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Taiwan Semiconductor Corporation SMAJ170CH
- Part No.:
- SMAJ170CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ170CH.pdf
- Description:
- TVS DIODE 170VWM 304VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,122
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Product details
Overview
SMAJ170CH from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for automotive-grade overvoltage protection. It features a 170 V working stand-off voltage (VWM), 189–231 V breakdown voltage (VBR) at 1 mA test current, and clamps to ≤304 V at 1.0 A peak impulse current under 10/1000 µs waveform - deployed in on-board DC/DC converters to protect sensitive power management ICs.
For engineers reviewing the SMAJ170CH datasheet, SMAJ170CH pinout, SMAJ170CH application, or SMAJ170CH equivalent, key selection criteria include its AEC-Q101 qualification, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, bidirectional clamping capability, and 400 W peak pulse power rating at 25°C with derating above ambient.
Technical Context
The SMAJ170CH is a unidirectional/bidirectional TVS diode configured as a single die in a glass-passivated junction structure. Its fast response time (<1.0 ps from 0 V to VBR min) enables suppression of ESD and load-dump transients before downstream circuitry sustains damage.
It operates across –55°C to +150°C junction temperature range and meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity requirements. The device exhibits <1.0 µA reverse leakage at VWM = 170 V and maintains clamping performance under non-repetitive 10/1000 µs surge conditions per Fig.5.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 170 V - maximum continuous reverse operating voltage before clamping initiates |
| VBR min / max | 189 V / 231 V at IT = 1 mA - ensures reliable turn-on margin above system rail |
| VC @ IPPM | ≤304 V at IPPM = 1.0 A (10/1000 µs) - defines worst-case voltage seen by protected IC during surge |
| PPPM | 400 W at TA = 25°C (10/1000 µs) - peak energy absorption capacity for transient suppression |
| IR @ VWM | ≤1.0 µA - negligible leakage current preserves efficiency in high-impedance bias networks |
| Package | DO-214AC (SMA) - surface-mount footprint compatible with automated assembly and IPC-7351B land pattern |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band (bidirectional variant SMAJ170CH has no polarity marking; terminals are symmetrical).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bidirectional transient conduction path | Enables clamping of positive and negative polarity surges without orientation dependency |
| Case | Non-electrical mechanical interface | No internal connection; serves only as thermal and mechanical mounting surface |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics use including engine control, body electronics, and ADAS power rails |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Guarantees robustness against real-world vehicle electrical disturbances including load dump and inductive switching |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal cycling and humidity stress |
| Fast response time <1.0 ps | Clamps transients before propagation into sensitive analog or digital circuitry downstream |
| Moisture sensitivity level 1 (J-STD-020) | Eliminates need for dry-pack handling or baking prior to reflow soldering |
Applications
| Automotive On-Board DC/DC Converter | Industrial SMPS Input Stage |
|---|---|
Use Scenario: Protection of 12 V/24 V input stage in automotive buck converter supplying microcontroller and sensor rails. IC Role / Device Role: Bidirectional TVS placed across input terminals to clamp load-dump (Pulse 5a) and coupled noise (Pulse 1/2a). Use Value: Limits transient voltage to ≤304 V, preventing latch-up or gate oxide rupture in upstream MOSFET drivers and PWM controllers. |
Use Scenario: Surge suppression at AC-DC rectifier output feeding isolated flyback controller in factory automation power supply. IC Role / Device Role: Standoff-rated TVS absorbing line-to-line and line-to-ground surges per IEC 61000-4-5. Use Value: Maintains <1.0 µA leakage at 170 V, avoiding unnecessary power loss while delivering 400 W peak pulse handling. |
| LED Driver Module Protection | Telecom Power Interface |
Use Scenario: Input protection for constant-current LED driver used in commercial lighting with long cable runs. IC Role / Device Role: Bidirectional clamping element guarding against induced lightning surges and ESD events on low-voltage DC bus. Use Value: Symmetrical terminal design allows flexible PCB layout without polarity constraints; DO-214AC footprint supports high-density placement. |
Use Scenario: Front-end protection for PoE-powered remote unit receiving 48 V DC over Ethernet cabling. IC Role / Device Role: Primary overvoltage clamp on DC input rail, coordinated with secondary TVS and fuse for staged protection. Use Value: 170 V VWM provides sufficient margin above nominal 48 V/57 V PoE+ rails while enabling fast clamping below 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 SMAJ170AHE3/5A | Unidirectional; VBR = 189–209 V; VC = 275 V @ 1.0 A; same DO-214AC package | Requires correct polarity orientation; lower clamping voltage benefits ultra-low-voltage ICs | Select when unidirectional surge profile dominates and tighter VC margin is critical |
| ON Semiconductor SMAJ170A | Unidirectional; VBR = 189–209 V; VC = 275 V @ 1.0 A; RoHS-compliant, non-halogen | Same polarity constraint; slightly higher IR spec (≤2.0 µA) vs. SMAJ170CH's ≤1.0 µA | Prefer where halogen-free requirement aligns with OEM material declarations |
Compared with SMAJ170CH, the unidirectional alternatives offer lower clamping voltage but require strict polarity-aware layout and lack bidirectional symmetry - making SMAJ170CH preferable for space-constrained, polarity-agnostic placements in automotive and industrial DC rails.
