My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ17CH
- Part No.:
- SMAJ17CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ17CH.pdf
- Description:
- TVS DIODE 17VWM 30.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,183
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ17CH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 17V working stand-off voltage (VWM), 18.9–23.1V breakdown voltage (VBR) at 1mA test current, and clamps to ≤30.5V at 13.1A peak pulse current under 10/1000μs waveform - ideal for protecting automotive-grade DC/DC converters against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMAJ17CH datasheet, SMAJ17CH pinout, SMAJ17CH application, or SMAJ17CH equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, clamping performance data, moisture sensitivity level (MSL 1), and direct alternatives with documented voltage and power differences - all critical for automotive ECU, lighting module, and industrial SMPS design validation.
Technical Context
The SMAJ17CH employs a glass-passivated silicon junction optimized for fast transient response (<1.0ps rise time from 0V to VBR min) and low leakage (<1μA at 17V). Its unidirectional configuration provides asymmetric protection with defined cathode polarity, enabling integration into positive-rail surge suppression paths without reverse conduction concerns.
It meets ISO 7637-2 immunity requirements for automotive electronics and operates across –55°C to +150°C junction temperature range. The device delivers 400W peak pulse power (10/1000μs) at 25°C, derating linearly above ambient per published curve (Fig.2), with steady-state power dissipation rated at 1W.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 17 V - maximum continuous reverse operating voltage before clamping begins; sets safe DC rail margin for 12V automotive systems. |
| VBR @ IT=1mA | 18.9–23.1 V - guaranteed breakdown threshold; ensures reliable turn-on during transients exceeding nominal supply. |
| VC @ IPPM | ≤30.5 V at 13.1 A - clamping voltage under 10/1000μs surge; limits downstream IC stress during load dump events. |
| PPPM | 400 W (10/1000μs) - peak surge energy handling capacity; supports high-energy transients per ISO 7637-2 Pulse 5a. |
| IR @ VWM | ≤1 μA - ultra-low reverse leakage at stand-off voltage; preserves battery life in always-on vehicle modules. |
| TJ max | +150 °C - extended thermal rating enables placement near heat sources in engine control units. |
| Package | DO-214AC (SMA) - industry-standard surface-mount outline with 0.060g mass; compatible with automated reflow assembly. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈0.060g. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal in forward bias; connected to protected line in unidirectional clamp configuration. | Accepts surge current during reverse transient; must be tied to system ground via low-inductance path for effective clamping. |
| Cathode | Negative terminal; marked by band on package body. | Connected to protected DC rail (e.g., +12V); defines directionality - blocks forward current, conducts reverse surge to ground. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood applications including temperature cycling, mechanical shock, and humidity exposure per JEDEC standard. |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal stress and humidity. |
| Fast response time | Typically <1.0 ps from 0 V to VBR min - faster than most microcontroller I/O protection needs, preventing latch-up before clamping. |
| ISO 7637-2 compliance | Tested against Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling) - full automotive EMC readiness. |
| MSL Level 1 | No floor life limitation; suitable for standard SMT reflow without baking - reduces manufacturing overhead. |
Applications
| Automotive Engine Control Unit (ECU) | LED Headlamp Driver Module |
|---|---|
Use Scenario: Protection of 12V input rail against load dump and alternator ripple in gasoline/diesel ECUs. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery feed and LDO/regulator input to clamp transients before they reach sensitive MCU and sensor interfaces. Use Value: Clamps 13.1A surges to ≤30.5V, keeping downstream 3.3V/5V regulators within safe SOA and avoiding reset or damage during ISO 7637-2 Pulse 5a events. |
Use Scenario: Surge suppression on constant-current LED driver input in adaptive front-lighting systems (AFS). IC Role / Device Role / Timing Role: Primary overvoltage guard on DC input stage, absorbing switching noise from buck controller and external ESD events. Use Value: Low 1μA leakage at 17V prevents standby current drain; 400W rating handles repetitive PWM-induced spikes without degradation. |
| Industrial On-Board DC/DC Converter | Smart Home Power Adapter |
Use Scenario: Input-side protection for isolated 24V-to-5V flyback converters in factory automation I/O modules. IC Role / Device Role / Timing Role: Fast-acting shunt element that diverts surge energy to chassis ground during field-wiring faults or lightning-induced coupling. Use Value: 18.9–23.1V VBR ensures no false triggering during normal 24V ±10% operation while responding within picoseconds to >30V transients. |
Use Scenario: Secondary-side transient suppression on 5V USB-C PD output rails in compact wall adapters. IC Role / Device Role / Timing Role: Final-stage clamp after secondary rectification, safeguarding connected devices from output overvoltage due to feedback loop failure. Use Value: DO-214AC footprint allows high-density layout; MSL Level 1 eliminates pre-bake steps, accelerating production ramp for consumer OEMs. |
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 SMAJ17A | Lower VBR range (18.9–20.9V); tighter tolerance but reduced margin above VWM. | Same 400W rating and DO-214AC package; slightly lower clamping voltage (27.6V vs. 30.5V) improves downstream protection headroom. | Select when tighter VBR consistency is required and lower VC is prioritized over higher surge margin. |
| ON Semiconductor SMAJ17CA | Bidirectional variant (CH suffix = unidirectional; CA = bidirectional); same VWM/VBR specs but symmetrical clamping in both polarities. | Required only where AC-coupled or dual-polarity signal lines need protection; adds unnecessary cost and complexity for DC rail use. | Choose only for bidirectional signal paths (e.g., CAN bus stubs); avoid for standard 12V/24V DC power rails. |
Compared with SMAJ17CH, SMAJ17A offers tighter VBR control and lower clamping for enhanced safety margin, while SMAJ17CA introduces bidirectional capability irrelevant to unidirectional power rail protection - making SMAJ17CH the optimal balance of precision, cost, and application-specific functionality.
