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Microchip Technology MPLAD18KP33A
- Part No.:
- MPLAD18KP33A
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MPLAD18KP33A.pdf
- Description:
- TVS DIODE 33VWM 53.3VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:9,988
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Product details
Overview
MPLAD18KP33A from Microsemi is a unidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace, automotive, and industrial power systems. It delivers 18,000 W peak pulse power at 10/1000 μs, clamps at ≤53.3 V under 338 A peak impulse current, and features a 33 V reverse standoff voltage (VWM) with 36.7–40.6 V breakdown range. It is widely deployed in aircraft lightning protection per RTCA DO-160 Section 22 and secondary surge suppression per IEC 61000-4-5.
For engineers reviewing the MPLAD18KP33A datasheet, MPLAD18KP33A pinout, MPLAD18KP33A application, or MPLAD18KP33A equivalent, this device is selected for high-reliability DC bus protection where low thermal resistance (RθJC = 0.7 °C/W), RoHS-compliant packaging, and multi-stroke lightning compliance are critical design requirements.
Technical Context
The MPLAD18KP33A employs a silicon avalanche diode structure optimized for fast response (<5 ns clamping time) and high cumulative energy handling. Its metal-base package enables direct thermal coupling to heatsinks, supporting sustained operation under repetitive transients at ≤0.05% duty factor. The device meets AEC-Q101 stress testing and supports MIL-PRF-19500 upscreening options for extended reliability.
It operates across –55°C to +150°C junction temperature, with 50 °C/W junction-to-ambient thermal resistance on FR4 PCB using recommended pad layout. Standby leakage is limited to 10 μA at 33 V, and forward clamping remains ≤2.0 V at 500 A - enabling robust protection of downstream MOSFETs and controllers without forward conduction losses compromising system efficiency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 μs) | 18,000 W - sustains full-rated lightning surge energy without degradation |
| Reverse Standoff Voltage (VWM) | 33 V - maximum continuous DC or peak AC voltage before clamping initiates |
| Breakdown Voltage (V(BR)) | 36.7–40.6 V @ I(BR) - ensures reliable avalanche turn-on margin above VWM |
| Max Clamping Voltage (VC) | 53.3 V @ 338 A - limits protected circuit voltage during worst-case surge |
| Peak Pulse Current (IPP) | 338 A - defines maximum single-event surge current capability |
| Junction-to-Case Thermal Resistance | 0.7 °C/W - enables efficient heat transfer to external heatsink or copper plane |
| Clamping Response Time | <5 ns - suppresses fast-rising transients before sensitive ICs are damaged |
Pinout & Package
Package: Surface-mount PLAD (Plastic Low-Profile Avalanche Diode) with metal base (cathode terminal). Dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H), weight ≈1 g. UL94V-0 epoxy body; matte-tin terminals solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (top surface) | Transient current entry point | Connected to protected line (e.g., 28 V DC bus); accepts surge current into device |
| Cathode (metal base) | Current return path / thermal interface | Must be soldered to large copper pour or heatsink; serves as primary thermal conduction path and circuit ground reference |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SMT construction | Enables placement on high-density boards without height clearance issues; compatible with automated assembly |
| RTCA DO-160F Waveform 4 & 5A compliance | Validated for Level 4 (6.4/69 μs) and Level 4 (40/120 μs) pin-injection immunity in avionics systems |
| IEC 61000-4-5 Class 1–5 support | Meets secondary lightning protection requirements across 2 Ω, 12 Ω, and 42 Ω source impedances |
| Moisture Sensitivity Level 1 | No dry-pack or baking required prior to reflow - reduces manufacturing overhead and moisture-related defects |
| AEC-Q101 qualified | Validated for automotive under-hood applications including load dump and ISO 7637-2 pulse testing |
Applications
| Aerospace Avionics Power Bus | Automotive 28 V DC Distribution |
|---|---|
Use Scenario: Protection of flight control electronics and sensor interfaces against lightning-induced surges per RTCA DO-160 Section 22. IC Role / Device Role / Timing Role: Primary transient shunt element on 28 V main power rail, clamping within 5 ns to prevent latch-up or gate oxide damage in downstream PMICs and FPGAs. Use Value: Enables compliance with multi-stroke lightning standard without derating - maintains 18 kW rating over ≥1000 surge events at 0.05% duty cycle. | Use Scenario: Load dump suppression in commercial aircraft auxiliary power units (APUs) and vehicle electrical systems. IC Role / Device Role / Timing Role: Unidirectional TVS placed between alternator output and battery-fed distribution bus to clamp 120 V/400 ms transients. Use Value: Withstands 1500 A forward surge (IFSM) and clamps below 53.3 V, protecting 36 V-rated DC-DC converters and CAN transceivers. |
| Industrial 48 V Telecom Power | Railway Traction Control Interface |
Use Scenario: Surge protection for 48 V intermediate bus in telecom rectifier modules exposed to induced lightning on outdoor cabling. IC Role / Device Role / Timing Role: Secondary protection stage after gas discharge tube (GDT), absorbing residual energy and limiting let-through voltage to <53.3 V. Use Value: RθJC = 0.7 °C/W allows direct mounting to chassis ground, reducing thermal impedance by >80% vs. standard SMD TVS packages. | Use Scenario: Input protection for traction motor controller gate drivers subjected to switching transients and EFT bursts per IEC 61000-4-4. IC Role / Device Role / Timing Role: Fast-clamping TVS on isolated 24 V auxiliary supply lines feeding optocouplers and level shifters. Use Value: 10 μA max ID at 33 V minimizes standby power loss; bidirectional variants (e.g., MPLAD18KP33CA) available if AC-coupled signal lines require symmetric clamping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33A (onsemi) | 600 W PPP rating, 33 V VWM, SMC package - 30× lower peak power than MPLAD18KP33A | Targeted at consumer-grade or non-safety-critical industrial use; not rated for DO-160 or IEC 61000-4-5 Class 4/5 | Select only for cost-sensitive, low-energy surge environments where 18 kW capability is unnecessary |
| SMCJ33A (Littelfuse) | 1500 W PPP, same VWM and package footprint - lacks metal-base thermal path and AEC-Q101 qualification | Used in general-purpose industrial controls; no DO-160 validation or upscreening options | Choose when board-level thermal management suffices and aerospace/automotive qualification is not required |
Compared with SMBJ33A and SMCJ33A, the MPLAD18KP33A provides 30× higher surge energy capacity, certified compliance with aviation lightning standards, and a thermally optimized metal-base package - making it irreplaceable in mission-critical power rail protection where failure is not an option.
