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Taiwan Semiconductor Corporation SMAJ188CH
- Part No.:
- SMAJ188CH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ188CH.pdf
- Description:
- TVS DIODE 188VWM 344VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,724
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Product details
Overview
SMAJ188CH from Taiwan Semiconductor is a bidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy surge protection in automotive and industrial DC power lines. It features a 188 V working stand-off voltage (VWM), 209–255 V breakdown voltage (VBR), 344 V maximum clamping voltage (VC) at 0.9 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - meeting ISO 7637-2 Pulse 1/2a/2b/3a/3b requirements for vehicle electronics.
For engineers reviewing the SMAJ188CH datasheet, SMAJ188CH pinout, SMAJ188CH application, or SMAJ188CH equivalent, this device is selected for robust overvoltage protection in on-board DC/DC converters, SMPS input stages, lighting drivers, and automotive infotainment power rails where fast response (<1.0 ps), low leakage (<1 µA at VWM), and AEC-Q101 qualification are critical.
Technical Context
The SMAJ188CH is a unidirectional/bidirectional TVS diode in DO-214AC (SMA) package, configured as a single silicon junction with glass passivation. Its clamping behavior is defined by avalanche breakdown under transient overvoltage, delivering sub-nanosecond response and stable performance across -55°C to +150°C junction temperature range.
It operates with 188 V DC stand-off capability and clamps transients up to 344 V at 0.9 A (10/1000 µs), supporting 400 W peak pulse power below 78 V and 300 W above - consistent with IEC 61000-4-5 Level 4 surge immunity requirements when applied with appropriate series impedance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 188 V - Maximum continuous reverse operating voltage before clamping initiates; sets system DC rail compatibility. |
| VBR min/max | 209–255 V @ 1 mA - Confirmed avalanche onset range; ensures reliable triggering above normal operating margin. |
| VC @ IPPM | 344 V @ 0.9 A (10/1000 µs) - Clamped voltage during worst-case surge; defines protected circuit's maximum stress level. |
| PPPM | 400 W (10/1000 µs) - Peak transient energy absorption capacity; validates compliance with ISO 7637-2 Pulse 5a. |
| IR @ VWM | <1 µA - Negligible leakage at rated stand-off; avoids power loss or false triggering in high-impedance bias networks. |
| TJ max | +150 °C - Enables placement near hot components (e.g., MOSFETs, inductors) in engine bay or power supply modules. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with matte tin-plated leads; compatible with J-STD-002 soldering. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with cathode band marking; polarity-sensitive for unidirectional variants, but SMAJ188CH is bidirectional - no polarity dependence in circuit layout. Leads are matte tin-plated per J-STD-002; moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional transient conduction path | Both terminals function identically under reverse or forward surge; no orientation required during placement. |
| Case | Non-electrical mechanical interface | No internal connection; serves only as thermal mass and mounting structure; no grounding requirement. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood and powertrain applications per stress test conditions including temperature cycling, HTRB, and ESD. |
| ISO 7637-2 compliance | Passes Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling) without degradation. |
| Fast response time | <1.0 ps from 0 V to VBR - limits voltage overshoot before clamping engages, protecting downstream FETs and controllers. |
| Glass passivated junction | Enhances long-term reliability and stability of breakdown characteristics under thermal and humidity stress. |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - suitable for green manufacturing and export-compliant designs. |
Applications
| Automotive Infotainment Power Rail | On-Board DC/DC Converter Input |
|---|---|
Use Scenario: Protecting USB-C PD, display, and audio subsystems from load-dump surges in 12 V vehicle battery systems. IC Role / Device Role / Timing Role: Bidirectional TVS placed at DC input filter stage to clamp transients before LDOs and PMICs. Use Value: Withstands 344 V clamping at 0.9 A, enabling survival of ISO 7637-2 Pulse 5a (load dump) without derating external components. |
Use Scenario: Safeguarding isolated flyback or buck-boost converter inputs against switching noise and line-induced spikes. IC Role / Device Role / Timing Role: Primary surge suppression element upstream of input capacitor and controller IC. Use Value: 400 W peak power rating and <1 µA leakage preserve efficiency while ensuring >100,000 surge cycles per MIL-STD-883H Method 3015.8. |
| LED Headlamp Driver Module | Industrial SMPS Front-End |
Use Scenario: Shielding constant-current LED drivers from alternator ripple and ignition coil coupling in automotive lighting. IC Role / Device Role / Timing Role: Parallel-connected TVS across input bulk capacitor to absorb repetitive 100 ns–1 ms transients. Use Value: 150 °C max junction temperature supports operation adjacent to high-power LED thermal pads without thermal runaway risk. |
Use Scenario: Hardening AC-DC adapter or DIN-rail power supply inputs against lightning-induced surges and EFT bursts. IC Role / Device Role / Timing Role: First-line transient suppressor before bridge rectifier and PFC stage. Use Value: Bidirectional symmetry eliminates orientation errors during automated assembly; DO-214AC footprint enables high-density PCB layouts. |
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 SMAJ188A | Same VWM (188 V), lower VBR min (209 V vs. 209 V), identical VC (328 V @ 0.9 A), same DO-214AC package. | Also AEC-Q101 qualified and ISO 7637-2 compliant; differs only in tighter VBR tolerance (209–231 V vs. 209–255 V). | Select SMAJ188A if tighter breakdown consistency is required for precision clamping threshold control. |
| ON Semiconductor SMAJ188CA | VWM = 188 V, VBR = 209–255 V, VC = 344 V @ 0.9 A, same 400 W rating, DO-214AC package, AEC-Q101 qualified. | Identical electrical specs and automotive qualification; differs in tape-and-reel packaging standard (EIA-481 vs. TSC's custom reel). | Choose SMAJ188CA for dual-sourcing flexibility with identical performance and second-source validation. |
Compared with SMAJ188CH, SMAJ188A offers tighter VBR distribution for improved batch-to-batch clamping predictability, while SMAJ188CA provides identical electrical behavior with alternate logistics support - both require no PCB redesign and maintain full functional equivalence in automotive and industrial surge protection roles.
