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Microchip Technology MAPLAD18KP51A
- Part No.:
- MAPLAD18KP51A
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MAPLAD18KP51A.pdf
- Description:
- TVS DIODE 51VWM 82.4VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:6,869
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Product details
Overview
MAPLAD18KP51A from Microsemi is a surface-mount, unidirectional transient voltage suppressor (TVS) rated for 18,000 W peak pulse power at 10/1000 μs, with 51 V reverse standoff voltage (VWM), 56.7–62.7 V breakdown voltage (V(BR)), and 82.4 V maximum clamping voltage (VC) at 219 A peak pulse current. It delivers high-reliability lightning and load dump protection in aerospace avionics per RTCA DO-160F Waveform 4 Level 4.
For engineers reviewing the MAPLAD18KP51A datasheet, MAPLAD18KP51A pinout, MAPLAD18KP51A application, or MAPLAD18KP51A equivalent, key selection considerations include its 51 V VWM rating, 0.7 °C/W junction-to-case thermal resistance, RoHS-compliant e3 plating, MIL-PRF-19500 upscreening capability, and compliance with IEC 61000-4-2/4-4/4-5 and RTCA DO-160F surge immunity standards.
Technical Context
The MAPLAD18KP51A employs an avalanche diode structure optimized for high-energy transients, with clamping response under 100 ps and low thermal resistance enabling rapid heat dissipation to the PCB copper pad. Its metal-base cathode construction provides direct thermal path to heatsink-mounted layouts.
It meets secondary lightning protection requirements per IEC 61000-4-5 at 42 Ω, 12 Ω, and 2 Ω source impedances (Class 1–5 depending on configuration), and satisfies RTCA DO-160F pin injection immunity for Waveform 4 (6.4/69 μs) and Waveform 5A (40/120 μs) up to Level 4 and Level 5 respectively.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous DC or peak AC operating voltage before clamping initiates |
| V(BR) min/max | 56.7–62.7 V @ I(BR) - Ensures reliable breakdown onset within defined tolerance band |
| VC @ IPP | 82.4 V @ 219 A - Clamping voltage during 10/1000 μs surge, limiting downstream voltage stress |
| PPP | 18,000 W @ 10/1000 μs - Peak power handling capacity for multi-stroke lightning events |
| RθJC | 0.7 °C/W - Enables effective thermal coupling to heatsink or large copper pour for sustained surge duty |
| ID @ VWM | 10 μA max - Low leakage preserves system standby power integrity |
| αV(BR) | 60 mV/°C - Predictable temperature drift supports stable clamping across -55°C to +150°C |
Pinout & Package
MAPLAD18KP51A uses a surface-mount plastic package with metal base cathode terminal. The device has two terminals: anode (top-side marked side) and cathode (unmarked metal bottom surface). Mounting requires recommended FR4 pad layout per RF01215 Rev B for optimal thermal and mechanical reliability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive input terminal for unidirectional surge conduction | Connected to protected line; conducts surge current toward cathode when voltage exceeds V(BR) |
| Cathode | Ground reference / return path (metal base) | Serves as primary thermal interface and low-inductance return path; must be soldered to large copper area or heatsink |
Key Features
| Feature | Design Value |
|---|---|
| 18 kW peak pulse rating | Supports multi-stroke lightning testing per RTCA DO-160 Section 22 without degradation |
| Metal-base thermal design | 0.7 °C/W RθJC enables >71 W steady-state dissipation at TC = 100°C with proper heatsinking |
| RoHS-compliant e3 plating | Tin-lead alternative not required; compatible with lead-free reflow profiles up to 260°C for 10 s |
| AEC-Q101 qualified | Validated for automotive-grade reliability including HTOL, temperature cycling, and surge endurance |
| Level 1 moisture sensitivity | No dry-pack or baking required prior to assembly per IPC/JEDEC J-STD-020B |
Applications
| Aerospace Avionics Power Input | Automotive Engine Control Unit (ECU) |
|---|---|
Use Scenario: Protection of 28 V DC aircraft power bus against lightning-induced surges per RTCA DO-160F Waveform 4 Level 4. IC Role / Device Role / Timing Role: Primary transient suppression device placed at main power entry point before DC-DC converters. Use Value: Limits clamped voltage to ≤82.4 V during 6.4/69 μs transients, preserving downstream 100 V-rated MOSFETs and controllers. | Use Scenario: Load dump protection on 12 V battery-fed ECU supply rail during alternator regulation failure. IC Role / Device Role / Timing Role: Unidirectional TVS absorbing 18 kW pulses generated by inductive energy release. Use Value: Withstands ≥1000 surge cycles at 10/1000 μs while maintaining VWM stability and low leakage (<10 μA). |
| Industrial Motor Drive DC Bus | Railway Signaling Interface |
Use Scenario: Secondary surge protection on 48 V DC bus feeding servo drives in factory automation systems. IC Role / Device Role / Timing Role: High-power clamping element placed after upstream MOVs to handle residual fast-rising transients. Use Value: 82.4 V clamping ensures IGBT gate drivers remain below absolute maximum ratings during IEC 61000-4-5 42 Ω Class 4 events. | Use Scenario: Protection of 51 V signaling lines in EN 50121-compliant railway control cabinets against EFT and lightning coupling. IC Role / Device Role / Timing Role: Bidirectional-capable variant (MAPLAD18KP51CA) used for AC-coupled data lines; unidirectional MAPLAD18KP51A applied to DC bias rails. Use Value: 60 mV/°C αV(BR) ensures predictable clamping shift over -40°C to +85°C operating range, critical for safety-critical signaling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51A | 600 W PPP rating, SMC package, 0.5 A IPP max, higher RθJA (50 °C/W) | Limited to single-stroke or low-duty-cycle surges; unsuitable for RTCA DO-160 multi-stroke validation | Select SMBJ51A only for cost-sensitive consumer applications where 18 kW capability is unnecessary |
| SMCJ51A | 1500 W PPP rating, same SMC package footprint, 125 A IPP, RθJC ≈ 1.5 °C/W | Meets IEC 61000-4-5 Class 3 but fails DO-160F Level 4 waveform compliance | Choose SMCJ51A for industrial controls requiring moderate surge margin but no aerospace qualification |
Compared with SMBJ51A and SMCJ51A, the MAPLAD18KP51A delivers 12× and 12× higher peak pulse power respectively, with superior thermal coupling (0.7 vs. ≥1.5 °C/W) and full DO-160F Level 4 validation-making it the only option for certified avionics power entry protection.
