My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ100
- Part No.:
- SMAJ100
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ100.pdf
- Description:
- 300W, 123.5V, 10%, UNIDIRECTIONA
- Quantity:
- Payment:
- Shipping:
Inventory:9,545
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ100 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 100 V working stand-off voltage (VWM), 111–136 V breakdown voltage (VBR), 179 V maximum clamping voltage (VC) at 1.7 A peak impulse current, and 400 W peak pulse power rating per 10/1000 µs waveform - deployed in switching mode power supplies and on-board DC/DC converters.
For engineers reviewing the SMAJ100 datasheet, SMAJ100 pinout, SMAJ100 application, or SMAJ100 equivalent, key selection criteria include its DO-214AC (SMA) package compatibility, unidirectional polarity marking, 1 µA max reverse leakage at 100 V, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, and junction temperature range of –55 °C to +150 °C.
Technical Context
The SMAJ100 operates as a unidirectional avalanche diode with glass-passivated junction, enabling fast response (<1.0 ps from 0 V to VBR min) and stable clamping under repetitive transients. Its single-die DO-214AC construction supports automated placement and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements.
It delivers 400 W peak pulse power at TA = 25 °C (derated above ambient), with steady-state power dissipation of 1 W and 40 A peak forward surge capability (8.3 ms half-sine). Polarity is marked by cathode band; moisture sensitivity level is J-STD-020 Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 100 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR @ IT = 1 mA | 111–136 V - Breakdown voltage range confirming reliable avalanche turn-on threshold |
| VC @ IPPM = 1.7 A | 179 V - Clamped voltage during 10/1000 µs transient, limiting downstream stress |
| PPPM | 400 W - Peak pulse power handling per standard 10/1000 µs waveform |
| IR @ VWM | ≤1 µA - Low leakage ensures minimal standby power loss in high-impedance circuits |
| TJ Range | –55 °C to +150 °C - Enables operation in automotive under-hood and industrial environments |
| Package | DO-214AC (SMA) - Standardized surface-mount footprint compatible with IPC-7351B land patterns |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, cathode indicated by a band on the body. Terminal polarity is unidirectional; anode and cathode are defined by physical marking - no internal circuitry beyond the single PN junction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Current entry terminal in forward bias | Connected to lower-potential side of protected line; enables low VF (3.5 V @ 25 A) during surge conduction |
| Cathode (banded end) | Current exit terminal in forward bias; reverse-biased during clamping | Connected to higher-potential rail (e.g., VIN); defines polarity-sensitive placement on PCB |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Ensures long-term stability and reduced parameter drift under thermal cycling and humidity exposure |
| Fast response time <1.0 ps | Clamps ESD and fast transients before sensitive ICs experience overstress |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive load dump and inductive switching immunity without external filtering |
| RoHS & halogen-free (IEC 61249-2-21) | Meets global environmental regulations and enables use in consumer and industrial green designs |
| J-STD-020 Level 1 moisture sensitivity | Allows unlimited floor life and standard reflow without baking or special handling |
Applications
| Automotive Power Rail Protection | Industrial SMPS Input Stage |
|---|---|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs against load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input rail and ground to clamp surges up to ±100 V. Use Value: Limits peak voltage to 179 V during 10/1000 µs pulses, safeguarding downstream regulators and microcontrollers. |
Use Scenario: Safeguarding AC-DC adapter primary-side rectifier output against switching spikes. IC Role / Device Role / Timing Role: Standoff-rated TVS absorbing repetitive flyback energy and line transients. Use Value: Withstands 400 W peak power and 40 A surge current, eliminating need for redundant snubbers. |
| LED Driver Overvoltage Clamp | On-Board DC/DC Converter Input |
Use Scenario: Preventing LED string damage from inductive kickback in constant-current drivers. IC Role / Device Role / Timing Role: Fast-clamping TVS across driver output to absorb inductive energy during MOSFET turn-off. Use Value: Sub-nanosecond response ensures clamping occurs before LED forward voltage exceeds absolute max rating. |
Use Scenario: Securing 48 V-to-12 V buck converter input against bus transients in telecom equipment. IC Role / Device Role / Timing Role: Primary-side transient suppressor placed upstream of input filter capacitor. Use Value: 100 V VWM allows margin above nominal 48 V rail while maintaining low leakage (≤1 µA). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ100A | Lower VBR range (111–123 V), tighter tolerance; 162 V clamping vs. 179 V | Better suited for systems requiring tighter clamping margin near 100 V rail | Select SMAJ100A when lower VC and tighter VBR distribution improve system-level surge margin |
| SMBJ100 | Same VWM/VBR/VC, but SMB package (DO-214AA) - 2.5 mm wider body, 0.5 mm taller | Requires PCB pad revision; offers 600 W peak power (vs. 400 W), higher IFSM (100 A) | Choose SMBJ100 only if higher surge rating justifies layout change and increased board area |
Compared with SMAJ100, the SMAJ100A provides improved clamping consistency at the cost of slightly reduced surge headroom, while SMBJ100 trades package compatibility for higher power handling - neither is pin-compatible, and both require validation of mechanical fit and thermal derating.