Availability
SMAJ170CH is available at Aetrix Electronics and suitable for automotive power systems, industrial SMPS designs, LED driver modules, and telecom power interfaces requiring stable component supply with AEC-Q101 assurance and ISO 7637-2 compliance.
Supply support for SMAJ170CH 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.
The SMAJ series was developed specifically for high-reliability transient suppression in harsh environments - emphasizing AEC-Q101 qualification, robust glass passivation, and standardized DO-214AC packaging for automated manufacturing.
FAQ
What does the "CH" suffix indicate in SMAJ170CH?
The "CH" suffix in SMAJ170CH denotes a bidirectional configuration with symmetrical clamping behavior in both polarities. Unlike unidirectional variants (e.g., SMAJ170AH), SMAJ170CH has no cathode marking and delivers identical VBR, VC, and IPPM characteristics regardless of voltage polarity - essential for protecting floating or AC-coupled nodes.
Is SMAJ170CH compliant with AEC-Q101 and ISO 7637-2?
Yes, SMAJ170CH is fully AEC-Q101 qualified and certified to meet ISO 7637-2 test pulses 1, 2a, 2b, 3a, and 3b. These qualifications were verified per Taiwan Semiconductor's official qualification report A2102 and confirm suitability for automotive power network protection including 12 V and 24 V systems subject to load dump and inductive switching transients.
What is the maximum clamping voltage of SMAJ170CH under surge conditions?
The maximum clamping voltage (VC) of SMAJ170CH is 304 V when subjected to a 10/1000 µs waveform with a peak impulse current (IPPM) of 1.0 A. This value is specified in the Electrical Specifications table on page 3 of the Taiwan Semiconductor datasheet version A2102 and represents the worst-case voltage imposed on protected circuitry during standardized surge testing.
Does SMAJ170CH require special handling due to moisture sensitivity?
No - SMAJ170CH is rated at Moisture Sensitivity Level 1 per J-STD-020, meaning it can be stored indefinitely at ambient conditions and processed directly through standard reflow soldering profiles without baking or dry-pack requirements. This simplifies manufacturing logistics and eliminates yield risk from moisture-induced popcorning.
How does SMAJ170CH differ from SMAJ170AH in practical design?
SMAJ170CH is bidirectional with symmetrical terminals and no polarity marking, whereas SMAJ170AH is unidirectional with a defined cathode band. SMAJ170CH clamps at ≤304 V, while SMAJ170AH clamps at ≤275 V - a 29 V difference that affects protected IC voltage margins. Layout for SMAJ170CH avoids polarity errors but trades off slightly higher clamping voltage.
SMAJ170CH 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):
- 170V
- Voltage - Breakdown (Min):
- 189V
- Voltage - Clamping (Max) @ Ipp:
- 304V
- Current - Peak Pulse (10/1000µs):
- 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)
SMAJ170CH FAQ
1.How can I place an order for SMAJ170CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ170CH 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 SMAJ170CH reliable?
The price and inventory of SMAJ170CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ170CH is usually 5 days.
3.What payment methods are accepted for SMAJ170CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ170CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ170CH?
SMAJ170CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ170CH 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 SMAJ170CH?
For technical support, including SMAJ170CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ170CH requirements.
6.How does Aetrix verify that SMAJ170CH is sourced from the original manufacturer or authorized distributors?
All SMAJ170CH 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 SMAJ170CH meets industry standards.
7.What is the process for return or replacement of SMAJ170CH?
All SMAJ170CH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ170CH, 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 SMAJ170CH part is unused and in its original packaging.
Return procedure for SMAJ170CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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