Availability
MPLAD18KP33A is available at Aetrix Electronics and suitable for aerospace avionics, automotive 28 V systems, and industrial 48 V telecom power applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for MPLAD18KP33A 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
Microsemi Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened solutions for aerospace, defense, and industrial markets.
The MPLAD18KP33A belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for multi-stroke lightning protection and automotive load-dump immunity in safety-critical platforms.
FAQ
What is the clamping voltage of the MPLAD18KP33A at its rated peak pulse current?
The MPLAD18KP33A has a maximum clamping voltage (VC) of 53.3 V at its rated peak pulse current of 338 A under 10/1000 μs waveform conditions. This value is guaranteed across the full operating temperature range and ensures protected circuits remain below critical voltage thresholds during surge events. The clamping performance is validated per Figure 3 in RF01215 Rev B.
Does the MPLAD18KP33A meet RTCA DO-160 lightning protection requirements?
Yes, the MPLAD18KP33A is explicitly validated for RTCA DO-160F Section 22 multi-stroke lightning testing, including Waveform 4 (6.4/69 μs) Level 4 and Waveform 5A (40/120 μs) Level 4. Its 18,000 W peak pulse power rating and low clamping voltage enable compliance without external derating - a key requirement for certified avionics power systems.
How is thermal management implemented for the MPLAD18KP33A in high-duty-cycle applications?
The MPLAD18KP33A uses a metal-base PLAD package with 0.7 °C/W junction-to-case thermal resistance. Effective thermal management requires soldering the cathode (metal base) directly to a large copper pour or external heatsink. Per RF01215, thermal derating begins above 100°C case temperature, and steady-state power dissipation is limited to 71 W at TC = 100°C.
Is the MPLAD18KP33A RoHS compliant, and what is its moisture sensitivity level?
Yes, the MPLAD18KP33A is RoHS compliant (e3 marking), with IPC/JEDEC J-STD-020B Moisture Sensitivity Level 1 - meaning it can be stored indefinitely at ambient conditions and requires no dry packing or baking before reflow soldering. This simplifies manufacturing logistics and eliminates moisture-related popcorning risks.
What is the polarity configuration and marking convention for the MPLAD18KP33A?
The MPLAD18KP33A is a unidirectional TVS diode: the cathode is the metal base (underside), and the anode is the top metallized surface. Polarity is marked on the body per Microsemi standard; "A" suffix denotes unidirectional construction, while "CA" indicates bidirectional. No additional polarity markings are applied - orientation is defined solely by physical terminal assignment.
MPLAD18KP33A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- Nonstandard SMD
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 338A
- Power - Peak Pulse:
- 18000W (18kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Military
- Qualification:
- MIL-PRF-19500
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- PLAD
MPLAD18KP33A FAQ
1.How can I place an order for MPLAD18KP33A through Aetrix?
Please submit a Request for Quotation (RFQ) for MPLAD18KP33A 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 MPLAD18KP33A reliable?
The price and inventory of MPLAD18KP33A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPLAD18KP33A is usually 5 days.
3.What payment methods are accepted for MPLAD18KP33A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPLAD18KP33A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPLAD18KP33A?
MPLAD18KP33A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPLAD18KP33A 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 MPLAD18KP33A?
For technical support, including MPLAD18KP33A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPLAD18KP33A requirements.
6.How does Aetrix verify that MPLAD18KP33A is sourced from the original manufacturer or authorized distributors?
All MPLAD18KP33A 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 MPLAD18KP33A meets industry standards.
7.What is the process for return or replacement of MPLAD18KP33A?
All MPLAD18KP33A units undergo pre-shipment inspection (PSI). If there is an issue with MPLAD18KP33A, 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 MPLAD18KP33A part is unused and in its original packaging.
Return procedure for MPLAD18KP33A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MPLAD18KP33A Tags
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