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Microchip Technology MAPLAD18KP40A
- Part No.:
- MAPLAD18KP40A
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MAPLAD18KP40A.pdf
- Description:
- TVS DIODE 40VWM 64.5VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:2,485
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Product details
Overview
MAPLAD18KP40A from Microsemi is a surface-mount unidirectional 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 ≤64.5 V under 280 A peak impulse current, and features a 40 V reverse standoff voltage (VWM) with 44.4–49.1 V breakdown range. It is widely deployed in aircraft lightning protection per RTCA DO-160 Section 22.
For engineers reviewing the MAPLAD18KP40A datasheet, MAPLAD18KP40A pinout, MAPLAD18KP40A application, or MAPLAD18KP40A equivalent, key selection criteria include its 0.7 °C/W junction-to-case thermal resistance, 50 °C/W junction-to-ambient rating on FR4, RoHS-compliant e3 plating, and verified compliance with IEC 61000-4-2/4-4/4-5 and RTCA DO-160F Waveform 4 & 5A pin injection levels.
Technical Context
The MAPLAD18KP40A employs an avalanche diode structure optimized for low clamping ratio and fast response (<100 ps rise time), enabling effective suppression of multi-stroke lightning transients and load dump events. Its metal-base cathode construction provides direct thermal path to PCB copper, supporting high-reliability mounting on heat-sinked FR4 layouts.
It operates across –55°C to +150°C junction temperature range and meets AEC-Q101 stress testing requirements. Standby leakage is limited to 10 μA at 40 V, and it sustains 1500 A forward surge current (IFSM) with 2.0 V forward clamping at 500 A - critical for protecting downstream MOSFETs and gate drivers during sustained overvoltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (PPP) | 18,000 W @ 10/1000 μs - enables single-device protection against severe lightning surges without parallel staging |
| Reverse Standoff Voltage (VWM) | 40 V - matches nominal 36 V automotive and avionics bus systems while allowing margin for ripple and transients |
| Clamping Voltage (VC) | ≤64.5 V @ 280 A - ensures protected circuitry remains below 65 V absolute maximum during worst-case surge |
| Breakdown Voltage (V(BR)) | 44.4–49.1 V @ I(BR) - defines reliable avalanche initiation threshold with tight 10% tolerance band |
| Junction-to-Case Thermal Resistance | 0.7 °C/W - allows efficient heat transfer to PCB copper pour or heatsink, essential for repeated surge duty |
| Standby Leakage Current (ID) | ≤10 μA @ 40 V - minimizes quiescent power loss in always-on avionics and battery-backed systems |
| Surge Withstand (IEC 61000-4-5) | Class 4 @ 42 Ω source impedance - certifies secondary lightning protection capability for airborne equipment |
Pinout & Package
MAPLAD18KP40A uses a surface-mount plastic package with metal base cathode termination. The device has two terminals: anode (top-side marked side) and cathode (unmarked metal base). Mounting requires recommended 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 (e.g., 36 V bus); conducts only during positive overvoltage events |
| Cathode | Ground-reference terminal (metal base) | Soldered directly to large copper area or heatsink; serves as primary thermal and electrical return path |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SMT package | 0.470″ × 0.230″ × 0.100″ (11.94 × 5.85 × 2.44 mm) - enables compact placement near connectors and power entry points |
| RoHS-compliant matte-tin plating | e3 marking - ensures lead-free solder compatibility and long-term intermetallic stability per MIL-STD-750 |
| RTCA DO-160F Waveform 4 & 5A compliance | Level 4 up to 40 V devices - validates pin-injection immunity for aircraft wiring harnesses and backplane interfaces |
| Moisture Sensitivity Level 1 | No dry pack required - eliminates baking step and reduces assembly cost and risk of popcorning |
| AEC-Q101 qualified | Stress-tested per automotive reliability standard - supports use in engine control, ADAS, and cockpit electronics |
Applications
| Aircraft Lightning Protection | Automotive Load Dump Suppression |
|---|---|
Use Scenario: Protecting avionics power inputs from multi-stroke lightning-induced transients per RTCA DO-160 Section 22. IC Role / Device Role / Timing Role: Primary clamping element placed at power entry point to divert >15 kA surges before reaching DC-DC converters and FPGAs. Use Value: Enables single-device compliance with Level 4 pin injection (Waveform 4) and Class 4 secondary lightning (IEC 61000-4-5), reducing board space vs. stacked TVS arrays. | Use Scenario: Safeguarding 12 V/24 V/36 V vehicle ECUs during alternator load dump events (ISO 7637-2 Pulse 5a). IC Role / Device Role / Timing Role: Unidirectional shunt clamp on main power rail, triggered within <100 ps to limit bus voltage to ≤65 V. Use Value: Withstands 1500 A IFSM and 18 kW PPP, eliminating need for external fusing or derating in high-current chassis designs. |
| Industrial DC Power Distribution | Railway Signaling Interface Protection |
Use Scenario: Securing 48 V telecom and industrial power supplies against switching transients and EFT bursts. IC Role / Device Role / Timing Role: Front-end transient suppressor on rectified AC/DC output or PoE++ PSE outputs. Use Value: 10 μA ID at 40 V ensures minimal standby drain in energy-sensitive remote nodes; 50 °C/W RθJA supports operation on standard FR4 without heatsinks. | Use Scenario: Hardening 72 V/110 V signaling lines in EN 50121-3-2 compliant railway control cabinets against ESD and surge coupling. IC Role / Device Role / Timing Role: Bidirectional-capable variant anchor (MAPLAD18KP40CA) used in differential pair protection; unidirectional MAPLAD18KP40A applied to supply rails. Use Value: Validated for IEC 61000-4-2 (±15 kV air), -4-4 (±4 kV), and -4-5 (Class 4, 42 Ω), meeting full EMC immunity requirements without additional filtering. |
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 SMAJ40A | 600 W PPP rating, 5.0 mm × 3.5 mm SMA package, 64.5 V VC @ 57.1 A | Lower energy handling; suitable only for consumer-grade or non-safety-critical 40 V circuits | Select when cost sensitivity outweighs aerospace/automotive reliability requirements and surge energy stays below 1 kJ |
| Vishay SM8S40A | 6600 W PPP, 8.2 mm × 6.2 mm DO-218AB package, 64.5 V VC @ 102 A | Mid-tier power rating; lacks RTCA DO-160F validation and AEC-Q101 qualification | Choose for industrial controls where 6.6 kW surge capacity suffices and DO-160 compliance is not mandated |
Compared with SMAJ40A and SM8S40A, the MAPLAD18KP40A delivers 3× and 2.7× higher peak pulse power respectively, includes full aerospace qualification (DO-160F, AEC-Q101), and offers superior thermal performance via metal-base mounting - making it the only option for certified airborne and high-reliability automotive power rail protection.
