My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ170AH
- Part No.:
- SMAJ170AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ170AH.pdf
- Description:
- TVS DIODE 170VWM 275VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,596
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ170AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in DC power rails. It features a 170 V working stand-off voltage (VWM), 189–209 V breakdown voltage (VBR), 275 V maximum clamping voltage (VC) at 1.1 A peak impulse current, and 400 W peak pulse power rating per 10/1000 µs waveform - suitable for automotive-grade DC/DC converters subject to ISO 7637-2 transients.
For engineers reviewing the SMAJ170AH datasheet, SMAJ170AH pinout, SMAJ170AH application, or SMAJ170AH equivalent, this device is evaluated for high-reliability surge suppression in 12 V–48 V industrial and automotive power systems where low leakage (<1.1 µA at 170 V), fast response (<1.0 ps), and AEC-Q101 qualification are critical selection criteria.
Technical Context
The SMAJ170AH operates as a unidirectional avalanche diode with glass-passivated junction, optimized for clamping transient energy without latch-up. Its electrical behavior follows standardized TVS parameters defined under IEC 61000-4-5 and ISO 7637-2 Pulse 1/2a/2b/3a/3b waveforms, with thermal derating above 25 °C per Fig.2 and non-repetitive pulse handling up to 150 °C junction temperature.
It uses a single-die DO-214AC (SMA) package with cathode band polarity marking, matte tin-plated leads compliant with J-STD-002 solderability, and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements - enabling automated placement in high-volume automotive PCB assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 170 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC rail margin for 170 V nominal systems. |
| VBR min/max | 189–209 V @ 1 mA - Breakdown voltage range confirming reliable avalanche initiation within specification tolerance. |
| VC @ IPPM | 275 V @ 1.1 A - Clamping voltage during 10/1000 µs surge; determines worst-case overvoltage seen by protected ICs. |
| PPPM | 400 W - Peak pulse power capability; supports transient energy absorption up to 400 W for ≤1 ms pulses. |
| IR @ VWM | ≤1.1 µA - Reverse leakage at rated stand-off voltage; ensures minimal power loss and signal integrity in high-impedance circuits. |
| TJ max | 150 °C - Maximum junction temperature; enables operation in under-hood automotive environments with thermal derating. |
Pinout & Package
DO-214AC (SMA) surface-mount package: 2-terminal unidirectional configuration with cathode band marking; case dimensions per JEDEC DO-214AC standard; weight ≈0.060 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to system ground or lowest potential node; completes clamping path during positive transients. |
| Cathode | High-side surge input terminal | Connected to protected line (e.g., +170 V rail); avalanche conduction occurs when voltage exceeds VBR relative to anode. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including temperature cycling, HTRB, and ESD - enables use in engine control, ADAS, and body modules. |
| Glass passivated junction | Enhances long-term reliability and moisture resistance versus epoxy-passivated alternatives; critical for under-hood longevity. |
| Fast response time <1.0 ps | Clamps transients before sensitive downstream components experience damaging overvoltage - essential for protecting CAN/LIN transceivers and microcontrollers. |
| Meets ISO 7637-2 Pulse 1/2a/2b/3a/3b | Complies with automotive load dump and inductive switching immunity standards - eliminates need for additional external filtering in OEM designs. |
Applications
| Automotive On-Board DC/DC Converter | Industrial SMPS Input Stage |
|---|---|
Use Scenario: Protecting primary-side MOSFET gate drivers and controller ICs from load dump transients in 24 V/48 V vehicle DC/DC modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed across input bus to clamp ISO 7637-2 Pulse 2b (inductive switch-off) and Pulse 5a (load dump) surges. Use Value: Limits clamped voltage to 275 V, preventing gate oxide breakdown in 300 V-rated controllers while maintaining <1.1 µA leakage at 170 V nominal bus. | Use Scenario: Safeguarding rectifier output and PFC stage inputs in industrial 170 V-rated AC-DC power supplies exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Standoff-rated TVS mounted at secondary-side DC bus to absorb 10/1000 µs line-to-ground transients per IEC 61000-4-5 Level 4. Use Value: Delivers 400 W peak pulse power handling with 189–209 V VBR tolerance, ensuring consistent clamping performance across manufacturing lot variations. |
| LED Driver Power Input | Rail Voltage Supervisor Interface |
Use Scenario: Overvoltage protection for constant-current LED drivers used in commercial lighting systems with unstable 170 V DC distribution. IC Role / Device Role / Timing Role: Unidirectional TVS connected between LED string anode and ground to suppress switching spikes from nearby motor drives. Use Value: Fast <1.0 ps response prevents LED driver IC latch-up; low 1.1 µA IR avoids false triggering of under-voltage lockout circuits. | Use Scenario: Protecting voltage supervisor inputs monitoring 170 V auxiliary rails in telecom power shelves and server PSUs. IC Role / Device Role / Timing Role: High-VWM TVS placed directly at supervisor IC input pin to shunt ESD and fast transients before internal comparator damage. Use Value: 275 V VC ensures supervisor remains functional during 1 kV EFT bursts; DO-214AC footprint allows compact placement adjacent to IC pin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ170H | Higher VBR range (189–231 V) and higher VC (304 V); same VWM and PPPM. | Less precise clamping; higher let-through voltage may risk downstream 300 V-rated components. | Select SMAJ170AH when tighter VBR tolerance and lower clamping voltage are required for margin-critical 170 V systems. |
| SMBJ170AH | Same VWM/VBR/VC specs but in DO-214AA (SMB) package - larger footprint, higher thermal mass, 600 W PPPM rating. | Used where board space permits larger package and higher surge endurance is needed beyond 400 W. | Choose SMBJ170AH only if layout allows SMB footprint and system-level testing requires >400 W pulse handling. |
Compared with SMAJ170H and SMBJ170AH, the SMAJ170AH offers the optimal balance of tight VBR tolerance (±5.3%), low clamping voltage (275 V), and compact DO-214AC packaging - making it preferred for space-constrained automotive and industrial DC/DC designs requiring AEC-Q101 compliance and predictable surge response.
