My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ30CH
- Part No.:
- SMAJ30CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ30CH.pdf
- Description:
- TVS DIODE 30VWM 53.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,451
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ30CH from Taiwan Semiconductor is a unidirectional 30V stand-off transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, rated for 400W peak pulse power (10/1000μs), 53.5V clamping voltage at 7.5A peak impulse current, and AEC-Q101 qualified for automotive-grade reliability. It protects DC/DC converters and SMPS inputs against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMAJ30CH datasheet, SMAJ30CH pinout, SMAJ30CH application, or SMAJ30CH equivalent, key selection criteria include its 30V working voltage, 33.3–40.7V breakdown range at 1mA, sub-1ps response time, <1μA leakage above 10V, and bidirectional-capable CH-suffix marking indicating unidirectional polarity with cathode band.
Technical Context
The SMAJ30CH employs a glass-passivated silicon junction optimized for fast transient suppression in automotive and industrial power rails. Its clamping behavior is defined by a 10/1000μs waveform, with thermal derating above 25°C per Fig.2 and maximum junction temperature of 150°C.
It meets ISO 7637-2 immunity requirements for vehicle electrical systems and supports automated SMT placement with J-STD-002 solderability and JESD201 Class 2 whisker resistance. Polarity is marked by a cathode band; moisture sensitivity level is J-STD-020 Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 30 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR @ IT=1mA | 33.3–40.7 V - Breakdown voltage range confirming reliable turn-on margin above VWM |
| VC @ IPPM=7.5A | 53.5 V - Clamped voltage during 10/1000μs surge, limiting downstream IC stress |
| PPPM | 400 W - Peak pulse power handling capability under standard 10/1000μs waveform |
| IR @ VWM | <1 μA - Ultra-low leakage ensuring minimal standby power loss in high-impedance circuits |
| Response Time | <1.0 ps - Sub-picosecond junction response enabling effective suppression of ESD and fast transients |
| TJ max | 150 °C - Maximum junction temperature supporting operation in under-hood automotive environments |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single-diode configuration with cathode band marking polarity. Case meets UL 94V-0 flammability rating; matte tin-plated leads ensure solderability per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side (non-banded end) | Connected to protected line; conducts during reverse transient when cathode is held higher |
| Cathode | Ground/Reference side (banded end) | Connected to system ground or low-impedance return; defines unidirectional clamping direction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive electronics per stress test requirements including HTOL, TCT, and ESD |
| Glass passivated junction | Enhances long-term reliability and stability of breakdown voltage under thermal cycling |
| ISO 7637-2 compliance | Guarantees robustness against real-world automotive load-dump and inductive-switching transients |
| Moisture sensitivity Level 1 | Enables unlimited floor life and eliminates bake requirements prior to reflow |
| Halogen-free & RoHS compliant | Meets IEC 61249-2-21 and EU RoHS directives for environmentally constrained applications |
Applications
| Automotive Infotainment Power Rail | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protects 12V supply input of head-unit MCU and audio codec from battery line transients during load dump or jump-start events. IC Role / Device Role / Timing Role: Unidirectional TVS clamping device placed at board edge before LDO regulator input. Use Value: Limits voltage to ≤53.5V during 400W ISO 7637-2 Pulse 5a, preventing latch-up or overvoltage damage to 3.3V/5V logic. |
Use Scenario: Shields 24V digital input channel of programmable logic controller against field-wiring induced surges and relay coil flyback. IC Role / Device Role / Timing Role: Primary transient suppressor on DIN-rail mounted I/O module front-end, upstream of optocoupler isolation. Use Value: Withstands ≥7.5A 10/1000μs impulses while maintaining <1μA leakage, preserving signal integrity in high-impedance sensing paths. |
| On-Board DC/DC Converter Input | LED Driver Supply Protection |
Use Scenario: Secures input of 48V-to-12V buck converter in electric vehicle auxiliary systems against alternator ripple and switching noise coupling. IC Role / Device Role / Timing Role: Fast-response clamping diode placed directly across converter input capacitors. Use Value: Sub-1ps response ensures clamping initiates before MOSFET gate oxide breakdown thresholds are exceeded during fast-edge transients. |
Use Scenario: Guards constant-current LED driver IC supply pins in streetlight modules exposed to lightning-induced surges on AC mains feeders. IC Role / Device Role / Timing Role: Standoff-rated TVS on secondary-side 24V rail, coordinated with MOV on primary side. Use Value: 30V VWM provides sufficient margin above nominal 24V rail while 53.5V VC stays below driver IC absolute maximum ratings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ30AHE3/5A | Same DO-214AC package, 30V VWM, but lower clamping voltage (48.4V @ 8.3A) and tighter VBR tolerance (33.3–36.8V) | Better suited for designs requiring lower clamping headroom; slightly higher IPPM rating | Select when lower VC is critical and tighter VBR distribution improves yield in high-volume production |
| ON Semiconductor SMAJ30A | Identical electrical specs and DO-214AC footprint, but not AEC-Q101 qualified; RoHS-compliant only | Acceptable for industrial/commercial use where automotive qualification is not mandated | Choose for cost-sensitive non-automotive designs where full AEC-Q101 validation is unnecessary |
Compared with SMAJ30CH, the Littelfuse SMAJ30AHE3/5A offers lower clamping voltage at higher peak current, while the ON Semiconductor SMAJ30A matches performance without automotive qualification-enabling trade-offs between reliability assurance, clamping precision, and cost.