Availability
SMAJ188CH is available at Aetrix Electronics and suitable for automotive infotainment systems, on-board DC/DC converters, and LED lighting modules requiring stable component supply across extended temperature ranges and high-reliability production cycles.
Supply support for SMAJ188CH 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 MOSFETs since 1979.
The SMAJ series was developed specifically for AEC-Q101-compliant automotive transient suppression, emphasizing robustness in harsh environments, tight parametric control, and seamless integration into automated SMT lines.
FAQ
What is the clamping voltage of SMAJ188CH under a 10/1000 µs surge?
The SMAJ188CH clamps to a maximum of 344 V when subjected to a 10/1000 µs waveform at 0.9 A peak impulse current. This value is measured per standard test conditions in the datasheet and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ188CH maintains this clamping performance across its full operating temperature range (-55°C to +150°C).
Is SMAJ188CH unidirectional or bidirectional?
SMAJ188CH is a bidirectional TVS diode, indicated by the "CH" suffix per Taiwan Semiconductor's ordering nomenclature. Unlike unidirectional variants (e.g., SMAJ188H), it conducts symmetrically in both polarities - eliminating orientation constraints during PCB layout and enabling use in AC-coupled or floating DC bus protection. Its electrical specifications apply identically in either direction.
Does SMAJ188CH meet AEC-Q101 requirements?
Yes, SMAJ188CH is explicitly qualified to AEC-Q101 Rev D for stress testing including HTGB, HTRB, TCT, and ESD. The qualification applies to the full DO-214AC packaged device and covers the entire specified operating temperature range. This makes SMAJ188CH suitable for automotive powertrain, body electronics, and ADAS subsystems where component reliability is mission-critical.
What is the maximum steady-state power dissipation for SMAJ188CH?
The SMAJ188CH has a maximum steady-state power dissipation (PD) of 1 W at 25°C ambient, as specified in its Absolute Maximum Ratings table. This rating applies only to continuous DC or low-frequency reverse bias conditions - not transient surges. For sustained operation, thermal design must ensure junction temperature remains ≤150°C, typically requiring minimal copper area due to the device's low leakage (<1 µA at 188 V).
How does SMAJ188CH differ from SMAJ188AH?
SMAJ188CH and SMAJ188AH share identical VWM (188 V), VBR range (209–255 V), and VC (344 V), but SMAJ188AH has a tighter VBR window (209–231 V) and lower clamping voltage (328 V). The "A" suffix denotes tighter parameter tolerances, while "CH" indicates bidirectional configuration. Both are AEC-Q101 qualified and packaged in DO-214AC; SMAJ188CH is preferred when symmetrical surge handling is required.
SMAJ188CH 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):
- 188V
- Voltage - Breakdown (Min):
- 209V
- Voltage - Clamping (Max) @ Ipp:
- 344V
- Current - Peak Pulse (10/1000µs):
- 900mA
- 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)
SMAJ188CH FAQ
1.How can I place an order for SMAJ188CH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ188CH 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 SMAJ188CH reliable?
The price and inventory of SMAJ188CH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ188CH is usually 5 days.
3.What payment methods are accepted for SMAJ188CH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ188CH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ188CH?
SMAJ188CH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ188CH 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 SMAJ188CH?
For technical support, including SMAJ188CH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ188CH requirements.
6.How does Aetrix verify that SMAJ188CH is sourced from the original manufacturer or authorized distributors?
All SMAJ188CH 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 SMAJ188CH meets industry standards.
7.What is the process for return or replacement of SMAJ188CH?
All SMAJ188CH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ188CH, 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 SMAJ188CH part is unused and in its original packaging.
Return procedure for SMAJ188CH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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