My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ20H
- Part No.:
- SMAJ20H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ20H.pdf
- Description:
- TVS DIODE 20VWM 35.8VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,208
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ20H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 20 V working stand-off voltage (VWM), 22.2–27.1 V breakdown voltage (VBR), 35.8 V maximum clamping voltage (VC) at 11.2 A peak pulse current, and 400 W peak pulse power rating per 10/1000 µs waveform - deployed in automotive-grade SMPS and on-board DC/DC converters.
For engineers reviewing the SMAJ20H datasheet, SMAJ20H pinout, SMAJ20H application, or SMAJ20H equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b transients, AEC-Q101 qualification status, DO-214AC (SMA) package thermal and mechanical compatibility, and unidirectional polarity marking for correct PCB orientation.
Technical Context
The SMAJ20H operates as a unidirectional avalanche diode with glass-passivated junction, enabling sub-1 ps response time from 0 V to VBR(min). Its clamping behavior is defined by a single-die silicon structure optimized for fast energy diversion during ESD and load-dump events.
It meets ISO 7637-2 immunity requirements for automotive electronics and supports steady-state power dissipation up to 1 W at 25 °C, with derating above ambient temperature per Fig.2. Junction temperature range spans −55 °C to +150 °C, aligning with under-hood and engine-control module environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before leakage exceeds 1 µA; sets upper limit for protected circuit's nominal rail. |
| VBR @ IT = 1 mA | 22.2–27.1 V - Breakdown threshold range defining reliable avalanche initiation; ensures consistent turn-on across production lots. |
| VC @ IPPM = 11.2 A | 35.8 V - Maximum clamped voltage during 10/1000 µs surge; determines worst-case overvoltage seen by downstream ICs. |
| PPPM | 400 W - Peak pulse power handling per standard 10/1000 µs waveform; validates robustness against ISO 7637-2 Pulse 5a (load dump). |
| IR @ VWM | <1 µA - Reverse leakage at rated stand-off voltage; minimizes quiescent power loss in battery-powered systems. |
| TJ(max) | +150 °C - Maximum junction temperature; enables operation in high-ambient automotive and industrial power supply environments. |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single-ended cathode-banded configuration. Matte tin-plated leads meet J-STD-002 solderability; moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-potential node; defines current path during reverse-biased clamping event. |
| Cathode (banded end) | High-side transient input terminal | Connected to protected line (e.g., 24 V rail); avalanche conduction occurs when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronic modules requiring reliability under temperature cycling, humidity, and mechanical shock per JESD22 standards. |
| Clamping voltage ≤35.8 V at 11.2 A | Ensures downstream 3.3 V/5 V logic and microcontrollers remain within absolute maximum ratings during 10/1000 µs surges. |
| Response time <1.0 ps | Enables suppression of fast-rising ESD transients (IEC 61000-4-2) before sensitive circuitry sustains damage. |
| Meets ISO 7637-2 Pulse 1/2a/2b/3a/3b | Provides system-level immunity certification for automotive infotainment, body control, and ADAS power inputs without external filtering. |
| DO-214AC (SMA) package | Standardized footprint compatible with automated SMT placement; 0.060 g mass supports reflow profile stability and board-level reliability. |
Applications
| Automotive Body Control Module (BCM) | Industrial DC/DC Converter Input Stage |
|---|---|
Use Scenario: Protects 12 V/24 V power input of BCM from load-dump transients (ISO 7637-2 Pulse 5a) and coupled alternator noise. IC Role / Device Role / Timing Role: Unidirectional TVS placed between fused battery rail and primary DC/DC converter input. Use Value: Limits clamped voltage to 35.8 V, preventing damage to upstream fuse box monitoring ICs and downstream buck controller ICs rated for 40 V max. |
Use Scenario: Shields isolated 48 V-to-12 V DC/DC converter input from switching noise and field-induced surges in factory automation equipment. IC Role / Device Role / Timing Role: Standoff-rated TVS mounted directly at converter input terminals to absorb repetitive 10/1000 µs pulses. Use Value: 400 W peak power rating sustains >100,000 surge cycles without degradation, supporting 10-year industrial product lifecycle. |
| LED Driver Power Supply | USB-C PD Adapter Secondary Side |
Use Scenario: Guards constant-current LED driver ICs against voltage spikes induced by inductive load switching in streetlight and signage applications. IC Role / Device Role / Timing Role: Unidirectional TVS connected across output capacitor to clamp flyback overshoot during MOSFET turn-off. Use Value: Sub-1 ps response captures nanosecond-scale ringing, reducing need for snubber networks and lowering BOM cost. |
Use Scenario: Secures secondary-side 20 V output rail of USB-C PD adapter against reverse-polarity misconnection and hot-plug transients. IC Role / Device Role / Timing Role: Standoff-matched TVS (VWM = 20 V) placed between VBUS and GND after secondary rectification. Use Value: 1 µA leakage at 20 V preserves no-load efficiency targets (<0.1 W) required for Energy Star Level VI compliance. |
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 SMAJ20A | Lower VBR range (22.2–24.5 V); tighter tolerance but reduced margin above VWM. | Preferred where tighter clamping consistency is needed at lower surge currents (≤8 A). | Select SMAJ20A if design requires <±10% VBR variation and operates below 300 W peak pulse stress. |
| ON Semiconductor SMAJ20CA | Bidirectional variant (VRWM = 20 V, symmetrical clamping); higher capacitance (~100 pF vs. ~50 pF). | Suitable for AC-coupled data lines or dual-polarity rails where reverse polarity events must also be suppressed. | Choose SMAJ20CA only when bidirectional protection is mandatory; otherwise SMAJ20H offers lower capacitance and better DC rail efficiency. |
Compared with Littelfuse SMAJ20A and ON Semi SMAJ20CA, the SMAJ20H provides optimal balance of clamping margin (VC − VWM = 15.8 V), ultra-low leakage, and AEC-Q101 validation - making it the preferred choice for unidirectional 20 V automotive and industrial DC power protection where layout space and thermal budget are constrained.