Availability
SMAJ30CH is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLCs, and on-board DC/DC converters requiring stable component supply with AEC-Q101 traceability and consistent DO-214AC packaging.
Supply support for SMAJ30CH 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 devices since 1979.
The SMAJ series was developed specifically for automotive and industrial transient protection, emphasizing AEC-Q101 compliance, ISO 7637-2 immunity, and robust SMT manufacturability in the DO-214AC package.
FAQ
What is the polarity configuration of SMAJ30CH?
The SMAJ30CH is a unidirectional TVS diode with cathode indicated by a band on the DO-214AC package. When reverse biased (cathode positive relative to anode), it clamps transients above its breakdown voltage; forward conduction occurs at ~3.5V. This polarity must be observed during PCB layout to ensure correct protection direction on the protected line.
Does SMAJ30CH meet automotive qualification standards?
Yes, SMAJ30CH is AEC-Q101 qualified, having passed stress tests including high-temperature operating life (HTOL), temperature cycling (TCT), and electrostatic discharge (HBM/MM). It also complies with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electrical system immunity, making it suitable for under-hood and infotainment applications.
What is the maximum clamping voltage of SMAJ30CH under surge conditions?
The SMAJ30CH has a maximum clamping voltage (VC) of 53.5 V at 7.5 A peak pulse current (IPPM) using the standard 10/1000μs waveform. This value is guaranteed across temperature and represents the upper limit of voltage seen by downstream circuitry during a worst-case transient event.
Can SMAJ30CH be used in bidirectional configurations?
No-SMAJ30CH is unidirectional. For bidirectional protection, Taiwan Semiconductor specifies the SMAJ30AH variant (marked CK), which uses symmetrical breakdown characteristics in both directions. The "CH" suffix explicitly denotes unidirectional construction with cathode band marking.
What is the thermal derating behavior of SMAJ30CH above 25°C ambient?
SMAJ30CH's peak pulse power rating derates linearly above 25°C ambient, per Figure 2 in the datasheet. At 85°C, its 400W rating reduces to approximately 240W; at 125°C, it falls to ~120W. Designers must apply this derating curve when sizing for high-temperature environments like engine compartments.
SMAJ30CH 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:
- -
- Bidirectional Channels:
- 1
- 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)
SMAJ30CH FAQ
1.How can I place an order for SMAJ30CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ30CH 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 SMAJ30CH reliable?
The price and inventory of SMAJ30CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ30CH is usually 5 days.
3.What payment methods are accepted for SMAJ30CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ30CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ30CH?
SMAJ30CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ30CH 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 SMAJ30CH?
For technical support, including SMAJ30CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ30CH requirements.
6.How does Aetrix verify that SMAJ30CH is sourced from the original manufacturer or authorized distributors?
All SMAJ30CH 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 SMAJ30CH meets industry standards.
7.What is the process for return or replacement of SMAJ30CH?
All SMAJ30CH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ30CH, 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 SMAJ30CH part is unused and in its original packaging.
Return procedure for SMAJ30CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ30CH 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
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 …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
