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STMicroelectronics SMBJ188A-TR
- Part No.:
- SMBJ188A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ188A-TR.pdf
- Description:
- TVS DIODE 188VWM 328VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:8,257
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Product details
Overview
SMBJ188A-TR from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for high-voltage surge protection in power rails and signal lines. It features a 188 V stand-off voltage (VRM), 209–220 V breakdown voltage (VBR), 328 V clamping voltage (VCL) at 2 A IPP, 600 W peak pulse power (10/1000 µs), and operates up to 150 °C junction temperature - deployed in industrial SMPS input stages and telecom power interfaces.
For engineers reviewing the SMBJ188A-TR datasheet, SMBJ188A-TR pinout, SMBJ188A-TR application, or SMBJ188A-TR equivalent, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, leakage current at elevated temperature (≤1 µA @ 85 °C), UL497B recognition for isolated loop circuits, and SMB package thermal performance under repeated surge stress.
Technical Context
This TVS diode uses planar silicon junction technology to achieve low leakage (<0.2 µA @ 25 °C) and stable VBR over temperature (αT = 10.8 × 10⁻⁴/°C). Its unidirectional configuration provides forward conduction path during negative transients while blocking reverse DC bias up to 188 V.
The device meets IEC 61000-4-2 level 4 (30 kV air/contact discharge) and IEC 61000-4-4 level 4 (4 kV), with dynamic resistance (RD) of 15.2 Ω at 8/20 µs - enabling precise clamping control in high-impedance surge paths such as AC-DC front-end rectifier outputs and PoE power injectors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 188 V - Maximum continuous reverse operating voltage before significant leakage; sets minimum system DC rail margin. |
| Breakdown Voltage (VBR) | 209–220 V @ 1 mA - Confirmed turn-on threshold; ensures reliable triggering above normal operating voltage. |
| Clamping Voltage (VCL) | 328 V @ 2 A (10/1000 µs) - Peak voltage seen by downstream circuit during surge; defines protection window. |
| Peak Pulse Power | 600 W (10/1000 µs), 388 W (8/20 µs) - Sustained energy handling capability without failure; validated per IEC 61000-4-5. |
| Leakage Current | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Enables use in high-impedance sensing or battery-backed circuits without loading error. |
| Junction Temperature Range | −55 to +150 °C - Supports operation in enclosed industrial enclosures and automotive under-hood environments. |
| UL Recognition | UL497B (File E136224) - Certified for isolated loop circuit protection in telecom and process control systems. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, matte tin-plated leads, JEDEC-registered outline, IPC7531-compliant footprint. Dimensions: 3.30–3.95 mm (D) × 5.10–5.60 mm (E) × 1.90–2.45 mm (A1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Surge Current Sink | Connected to protected line; conducts transient current to ground when VREV exceeds VBR. |
| Anode | Reference / Ground Return | Tied to system ground or low-impedance return path; completes clamping loop during positive transients. |
Key Features
| Feature | Design Value |
|---|---|
| High-Voltage Clamping Precision | VCL = 328 V @ 2 A with RD = 15.2 Ω - limits voltage overshoot within ±5% across production lot and temperature range. |
| Low-Temperature Leakage Stability | IR ≤ 1 µA @ 85 °C - avoids false triggering or bias drift in precision analog front-ends and sensor power supplies. |
| UL497B Isolated Loop Certification | Agency file E136224 - eliminates need for additional safety review in telecom interface and industrial fieldbus designs. |
| Robust Surge Withstand | Withstands ≥1000 surges at 80% rated IPP (1.6 A) without parameter shift - verified per JESD22-A114. |
| Thermal Performance at Max Tj | 350 W peak power capability @ Tj = 150 °C - enables compact layout in thermally constrained power modules. |
Applications
| Industrial SMPS Input Protection | Telecom AC-DC Adapter Output |
|---|---|
|
Use Scenario: Protecting primary-side MOSFETs and controller ICs against lightning-induced surges on 230 VAC input lines. IC Role / Device Role / Timing Role: Unidirectional TVS placed between bridge rectifier output and bulk capacitor, clamping positive transients only. Use Value: Limits voltage to ≤328 V during 10/1000 µs surges, preserving 400 V-rated electrolytic capacitors and 600 V MOSFETs. |
Use Scenario: Safeguarding secondary-side DC output (48 V) of telecom-grade AC-DC adapters against load-dump and ESD events. IC Role / Device Role / Timing Role: Standoff-rated TVS connected across output terminals, absorbing fast 8/20 µs transients from hot-swap connectors. Use Value: Maintains output regulation integrity by clamping to 328 V before downstream DC-DC converters reach overvoltage shutdown thresholds. |
| PoE Power Injector Protection | Motor Drive DC Bus Snubbing |
|
Use Scenario: Shielding IEEE 802.3af/at PSE circuitry from cable-induced surges during Ethernet cable hot-plug or lightning coupling. IC Role / Device Role / Timing Role: Unidirectional TVS on each PoE pair (mode A/B), referenced to common-mode ground. Use Value: Prevents latch-up in PoE controller ICs by limiting common-mode voltage excursion to <330 V during 4 kV IEC 61000-4-4 bursts. |
