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Taiwan Semiconductor Corporation SMAJ170C
- Part No.:
- SMAJ170C
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ170C.pdf
- Description:
- 300W, 210V, 10%, BIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:9,230
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Product details
Overview
SMAJ170C from Taiwan Semiconductor is a bidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast-rising ESD and surge transients. It features a 170 V working stand-off voltage (VWM), 189–231 V breakdown voltage (VBR @ 1 mA), 304 V maximum clamping voltage (VC @ 1 A), 400 W peak pulse power (10/1000 µs), and operates across –55 °C to +150 °C junction temperature range - deployed in automotive DC/DC converters and industrial power supplies.
For engineers reviewing the SMAJ170C datasheet, SMAJ170C pinout, SMAJ170C application, or SMAJ170C equivalent, key selection criteria include bidirectional clamping capability, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, low leakage (<1 µA at VWM), sub-1 ps response time, and DO-214AC mechanical compatibility with automated SMT placement.
Technical Context
The SMAJ170C implements a glass-passivated silicon avalanche junction optimized for unidirectional or bidirectional transient suppression. Its electrical behavior follows standardized TVS diode characteristics: sharp reverse breakdown onset, low dynamic impedance during clamping, and minimal capacitance (typically <100 pF at 1 MHz, zero bias).
It is rated for non-repetitive 10/1000 µs waveform surges up to 400 W (derated above 25 °C), supports 40 A peak forward surge current (8.3 ms half-sine), and maintains stable clamping performance under transient conditions per IEC 61000-4-2/4-4/4-5 and ISO 7637-2 requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 170 V - Maximum continuous reverse operating voltage before conduction begins; defines system bus voltage margin. |
| VBR min/max | 189–231 V @ 1 mA - Confirmed breakdown threshold range ensures reliable turn-on during overvoltage events. |
| VC @ IPPM | 304 V @ 1 A - Clamping voltage limits downstream IC stress during 10/1000 µs surge; critical for 24/48 V rail protection. |
| PPPM | 400 W (10/1000 µs) - Peak pulse power rating determines survivability against automotive load-dump or inductive switching transients. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage preserves efficiency in high-impedance sensing or battery-backed circuits. |
| TJ max | +150 °C - Enables operation in under-hood automotive environments and thermally constrained industrial enclosures. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with cathode band marking; compatible with J-STD-002 soldering. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band; moisture sensitivity level 1 (J-STD-020), UL 94V-0 rated compound, weight ≈0.060 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Current entry point in forward bias; reverse-biased terminal during clamping | Connected to protected line (e.g., 170 V DC bus); forms bidirectional clamp path with cathode. |
| Cathode (banded end) | Current exit point in forward bias; primary clamping node in reverse bias | Typically tied to ground or low-impedance return; establishes reference for symmetric clamping in bidirectional mode. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating rails without polarity constraints - verified for SMAJ170C per datasheet Table "Devices for Bipolar Applications". |
| Sub-1 ps response time | Ensures clamping activation before ESD or fast transients damage sensitive inputs - specified as "typically less than 1.0 ps from 0 V to VBR min". |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (line impedance coupling) - critical for automotive ECUs and body control modules. |
| Glass passivated junction | Improves long-term reliability and stability of breakdown voltage under thermal cycling and humidity exposure - confirmed in "FEATURES" section. |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - required for export to EU, China, and Japan markets. |
Applications
| Automotive Body Control Module (BCM) | Industrial 48 V DC/DC Converter |
|---|---|
Use Scenario: Protects LIN bus transceivers and microcontroller I/O from load-dump spikes and battery reversal transients in vehicle door modules. IC Role / Device Role / Timing Role: Bidirectional TVS diode placed between LIN line and chassis ground to clamp ±100 V transients within 1 ns. Use Value: Prevents latch-up or permanent damage to 5 V tolerant transceivers while maintaining signal integrity below 100 pF capacitance. |
Use Scenario: Shields isolated gate drivers and feedback optocouplers in telecom-grade 48 V input DC/DC converters against surge coupling from adjacent power stages. IC Role / Device Role / Timing Role: Primary clamping device on secondary-side 12 V bias rail, triggered by 10/1000 µs surges exceeding 170 V standoff. Use Value: Limits transient overshoot to ≤304 V, ensuring MOSFET gate oxide and opto-LED remain within safe operating area. |
| Smart Lighting Driver (Dali/0–10 V) | Programmable Logic Controller (PLC) I/O Terminal |
Use Scenario: Guards analog dimming inputs and DALI communication lines in outdoor LED streetlight controllers exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Bidirectional TVS connected across differential DALI pair (DATA+ / DATA−) referenced to local ground. Use Value: Maintains <1 µA leakage at 170 V standby, eliminating false triggering while surviving 400 W 10/1000 µs pulses. |
