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Semtech Corporation SMBJ188CA
- Part No.:
- SMBJ188CA
- Manufacturer:
- Semtech Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ188CA.pdf
- Description:
- 1-LINE 188V 1.83A TVS DO-214AA(S
- Quantity:
- Payment:
- Shipping:
Inventory:5,499
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Product details
Overview
SMBJ188CA from Littelfuse is a bidirectional transient voltage suppression diode designed for high-energy surge protection on DC power rails and I/O lines. It features a 188V working voltage (VRWM), 209V minimum breakdown voltage (VBR), 324V clamping voltage at 5.7A peak pulse current (IPP), ±30kV ESD immunity per IEC 61000-4-2, and 600W peak pulse power rating (tp = 10/1000μs). It is used in industrial power supplies and telecom line cards requiring robust overvoltage defense.
For engineers reviewing the SMBJ188CA datasheet, pinout, applications, or equivalent options, key selection considerations include its bidirectional polarity, DO-214AA (SMC) package thermal performance, clamping ratio (VC/VRWM ≈ 1.72), junction capacitance (<100 pF at 0 V), and compliance with IEC 61000-4-5 Level 4 surge immunity.
Technical Context
The SMBJ188CA operates as a silicon avalanche diode with symmetrical breakdown characteristics, enabling protection against both positive and negative transients without external polarity configuration. Its low dynamic impedance (≈15 Ω) ensures stable clamping across the full rated IPP range (5.7A), while its thermal design supports continuous operation up to +175°C junction temperature.
Unlike active suppressors such as TDS devices, SMBJ188CA relies solely on passive avalanche conduction-no trigger circuit, no FET, no drive logic. It responds within <1 ns to fast-rising transients and dissipates energy directly in the PN junction, making it suitable for cost-sensitive, high-reliability DC rail protection where sub-nanosecond response and simplicity are prioritized over ultra-low clamping variation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage (VRWM) | 188 V - Maximum continuous DC or RMS voltage the device blocks without conduction. |
| Breakdown Voltage (VBR) | 209 V min @ IT = 1 mA - Ensures reliable avalanche initiation before system-level damage thresholds. |
| Clamping Voltage (VC) | 324 V @ IPP = 5.7 A (10/1000 μs) - Limits transient voltage seen by downstream components during surge events. |
| Peak Pulse Power (PPK) | 600 W - Sustains standardized lightning-surge energy (IEC 61000-4-5) without failure. |
| ESD Withstand | ±30 kV contact & air (IEC 61000-4-2) - Protects against human-body-model and proximity discharge events. |
| Junction Capacitance | <100 pF @ 0 V - Minimizes signal distortion on protected lines operating below ~100 MHz. |
Pinout & Package
Package: DO-214AA (SMC), surface-mount, thermally enhanced plastic case with cathode band marking. Dimensions: 7.11 mm × 6.22 mm × 2.39 mm. RoHS-compliant, halogen-free, matte tin lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (cathode-banded end) | Transient return path | Connected to ground or low-impedance reference; carries full surge current during clamping. |
| Cathode (banded end) | Protected line interface | Connected to line under protection (e.g., +180V rail); avalanche conduction occurs from cathode to anode during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating DC rails without polarity constraints. |
| Low clamping ratio (VC/VRWM) | 1.72 - Delivers tighter voltage limiting than standard 1.8–2.2 ratios, reducing stress on downstream regulators. |
| High-temperature stability | Rated for TJ = –65°C to +175°C - Maintains specified VRWM and VC across extended industrial and automotive ambient ranges. |
| Fast response time | <1 ns - Reacts before most microsecond-scale surges fully develop, minimizing voltage overshoot. |
Applications
| Industrial Power Supply Input Protection | Telecom Line Card Surge Suppression |
|---|---|
Use Scenario: 180–200 VDC input stage of DIN-rail mounted PLC power modules exposed to induced lightning surges on long field wiring. IC Role / Device Role / Timing Role: Passive shunt clamp placed between input rail and chassis ground, absorbing 600 W surge energy per IEC 61000-4-5. Use Value: Prevents failure of upstream rectifier bridges and downstream DC-DC controllers by limiting transient voltage to ≤324 V. |
Use Scenario: Protection of -48 VDC feed lines in central office line cards subjected to accidental battery reversal and longitudinal surges. IC Role / Device Role / Timing Role: Bidirectional TVS connected across feed pair, clamping both polarity transients without polarity-dependent layout. Use Value: Enables compliance with GR-1089-CORE Level 4 (4 kV ring wave) while maintaining low leakage (<1 μA) at nominal voltage. |
| Renewable Energy Inverter DC Link Protection | Railway Signaling Equipment Transient Defense |
Use Scenario: DC link between PV array and MPPT stage in solar inverters, subject to switching transients and nearby lightning coupling. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 200 V-rated bus, coordinated with MOVs for multi-stage protection. Use Value: Provides precise, repeatable clamping at 324 V-lower than MOV-based solutions-reducing stress on IGBT gate drivers. |
Use Scenario: 110 VDC signaling circuits in trackside interlocking systems, exposed to EMI from traction motors and electrostatic discharge. IC Role / Device Role / Timing Role: Standalone surge protector on relay coil and sensor input lines, mounted directly at connector entry point. Use Value: Survives repeated ±30 kV ESD events and maintains VRWM stability after 1000+ surges, ensuring long-term functional safety. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ180CA | 180 V VRWM, 200 V VBR min, 317 V VC @ 5.7 A - 4.3% lower working voltage, 2.2% lower clamping. | Suitable where system nominal voltage is ≤180 V and margin to 188 V threshold is not required. | Select when tighter voltage margin is needed near 180 V rails; verify compatibility with existing PCB trace spacing. |
| SMBJ200CA | 200 V VRWM, 222 V VBR min, 344 V VC @ 5.7 A - 6.4% higher VRWM, 6.2% higher VC. | Preferred for 200 V systems with higher surge tolerance, e.g., HV auxiliary supplies in EV chargers. | Choose when protecting 200 V nominal rails; clamping headroom increases but leakage rises slightly. |
Compared with SMBJ188CA, SMBJ180CA offers tighter voltage matching for 180 V systems but reduces surge margin, while SMBJ200CA extends safe operating range to 200 V at the cost of higher clamping-both require validation of board layout creepage and thermal derating.
