My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ90A
- Part No.:
- SMAJ90A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ90A.pdf
- Description:
- TVS DIODE 90VWM 146VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,054
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ90A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in DC power lines and signal paths. It features a 90 V working stand-off voltage (VWM), 100–111 V breakdown voltage (VBR) at 1 mA test current, and clamps transients to ≤146 V at 2.1 A peak impulse current under 10/1000 µs waveform - enabling reliable protection of 90 V-rated systems such as industrial DC/DC converters and telecom power supplies.
For engineers reviewing the SMAJ90A datasheet, SMAJ90A pinout, SMAJ90A application, or SMAJ90A equivalent, key selection criteria include its DO-214AC (SMA) package compatibility with automated placement, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, 400 W peak pulse power rating (10/1000 µs), and <1 µA reverse leakage at 90 V - critical for low-power, high-reliability automotive and industrial designs.
Technical Context
The SMAJ90A operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology for stable breakdown behavior and fast response (<1.0 ps from 0 V to VBR min). Its clamping action begins at 100 V and limits transient energy within strict thermal limits defined by TJ max = 150 °C and steady-state power dissipation of 1 W.
Designed for single-die, single-direction surge suppression, it supports bidirectional applications only when paired with complementary devices or used in symmetrical configurations. Its DO-214AC (SMA) package provides mechanical robustness, UL 94V-0 flammability rating, and JESD201 Class 2 whisker resistance - meeting automotive-grade assembly and reliability requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 90 V - Maximum continuous DC or RMS voltage the device blocks without conduction; defines system operating voltage ceiling. |
| VBR @ IT=1 mA | 100–111 V - Voltage range at which avalanche breakdown initiates; ensures predictable turn-on above normal operating conditions. |
| VC @ IPPM | ≤146 V at 2.1 A - Clamped voltage during 10/1000 µs surge; determines maximum stress imposed on protected downstream circuitry. |
| PPPM | 400 W (10/1000 µs) - Peak transient energy handling capacity; sufficient for ISO 7637-2 Pulse 1 and Pulse 2b events in 12/24 V systems. |
| IR @ VWM | ≤1 µA - Reverse leakage at rated stand-off voltage; minimizes standby power loss in battery-backed or low-quiescent systems. |
| TJ max | 150 °C - Maximum junction temperature; enables operation in under-hood or enclosed industrial environments without derating below 25 °C ambient. |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single-ended cathode-marked configuration. Matte tin-plated leads, RoHS and halogen-free compliant, moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side | Connected to protected line (e.g., +VIN); conducts surge current toward cathode during overvoltage event. |
| Cathode | Clamp/Return side | Connected to ground or lower-potential rail; establishes reference for clamping and defines unidirectional polarity. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure. |
| Fast response time <1.0 ps | Enables suppression before sensitive ICs experience voltage overshoot - critical for protecting microcontrollers and ADC inputs. |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive load dump and inductive switching transients without external filtering or derating. |
| DO-214AC (SMA) package | Supports high-volume SMT assembly, meets IPC-A-610 Class 2/3 solderability standards, and enables compact PCB layout. |
Applications
| Automotive Power Distribution | Industrial DC/DC Converters |
|---|---|
Use Scenario: Protection of 24 V and 48 V power distribution networks against load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between battery rail and ECU input stage. Use Value: Limits clamped voltage to ≤146 V, preventing damage to 100 V-rated MOSFETs and gate drivers in power management ICs. |
Use Scenario: Input-side surge protection for isolated 90 V output DC/DC modules in factory automation controllers. IC Role / Device Role / Timing Role: Primary transient shunt on secondary-side output bus to safeguard downstream PLC I/O stages. Use Value: Withstands 400 W pulses per 10/1000 µs, maintaining regulation integrity during lightning-induced surges on long cable runs. |
| Telecom Power Supplies | LED Driver Front-Ends |
Use Scenario: Standby power rail protection in 48 V telecom rectifiers exposed to AC line transients and hot-swap events. IC Role / Device Role / Timing Role: Standoff-clamp TVS on +48 V input, positioned upstream of primary controller ICs. Use Value: ≤1 µA leakage at 90 V prevents unnecessary drain on backup batteries during extended idle periods. |
Use Scenario: Overvoltage guard for constant-current LED drivers powered from 90 V DC bus in streetlight systems. IC Role / Device Role / Timing Role: Line-to-ground TVS on driver input to absorb inductive kickback from magnetic components. Use Value: 150 °C max junction temperature allows direct mounting near heat-generating LED arrays without thermal 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 |
|---|---|---|---|
| SMAJ90 | Bidirectional variant; symmetric VBR (100–122 V) and higher clamping voltage (160 V at 1.9 A). | Required where AC-coupled or reversible polarity signals need protection (e.g., RS-485 buses). | Select SMAJ90 only if bidirectional clamping is explicitly needed; SMAJ90A offers tighter clamping and lower leakage for DC rails. |
| SMBJ90A | Same electrical specs but in larger DO-214AA (SMB) package; 600 W peak power rating (10/1000 µs). | Better suited for higher-energy transients or designs requiring margin beyond 400 W, e.g., heavy-duty motor drives. | Choose SMBJ90A when board space permits and surge energy exceeds SMAJ90A's 400 W limit; otherwise SMAJ90A optimizes footprint and cost. |
Compared with SMAJ90 and SMBJ90A, the SMAJ90A delivers optimal balance of low-leakage unidirectional clamping, compact DO-214AC packaging, and ISO 7637-2 compliance - making it the preferred choice for space-constrained 90 V DC power rail protection where precise voltage limiting and minimal standby loss are required.