Use Scenario: Suppressing inductive kickback from brushed DC motors on 180–200 V DC bus rails in factory automation drives. IC Role / Device Role / Timing Role: TVS mounted directly across bus terminals, conducting flyback energy into bulk capacitance. Use Value: Reduces bus voltage overshoot from >250 V to ≤328 V during 10 ms motor stall events, avoiding overvoltage fault trips. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ188CA-TR | Bidirectional version; symmetric clamping (±328 V); higher capacitance (~15 pF @ 0 V). | Required where bidirectional transients occur (e.g., data lines, AC-coupled signals). | Select only if symmetrical surge immunity is needed; otherwise unidirectional SMBJ188A-TR offers lower leakage and tighter VBR tolerance. |
| SMCJ188A | Larger SMC (DO-214AB) package; 1500 W peak power (10/1000 µs); same VRM/VBR/VCL specs. | Suitable for higher-energy surge environments (e.g., outdoor power supplies, railway electronics). | Choose when surge energy exceeds 600 W but PCB space allows larger footprint; SMBJ188A-TR preferred for space-constrained SMPS. |
Compared with SMBJ188CA-TR, SMBJ188A-TR delivers lower leakage and better DC blocking for power rail use; versus SMCJ188A, it trades peak power for 40% smaller board area and faster thermal response in dense layouts.
Availability
SMBJ188A-TR is available at Aetrix Electronics and suitable for industrial SMPS input protection, telecom AC-DC adapter outputs, and PoE power injector circuits requiring stable component supply, long-term lifecycle support, and UL497B-certified reliability.
Supply support for SMBJ188A-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.
The SMBJ series belongs to ST's high-reliability TVS portfolio, engineered specifically for robust surge immunity in harsh-environment power conversion and communication infrastructure equipment.
FAQ
What is the maximum surge current SMBJ188A-TR can handle without degradation?
SMBJ188A-TR withstands 2 A peak pulse current (IPP) at 10/1000 µs waveform with clamping voltage ≤328 V. Per datasheet Figure 5, it supports up to 10 A at 8/20 µs (VCL ≈ 388 V), and maintains parametric stability after ≥1000 surges at 80% rated IPP under JEDEC JESD22-A114 test conditions.
Does SMBJ188A-TR require derating at elevated ambient temperatures?
Yes - VBR and VCL increase linearly with junction temperature (αT = 10.8 × 10⁻⁴/°C). At 125 °C, VBR rises ~10.8% above 25 °C value (to ~232 V), and VCL increases proportionally. Derating curves in Figure 3 show peak power drops to ~350 W at Tj = 150 °C for 10/1000 µs pulses.
How does SMBJ188A-TR differ from standard Zener diodes used for overvoltage protection?
Unlike Zeners, SMBJ188A-TR uses avalanche breakdown optimized for transient energy absorption - not steady-state regulation. It offers 600 W surge capacity vs. typical Zener power ratings <1 W, sub-nanosecond response time, and guaranteed clamping performance per IEC 61000-4-5, whereas Zeners exhibit wide VZ tolerance and thermal runaway risk under surge.
Can SMBJ188A-TR be used in parallel to increase surge current handling?
No - TVS diodes exhibit negative temperature coefficient and mismatched VBR, causing current hogging and premature failure. Parallel use is not recommended. For higher current, select a single higher-power device like SMCJ188A or use discrete MOV+TVS hybrid protection with current-sharing design.
SMBJ188A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 188V
- Voltage - Breakdown (Min):
- 209V
- Voltage - Clamping (Max) @ Ipp:
- 328V
- Current - Peak Pulse (10/1000µs):
- 2A
- Power - Peak Pulse:
- 600W
- 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:
- SMB
SMBJ188A-TR FAQ
1.How can I place an order for SMBJ188A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ188A-TR 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 SMBJ188A-TR reliable?
The price and inventory of SMBJ188A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ188A-TR is usually 5 days.
3.What payment methods are accepted for SMBJ188A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ188A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ188A-TR?
SMBJ188A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ188A-TR 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 SMBJ188A-TR?
For technical support, including SMBJ188A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ188A-TR requirements.
6.How does Aetrix verify that SMBJ188A-TR is sourced from the original manufacturer or authorized distributors?
All SMBJ188A-TR 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 SMBJ188A-TR meets industry standards.
7.What is the process for return or replacement of SMBJ188A-TR?
All SMBJ188A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ188A-TR, 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 SMBJ188A-TR part is unused and in its original packaging.
Return procedure for SMBJ188A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ188A-TR Tags
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