Availability
SMAJ170AH is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial SMPS input stages, and LED driver power inputs requiring stable component supply with full traceability and lifecycle management.
Supply support for SMAJ170AH 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, MOSFETs, and power management devices.
The SMAJ series is part of TSC's AEC-Q101-qualified transient suppression portfolio, engineered specifically for automotive and industrial power rail protection where reliability under harsh electrical and thermal conditions is mandatory.
FAQ
What is the clamping voltage of the SMAJ170AH under standard 10/1000 µs surge conditions?
The SMAJ170AH has a maximum clamping voltage (VC) of 275 V when subjected to its rated peak impulse current (IPPM) of 1.1 A using the standardized 10/1000 µs waveform. This value is measured at TA = 25 °C and represents the upper limit of voltage imposed on the protected circuit during surge events - critical for verifying compatibility with downstream component voltage ratings in 170 V systems.
Is the SMAJ170AH unidirectional or bidirectional, and how is polarity identified?
The SMAJ170AH is a unidirectional TVS diode, indicated by the absence of "CAH" or "CH" suffix and confirmed by its single-polarity electrical specifications. Polarity is marked on the DO-214AC package via a cathode band - the banded end connects to the protected line (high-side), while the unbanded end connects to ground (anode). This configuration enables clamping only for positive transients relative to ground.
Does the SMAJ170AH meet automotive qualification standards?
Yes, the SMAJ170AH is AEC-Q101 qualified, having passed stress tests including high-temperature reverse bias (HTRB), temperature cycling, and ESD per JESD22-A114. It also meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements - making it suitable for front-end protection in automotive ECUs, body control modules, and ADAS power supplies.
What is the maximum steady-state power dissipation rating for the SMAJ170AH?
The SMAJ170AH has a steady-state power dissipation (PD) rating of 1 W at TA = 25 °C, as specified in its Absolute Maximum Ratings table. This value applies to continuous DC reverse-bias conditions and must be thermally derated linearly above 25 °C ambient per the pulse derating curve in the datasheet - important for thermal design in enclosed automotive enclosures.
How does the SMAJ170AH differ from the SMAJ170H in terms of electrical performance?
The SMAJ170AH has a tighter breakdown voltage range (189–209 V) versus SMAJ170H (189–231 V), resulting in lower maximum clamping voltage (275 V vs. 304 V) and improved consistency in surge suppression. Both share identical VWM (170 V), PPPM (400 W), and package (DO-214AC), but the "A" variant provides superior VBR tolerance for designs requiring precise clamping thresholds.
SMAJ170AH 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):
- 170V
- Voltage - Breakdown (Min):
- 189V
- Voltage - Clamping (Max) @ Ipp:
- 275V
- Current - Peak Pulse (10/1000µs):
- 1.1A
- 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)
SMAJ170AH FAQ
1.How can I place an order for SMAJ170AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ170AH 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 SMAJ170AH reliable?
The price and inventory of SMAJ170AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ170AH is usually 5 days.
3.What payment methods are accepted for SMAJ170AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ170AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ170AH?
SMAJ170AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ170AH 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 SMAJ170AH?
For technical support, including SMAJ170AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ170AH requirements.
6.How does Aetrix verify that SMAJ170AH is sourced from the original manufacturer or authorized distributors?
All SMAJ170AH 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 SMAJ170AH meets industry standards.
7.What is the process for return or replacement of SMAJ170AH?
All SMAJ170AH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ170AH, 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 SMAJ170AH part is unused and in its original packaging.
Return procedure for SMAJ170AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ170AH 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 …