Use Scenario: Protects 24 V digital input terminals in industrial PLC backplanes from field-wiring induced transients and relay coil flyback. IC Role / Device Role / Timing Role: Standoff-rated TVS placed between input line and common, activated only during >189 V excursions. Use Value: Enables robust operation in harsh factory environments with repeated 40 A surge tolerance (8.3 ms half-sine) and –55 °C cold-start capability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ170A | Narrower VBR range (189–209 V); tighter tolerance; same VWM, VC, and PPPM. | Preferred where tighter breakdown consistency is required for precision clamping thresholds. | Select SMAJ170A when VBR matching across production lots is critical; SMAJ170C offers broader tolerance for cost-sensitive volume designs. |
| SMBJ170C | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; higher PPPM = 600 W. | Suitable for higher-energy surge environments where PCB space allows larger footprint. | Choose SMBJ170C if system-level testing requires >400 W surge margin; SMAJ170C fits tighter layouts with proven 400 W capability. |
Compared with SMAJ170A and SMBJ170C, the SMAJ170C balances cost-effective DO-214AC packaging, industry-standard 400 W surge rating, and bidirectional clamping - making it optimal for space-constrained automotive and industrial applications where precise VBR tolerance is secondary to footprint and qualification compliance.
Availability
SMAJ170C is available at Aetrix Electronics and suitable for automotive body electronics, industrial DC/DC converters, and smart lighting systems requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMAJ170C 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 - headquartered in Hsinchu Science Park, Taiwan.
The SMAJ series was developed specifically for high-reliability transient suppression in automotive and industrial power systems, emphasizing ISO 7637-2 compliance, low leakage, and automated assembly compatibility.
FAQ
What does the 'C' suffix indicate in SMAJ170C?
The 'C' suffix in SMAJ170C denotes bidirectional configuration - meaning the device provides symmetrical clamping in both polarities, unlike unidirectional variants (e.g., SMAJ170). This is explicitly confirmed in the datasheet's "Devices for Bipolar Applications" section and enables use on floating or AC-coupled lines without polarity concerns.
Is SMAJ170C compliant with ISO 7637-2 for automotive applications?
Yes, SMAJ170C meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements as stated in the "FEATURES" list. Its 400 W peak pulse power rating (10/1000 µs), low clamping voltage (304 V), and fast response time ensure robust protection against load-dump and switching transients in 12 V and 24 V automotive networks.
What is the maximum clamping voltage of SMAJ170C and at what test condition?
The maximum clamping voltage of SMAJ170C is 304 V, measured at a peak impulse current (IPPM) of 1 A with a 10/1000 µs waveform - per the Electrical Specifications table on page 3 of the U2102 datasheet. This value defines the upper voltage limit imposed on protected circuitry during surge events.
Does SMAJ170C require derating at elevated ambient temperatures?
Yes, SMAJ170C must be derated above TA = 25 °C per Figure 2 ("Pulse Derating Curve") in the datasheet. At 85 °C ambient, its 400 W peak pulse power drops to approximately 260 W; at 125 °C, it falls to ~140 W - critical for under-hood or enclosed industrial deployments.
Can SMAJ170C be used in place of SMAJ170A?
SMAJ170C and SMAJ170A share identical VWM (170 V), VC (304 V), and PPPM (400 W), but differ in VBR tolerance: SMAJ170C has 189–231 V vs. SMAJ170A's tighter 189–209 V. Substitution is electrically viable where broader breakdown spread is acceptable; however, design validation should confirm system-level clamping margin remains sufficient.
SMAJ170C 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ170C FAQ
1.How can I place an order for SMAJ170C through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ170C 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 SMAJ170C reliable?
The price and inventory of SMAJ170C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ170C is usually 5 days.
3.What payment methods are accepted for SMAJ170C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ170C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ170C?
SMAJ170C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ170C 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 SMAJ170C?
For technical support, including SMAJ170C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ170C requirements.
6.How does Aetrix verify that SMAJ170C is sourced from the original manufacturer or authorized distributors?
All SMAJ170C 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 SMAJ170C meets industry standards.
7.What is the process for return or replacement of SMAJ170C?
All SMAJ170C units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ170C, 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 SMAJ170C part is unused and in its original packaging.
Return procedure for SMAJ170C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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