Availability
SMAJ20H is available at Aetrix Electronics and suitable for automotive body control modules, industrial DC/DC converters, LED driver power supplies, and USB-C PD adapter secondary-side protection requiring stable component supply across multi-year production cycles.
Supply support for SMAJ20H 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, and power MOSFETs for automotive and industrial markets.
The SMAJ series was developed specifically for AEC-Q101-compliant transient suppression in harsh-environment automotive electronics, emphasizing high-reliability packaging, precise clamping control, and ISO 7637-2 system-level immunity.
FAQ
What is the maximum clamping voltage of the SMAJ20H under standard test conditions?
The SMAJ20H exhibits a maximum clamping voltage (VC) of 35.8 V when subjected to an 11.2 A peak pulse current with a 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees that protected downstream components experience no more than 35.8 V during transient events - critical for safeguarding 3.3 V and 5 V logic interfaces connected to the same rail as the SMAJ20H.
Is the SMAJ20H suitable for automotive applications requiring AEC-Q101 qualification?
Yes, the SMAJ20H is explicitly AEC-Q101 qualified per the manufacturer's documentation. It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias, and mechanical shock - validating its suitability for under-hood and chassis-mounted automotive modules such as body control units, lighting drivers, and infotainment power supplies where the SMAJ20H serves as primary overvoltage protection.
How does the SMAJ20H differ from the SMAJ20AH variant?
The SMAJ20AH has a tighter breakdown voltage range (22.2–24.5 V) versus SMAJ20H (22.2–27.1 V), resulting in lower typical clamping voltage (32.4 V vs. 35.8 V) but reduced margin above VWM. Both share identical package, power rating, and AEC-Q101 qualification. The SMAJ20H is preferred when design裕度 (margin) against VBR variation is prioritized; SMAJ20AH suits applications demanding tighter clamping consistency at moderate surge levels.
What is the reverse leakage current specification for the SMAJ20H at its working stand-off voltage?
The SMAJ20H specifies a maximum reverse leakage current (IR) of 1 µA at its 20 V working stand-off voltage (VWM). This ultra-low leakage ensures minimal power loss in always-on automotive subsystems and extends battery life in portable industrial tools where the SMAJ20H guards auxiliary 20 V rails - a key differentiator versus legacy TVS devices with >5 µA leakage.
Does the SMAJ20H meet ISO 7637-2 immunity requirements for automotive electronics?
Yes, the SMAJ20H is validated to meet ISO 7637-2 Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling) test profiles. Its 400 W peak pulse power rating and sub-1 ps response enable direct integration into automotive power distribution networks without supplemental RC filters - a capability confirmed in Taiwan Semiconductor's application notes for BCM and ADAS power rail protection using the SMAJ20H.
SMAJ20H 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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 35.8V
- Current - Peak Pulse (10/1000µs):
- 11.2A
- 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)
SMAJ20H FAQ
1.How can I place an order for SMAJ20H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ20H 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 SMAJ20H reliable?
The price and inventory of SMAJ20H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ20H is usually 5 days.
3.What payment methods are accepted for SMAJ20H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ20H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ20H?
SMAJ20H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ20H 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 SMAJ20H?
For technical support, including SMAJ20H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ20H requirements.
6.How does Aetrix verify that SMAJ20H is sourced from the original manufacturer or authorized distributors?
All SMAJ20H 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 SMAJ20H meets industry standards.
7.What is the process for return or replacement of SMAJ20H?
All SMAJ20H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ20H, 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 SMAJ20H part is unused and in its original packaging.
Return procedure for SMAJ20H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ20H 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 …
