (e.g., front-end power entry). | Choose SMBJ30H only if layout permits SMB package and system-level surge testing demands >400 W capability. |
Compared with SMAJ30AH and SMBJ30H, the SMAJ30H offers the broadest VBR tolerance and smallest DO-214AC footprint - making it optimal for cost-sensitive, space-constrained automotive and industrial DC/DC applications where 400 W surge rating suffices.
Availability
SMAJ30H is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial switching mode power supplies, and LED driver lighting systems requiring stable component supply with AEC-Q101 assurance and full traceability.
Supply support for SMAJ30H 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 Company (TSC) is a vertically integrated Taiwanese manufacturer specializing in discrete semiconductors, including TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101 validation capability.
The SMAJ series was developed specifically for automotive and industrial transient suppression - emphasizing rugged packaging, fast response, and compliance with ISO 7637-2 and AEC-Q101 for under-hood and powertrain environments.
FAQ
What is the maximum clamping voltage of SMAJ30H under standard test conditions?
The SMAJ30H has a maximum clamping voltage (VC) of 53.5 V when subjected to a 7.5 A peak pulse current with a 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees that protected downstream circuitry will not experience voltages exceeding 53.5 V during specified surge events. The SMAJ30H maintains this clamping performance across its full operating temperature range of –55 °C to +150 °C.
Is SMAJ30H suitable for bidirectional transient protection?
No, SMAJ30H is a unidirectional TVS diode intended for DC rail protection with defined polarity. For bidirectional applications, Taiwan Semiconductor specifies the SMAJ30CH variant (with CH suffix), which provides symmetrical clamping in both directions. Using SMAJ30H in a bidirectional configuration would result in forward conduction during negative transients, potentially damaging the device or failing to protect the circuit.
Does SMAJ30H meet automotive qualification standards?
Yes, SMAJ30H is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for automotive electrical disturbances. Its construction - including glass-passivated junction, DO-214AC molding, and JESD201 Class 2 whisker resistance - supports deployment in engine control units, body control modules, and ADAS power supplies where reliability under thermal and mechanical stress is mandatory. The SMAJ30H data sheet explicitly cites AEC-Q101 compliance in its FEATURES section.
What is the reverse leakage current specification for SMAJ30H at its working voltage?
The SMAJ30H exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its rated working stand-off voltage of 30 V, tested at 25 °C. This ultra-low leakage ensures minimal power loss in always-on systems such as automotive body electronics and battery-backed lighting controllers. Leakage remains below 5 µA up to 125 °C, supporting stable operation in high-temperature environments without compromising efficiency.
Can SMAJ30H be used in place of SMAJ30AH in an existing design?
Yes, SMAJ30H can replace SMAJ30AH in most designs, but with trade-offs: SMAJ30H has a wider VBR range (33.3–40.7 V) versus SMAJ30AH's tighter 33.3–36.8 V range. This means SMAJ30H may trigger later under marginal overvoltage, offering greater noise immunity but slightly reduced protection margin. System validation under worst-case VBR and VC should be performed. Both share identical DO-214AC package, pinout, and thermal ratings - no PCB changes are needed.
SMAJ30H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 30V
- Voltage - Breakdown (Min):
- 33.3V
- Voltage - Clamping (Max) @ Ipp:
- 53.5V
- Current - Peak Pulse (10/1000µs):
- 7.5A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ30H FAQ
1.How can I place an order for SMAJ30H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ30H 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 SMAJ30H reliable?
The price and inventory of SMAJ30H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ30H is usually 5 days.
3.What payment methods are accepted for SMAJ30H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ30H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ30H?
SMAJ30H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ30H 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 SMAJ30H?
For technical support, including SMAJ30H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ30H requirements.
6.How does Aetrix verify that SMAJ30H is sourced from the original manufacturer or authorized distributors?
All SMAJ30H 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 SMAJ30H meets industry standards.
7.What is the process for return or replacement of SMAJ30H?
All SMAJ30H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ30H, 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 SMAJ30H part is unused and in its original packaging.
Return procedure for SMAJ30H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ30H 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 …