Availability
SMAJ17CH is available at Aetrix Electronics and suitable for automotive ECU designs, LED lighting modules, and industrial DC/DC converters requiring stable component supply with AEC-Q101 qualification and ISO 7637-2 compliance.
Supply support for SMAJ17CH 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 global automotive, industrial, and consumer markets since 1979.
The SMAJ series was developed specifically for AEC-Q101-compliant transient protection in harsh automotive environments, emphasizing reliability under thermal cycling, high surge energy, and long-term parametric stability.
FAQ
What is the polarity configuration of SMAJ17CH?
SMAJ17CH is a unidirectional TVS diode with cathode-marked polarity. The cathode band indicates the terminal to be connected to the protected DC rail (e.g., +12V), while the anode connects to ground. This configuration blocks forward current and conducts reverse surge energy to ground - essential for single-polarity power rail protection. SMAJ17CH does not conduct in forward bias beyond its low VF (~3.5V at 25A), distinguishing it from bidirectional variants like SMAJ17CA.
Does SMAJ17CH meet automotive qualification standards?
Yes, SMAJ17CH is AEC-Q101 qualified and tested per ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b waveforms. It operates across –55°C to +150°C junction temperature and passes JESD201 Class 2 whisker testing and J-STD-020 MSL Level 1 - confirming suitability for under-hood automotive applications including engine control units and lighting modules where reliability under thermal and mechanical stress is critical. SMAJ17CH's qualification documentation is available directly from Taiwan Semiconductor.
What is the clamping voltage of SMAJ17CH at rated surge current?
SMAJ17CH clamps to a maximum of 30.5V at 13.1A peak pulse current under the standardized 10/1000μs waveform. This value is measured at TA = 25°C and represents the upper limit of voltage seen by downstream circuitry during a worst-case transient. The clamping voltage remains stable across temperature due to the device's glass-passivated junction, ensuring consistent protection behavior in automotive and industrial environments where ambient temperatures vary widely. SMAJ17CH's VC specification is validated per Fig.5 waveform definition in the official datasheet.
How does SMAJ17CH differ from SMAJ17AH?
SMAJ17CH has a VBR range of 18.9–23.1V at 1mA, while SMAJ17AH specifies 18.9–20.9V - a tighter upper bound reflecting improved process control. Both share identical VWM (17V), IR (≤1μA), package (DO-214AC), and PPPM (400W), but SMAJ17AH's narrower VBR improves predictability in precision clamp designs. SMAJ17CH remains preferred where broader surge margin is acceptable and cost sensitivity is higher. Neither part is pin-compatible with bidirectional variants like SMAJ17CA, as polarity and internal structure differ.
Is SMAJ17CH suitable for use in RoHS-compliant and halogen-free assemblies?
Yes, SMAJ17CH is RoHS compliant and halogen-free per IEC 61249-2-21. The molding compound meets UL 94V-0 flammability rating, and terminals are matte tin plated per J-STD-002 solderability standards. These attributes make SMAJ17CH appropriate for environmentally regulated markets including EU automotive supply chains and consumer electronics requiring full material declarations. Taiwan Semiconductor certifies SMAJ17CH's compliance status in its official product change notifications and material content reports.
SMAJ17CH 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):
- 17V
- Voltage - Breakdown (Min):
- 18.9V
- Voltage - Clamping (Max) @ Ipp:
- 30.5V
- Current - Peak Pulse (10/1000µs):
- 13.1A
- 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)
SMAJ17CH FAQ
1.How can I place an order for SMAJ17CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ17CH 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 SMAJ17CH reliable?
The price and inventory of SMAJ17CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ17CH is usually 5 days.
3.What payment methods are accepted for SMAJ17CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ17CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ17CH?
SMAJ17CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ17CH 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 SMAJ17CH?
For technical support, including SMAJ17CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ17CH requirements.
6.How does Aetrix verify that SMAJ17CH is sourced from the original manufacturer or authorized distributors?
All SMAJ17CH 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 SMAJ17CH meets industry standards.
7.What is the process for return or replacement of SMAJ17CH?
All SMAJ17CH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ17CH, 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 SMAJ17CH part is unused and in its original packaging.
Return procedure for SMAJ17CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ17CH 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…