Availability
SMAJ90A is available at Aetrix Electronics and suitable for automotive power distribution, industrial DC/DC converters, and telecom power supplies requiring stable component supply, full traceability, and lifecycle continuity.
Supply support for SMAJ90A 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 SMAJ series was developed specifically for high-reliability, surface-mount transient suppression in automotive and industrial environments - emphasizing ISO 7637-2 compliance, tight VBR tolerances, and robust packaging for automated manufacturing.
FAQ
What is the clamping voltage of SMAJ90A under standard 10/1000 µs surge conditions?
The SMAJ90A clamps to a maximum of 146 V when subjected to its rated peak impulse current of 2.1 A under the standardized 10/1000 µs waveform. This value is measured per JEDEC/IEC test conditions and represents the upper limit of voltage seen by downstream circuitry during transient events - critical for ensuring compatibility with 100 V-rated components in the protected system. The SMAJ90A datasheet specifies this VC@IPPM value at TA = 25°C.
Is SMAJ90A unidirectional or bidirectional, and how is polarity identified?
SMAJ90A is a unidirectional TVS diode, meaning it conducts only during reverse-biased overvoltage events. Polarity is marked by a cathode band on the DO-214AC (SMA) package body - the banded end connects to ground or the lower-potential node, while the anode connects to the line being protected. This configuration ensures low leakage during normal operation and precise clamping onset above 90 V. Bidirectional protection requires SMAJ90 instead.
Does SMAJ90A meet automotive transient immunity standards?
Yes, SMAJ90A meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (supply line inductance), Pulse 3a (capacitive coupled noise), and Pulse 3b (ground noise). Its 400 W peak pulse power rating and sub-1 µA leakage at 90 V enable direct integration into automotive ECUs and body control modules without additional filtering - verified per Taiwan Semiconductor's U2102 datasheet revision.
What is the maximum operating junction temperature for SMAJ90A?
The SMAJ90A has a maximum junction temperature (TJ max) of +150 °C, allowing reliable operation in high-ambient environments such as engine compartments or enclosed industrial enclosures. This rating is supported by its DO-214AC package thermal resistance and glass-passivated die construction. Derating curves in the datasheet define safe power dissipation limits above 25 °C ambient - essential for thermal design validation in continuous surge-prone applications.
How does SMAJ90A differ from SMAJ90 in practical circuit implementation?
SMAJ90A is unidirectional with asymmetric clamping (anode-to-cathode only), offering 146 V clamping at 2.1 A and ≤1 µA leakage at 90 V - ideal for DC power rails. SMAJ90 is bidirectional, clamping to 160 V at 1.9 A with higher leakage, and is used where signal lines reverse polarity or carry AC content. Circuit layout must respect polarity marking for SMAJ90A; SMAJ90 omits cathode banding and installs without orientation concern.
SMAJ90A 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):
- 90V
- Voltage - Breakdown (Min):
- 100V
- Voltage - Clamping (Max) @ Ipp:
- 146V
- Current - Peak Pulse (10/1000µs):
- 2.1A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ90A FAQ
1.How can I place an order for SMAJ90A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ90A 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 SMAJ90A reliable?
The price and inventory of SMAJ90A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ90A is usually 5 days.
3.What payment methods are accepted for SMAJ90A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ90A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ90A?
SMAJ90A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ90A 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 SMAJ90A?
For technical support, including SMAJ90A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ90A requirements.
6.How does Aetrix verify that SMAJ90A is sourced from the original manufacturer or authorized distributors?
All SMAJ90A 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 SMAJ90A meets industry standards.
7.What is the process for return or replacement of SMAJ90A?
All SMAJ90A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ90A, 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 SMAJ90A part is unused and in its original packaging.
Return procedure for SMAJ90A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ90A 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 …