Availability
SMAJ100 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial SMPS input stages, and on-board DC/DC converter inputs requiring stable component supply, full traceability, and long-lifecycle support.
Supply support for SMAJ100 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, serving automotive, industrial, and consumer markets since 1979.
The SMAJ series is part of TSC's transient voltage suppressor portfolio, engineered specifically for high-reliability, surface-mount overvoltage protection in harsh environments - emphasizing fast response, low leakage, and automotive-grade qualification.
FAQ
What is the maximum clamping voltage of the SMAJ100 under standard test conditions?
The SMAJ100 has a maximum clamping voltage (VC) of 179 V when subjected to a 10/1000 µs waveform with a peak impulse current (IPPM) of 1.7 A. This value is measured at TA = 25 °C and defines the upper voltage limit imposed on protected circuitry during transient events. The SMAJ100 maintains this clamping performance across its specified operating temperature range, making it suitable for applications where downstream components have strict voltage tolerances.
Is the SMAJ100 unidirectional or bidirectional, and how is polarity identified?
The SMAJ100 is a unidirectional TVS diode, meaning it clamps only in reverse bias and conducts forward current like a standard diode. Polarity is identified by a cathode band on the DO-214AC (SMA) package body - the banded end is the cathode and must be connected toward the higher-potential side of the protected line. This configuration ensures proper standoff at 100 V and controlled clamping during overvoltage events. Bidirectional variants use "CA" suffixes (e.g., SMAJ100CA), which SMAJ100 does not carry.
Does the SMAJ100 meet automotive transient immunity standards?
Yes, the SMAJ100 meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling), as confirmed in Taiwan Semiconductor's official documentation. Its 400 W peak pulse power rating, fast <1.0 ps response, and guaranteed clamping behavior under 10/1000 µs waveforms make it appropriate for protecting ECUs, body control modules, and infotainment systems against real-world automotive electrical disturbances.
What is the reverse leakage current specification for the SMAJ100 at its rated working voltage?
The SMAJ100 specifies a maximum reverse leakage current (IR) of 1 µA when biased at its full working stand-off voltage (VWM) of 100 V and tested at TA = 25 °C. This low leakage ensures minimal power loss and avoids false triggering in high-impedance monitoring or sensing circuits. The value remains within specification across the full operating temperature range, supporting reliable performance in battery-powered and energy-efficient designs.
Can the SMAJ100 be used in place of the SMAJ100A, and what is the key functional difference?
The SMAJ100 and SMAJ100A are not interchangeable without design review: SMAJ100 has a VBR range of 111–136 V and clamps at 179 V, while SMAJ100A has a tighter VBR of 111–123 V and clamps at 162 V. The lower clamping voltage of SMAJ100A may improve protection margin in some systems, but its reduced VBR max could increase susceptibility to nuisance conduction near VWM. System-level validation is required before substitution, as SMAJ100 is not a drop-in replacement for SMAJ100A.
SMAJ100 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):
- 100V
- Voltage - Breakdown (Min):
- 111V
- Voltage - Clamping (Max) @ Ipp:
- 179V
- Current - Peak Pulse (10/1000µs):
- 1.7A
- 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)
SMAJ100 FAQ
1.How can I place an order for SMAJ100 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ100 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 SMAJ100 reliable?
The price and inventory of SMAJ100 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ100 is usually 5 days.
3.What payment methods are accepted for SMAJ100?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ100 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ100?
SMAJ100 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ100 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 SMAJ100?
For technical support, including SMAJ100 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ100 requirements.
6.How does Aetrix verify that SMAJ100 is sourced from the original manufacturer or authorized distributors?
All SMAJ100 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 SMAJ100 meets industry standards.
7.What is the process for return or replacement of SMAJ100?
All SMAJ100 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ100, 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 SMAJ100 part is unused and in its original packaging.
Return procedure for SMAJ100:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ100 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 …