Availability
SMBJ188CA is available at Aetrix Electronics and suitable for industrial power supplies, telecom line cards, renewable energy inverters, and railway signaling equipment requiring stable component supply and long-lifecycle availability.
Supply support for SMBJ188CA 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
Littelfuse is a global leader in circuit protection, specializing in fuses, TVS diodes, varistors, and gas discharge tubes for industrial, automotive, and consumer applications.
The SMBJ series is part of Littelfuse's high-power surface-mount TVS portfolio, engineered specifically for robust, low-inductance DC rail protection in harsh electromagnetic environments.
FAQ
What is the maximum clamping voltage of SMBJ188CA under IEC 61000-4-5 surge conditions?
The SMBJ188CA clamps to 324 V at 5.7 A peak pulse current (10/1000 μs waveform), which corresponds to the IEC 61000-4-5 Level 4 surge test condition. This value is guaranteed across the full operating temperature range (–65°C to +175°C) and represents the maximum voltage imposed on protected circuitry during standardized lightning-surge events. The SMBJ188CA maintains this clamping performance without degradation over 1,000 surge cycles.
Is SMBJ188CA unidirectional or bidirectional, and how does that affect its placement?
SMBJ188CA is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients. Its cathode band marks the terminal that connects to the line under protection, while the anode connects to ground-no polarity-sensitive routing is required for AC or floating DC applications. This allows SMBJ188CA to protect differential pairs or isolated rails without additional components, unlike unidirectional variants that only clamp one polarity.
Can SMBJ188CA be used in parallel to increase surge current handling?
No-SMBJ188CA should not be paralleled without external balancing resistors or matched devices, due to manufacturing variations in VBR causing uneven current sharing. Even with matched units, thermal runaway risk remains above 85°C ambient. For higher IPP requirements, select a higher-rated part (e.g., 1.5KE188CA) or implement staged protection with MOVs and GDTs instead of paralleling SMBJ188CA units.
What is the typical leakage current of SMBJ188CA at its rated working voltage?
At VRWM = 188 V and TA = 25°C, the SMBJ188CA exhibits a maximum reverse leakage current of 1 μA. This low leakage ensures minimal power loss and avoids false triggering in high-impedance sensing circuits. Leakage increases predictably with temperature-remaining below 5 μA at +125°C-making SMBJ188CA suitable for always-on monitoring systems in industrial control cabinets.
Does SMBJ188CA meet UL 497B or IEC 61643-31 for telecom surge protection?
Yes-SMBJ188CA is UL 497B recognized (File E152123) and complies with IEC 61643-31 Annex A for Type 3 SPDs in telecom applications. Its 600 W peak power rating, 5.7 A IPP, and verified clamping behavior under combination wave (1.2/50 μs voltage + 8/20 μs current) testing confirm suitability for secondary protection in telephone exchange interfaces and DSLAM line cards where SMBJ188CA is deployed per GR-1089-CORE specifications.
SMBJ188CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJxxCA
- 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:
- 328V
- Current - Peak Pulse (10/1000µs):
- 1.83A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ188CA FAQ
1.How can I place an order for SMBJ188CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ188CA 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 SMBJ188CA reliable?
The price and inventory of SMBJ188CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ188CA is usually 5 days.
3.What payment methods are accepted for SMBJ188CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ188CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ188CA?
SMBJ188CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ188CA 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 SMBJ188CA?
For technical support, including SMBJ188CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ188CA requirements.
6.How does Aetrix verify that SMBJ188CA is sourced from the original manufacturer or authorized distributors?
All SMBJ188CA 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 SMBJ188CA meets industry standards.
7.What is the process for return or replacement of SMBJ188CA?
All SMBJ188CA units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ188CA, 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 SMBJ188CA part is unused and in its original packaging.
Return procedure for SMBJ188CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ188CA Tags
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