Availability
MAPLAD18KP51A is available at Aetrix Electronics and suitable for aerospace avionics, automotive ECU, industrial motor drive, and railway signaling applications requiring stable component supply, long-term lifecycle support, and traceable high-reliability sourcing.
Supply support for MAPLAD18KP51A 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) designs high-reliability analog, mixed-signal, and power semiconductors for aerospace, defense, and industrial markets.
The MAPLAD18KP51A belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for multi-stroke lightning immunity and automotive load dump survival in mission-critical systems.
FAQ
What is the clamping voltage of MAPLAD18KP51A at its rated peak pulse current?
The MAPLAD18KP51A has a maximum clamping voltage (VC) of 82.4 V at 219 A peak pulse current (IPP) under 10/1000 μs waveform conditions. This value is guaranteed per RF01215 Rev B and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The clamping occurs within <100 ps, ensuring minimal overvoltage exposure to downstream components.
Does MAPLAD18KP51A meet RTCA DO-160F lightning test requirements?
Yes, MAPLAD18KP51A is validated for RTCA DO-160F Section 22 lightning-induced transient testing, specifically Waveform 4 (6.4/69 μs) at Level 4. Its 18,000 W peak pulse power rating, low RθJC (0.7 °C/W), and controlled V(BR) tolerance (56.7–62.7 V) ensure consistent multi-stroke performance without parametric shift or failure across temperature and life cycle.
Is MAPLAD18KP51A RoHS compliant and what plating does it use?
Yes, MAPLAD18KP51A is RoHS compliant and carries the "e3" designation indicating annealed matte-tin plating per MIL-STD-750 Method 2026. This finish supports lead-free reflow soldering up to 260°C for 10 seconds and eliminates tin whisker risk, making it suitable for high-reliability aerospace and automotive assemblies where intermetallic growth and solder joint integrity are critical.
What is the thermal resistance and how should MAPLAD18KP51A be mounted for optimal cooling?
MAPLAD18KP51A has a junction-to-case thermal resistance (RθJC) of 0.7 °C/W. For optimal cooling, the metal base (cathode) must be soldered to a minimum 1.0 in² (645 mm²) copper pad on FR4, using the pad layout specified in RF01215 Rev B. Thermal vias under the pad and connection to internal ground planes further reduce effective RθJA, supporting sustained operation at up to 71 W at TC = 100°C.
Can MAPLAD18KP51A be used in bidirectional configurations?
No-MAPLAD18KP51A is unidirectional. For bidirectional operation, the functionally matched part is MAPLAD18KP51CA, which shares identical VWM (51 V), PPP (18,000 W), and thermal specs but adds symmetrical clamping for AC or floating-line protection. The "A" suffix denotes unidirectional polarity; "CA" indicates bidirectional construction with center-tapped or dual-anode geometry.
MAPLAD18KP51A 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 219A
- 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
MAPLAD18KP51A FAQ
1.How can I place an order for MAPLAD18KP51A through Aetrix?
Please submit a Request for Quotation (RFQ) for MAPLAD18KP51A 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 MAPLAD18KP51A reliable?
The price and inventory of MAPLAD18KP51A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAPLAD18KP51A is usually 5 days.
3.What payment methods are accepted for MAPLAD18KP51A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAPLAD18KP51A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAPLAD18KP51A?
MAPLAD18KP51A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAPLAD18KP51A 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 MAPLAD18KP51A?
For technical support, including MAPLAD18KP51A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAPLAD18KP51A requirements.
6.How does Aetrix verify that MAPLAD18KP51A is sourced from the original manufacturer or authorized distributors?
All MAPLAD18KP51A 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 MAPLAD18KP51A meets industry standards.
7.What is the process for return or replacement of MAPLAD18KP51A?
All MAPLAD18KP51A units undergo pre-shipment inspection (PSI). If there is an issue with MAPLAD18KP51A, 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 MAPLAD18KP51A part is unused and in its original packaging.
Return procedure for MAPLAD18KP51A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAPLAD18KP51A Tags
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