Availability
MAPLAD18KP40A is available at Aetrix Electronics and suitable for aircraft lightning protection, automotive load dump suppression, and industrial DC power distribution requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for MAPLAD18KP40A 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 power management solutions for aerospace, defense, and industrial markets.
The MAPLAD18KP40A belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for mission-critical surge environments where multi-kilowatt transient energy, thermal robustness, and certification compliance are mandatory.
FAQ
What is the clamping voltage of MAPLAD18KP40A at its rated peak pulse current?
The MAPLAD18KP40A has a maximum clamping voltage (VC) of 64.5 V at 280 A peak pulse current (IPP) under 10/1000 μs waveform conditions. This value is guaranteed per datasheet Figure 3 and Table on page 4 of RF01215 Rev B. The clamping performance ensures protected downstream components remain within safe operating voltage limits during severe transients. MAPLAD18KP40A maintains this specification across its full operating temperature range.
Is MAPLAD18KP40A RoHS compliant and what does the 'e3' marking indicate?
Yes, MAPLAD18KP40A is RoHS compliant, indicated by the 'e3' suffix in its full part marking per Microsemi's nomenclature guide. The 'e3' denotes annealed matte-tin plating that meets JEDEC J-STD-020B Level 1 moisture sensitivity and is fully compatible with lead-free reflow processes. MAPLAD18KP40A requires no dry-pack handling and supports standard SMT assembly without baking. This compliance is verified in the Mechanical and Packaging section of RF01215 Rev B.
Does MAPLAD18KP40A meet AEC-Q101 qualification requirements?
Yes, MAPLAD18KP40A is tested and qualified to AEC-Q101 standards for discrete semiconductors, as explicitly stated in the "High-Reliability screening available" banner on page 1 of RF01215 Rev B. This qualification covers stress tests including HTGB, HTRB, TST, and mechanical shock - confirming suitability for automotive powertrain and safety-critical electronics. MAPLAD18KP40A's qualification supports its use in engine control units and ADAS power domains.
What is the thermal resistance profile of MAPLAD18KP40A and how does it impact PCB layout?
MAPLAD18KP40A has a junction-to-case thermal resistance (RθJC) of 0.7 °C/W and junction-to-ambient (RθJA) of 50 °C/W when mounted on FR4 with the recommended pad layout. The metal base serves as the primary thermal path, so PCB layout must include a large, thermally robust copper pour connected to the cathode terminal. MAPLAD18KP40A's low RθJC enables effective heat dissipation during repetitive surge events - critical for applications like aircraft lightning protection where multi-stroke capability is required.
Can MAPLAD18KP40A be used for bidirectional transient suppression?
No, MAPLAD18KP40A is a unidirectional TVS diode. For bidirectional protection at 40 V standoff, the correct variant is MAPLAD18KP40CA (with 'CA' suffix), which features symmetrical breakdown in both polarities. The 'A' suffix in MAPLAD18KP40A explicitly denotes unidirectional construction, and its cathode is the metal base - a configuration incompatible with reverse-polarity surge conduction. Using MAPLAD18KP40A in bidirectional applications risks catastrophic failure during negative transients.
MAPLAD18KP40A 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 280A
- 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
MAPLAD18KP40A FAQ
1.How can I place an order for MAPLAD18KP40A through Aetrix?
Please submit a Request for Quotation (RFQ) for MAPLAD18KP40A 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 MAPLAD18KP40A reliable?
The price and inventory of MAPLAD18KP40A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAPLAD18KP40A is usually 5 days.
3.What payment methods are accepted for MAPLAD18KP40A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAPLAD18KP40A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAPLAD18KP40A?
MAPLAD18KP40A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAPLAD18KP40A 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 MAPLAD18KP40A?
For technical support, including MAPLAD18KP40A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAPLAD18KP40A requirements.
6.How does Aetrix verify that MAPLAD18KP40A is sourced from the original manufacturer or authorized distributors?
All MAPLAD18KP40A 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 MAPLAD18KP40A meets industry standards.
7.What is the process for return or replacement of MAPLAD18KP40A?
All MAPLAD18KP40A units undergo pre-shipment inspection (PSI). If there is an issue with MAPLAD18KP40A, 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 MAPLAD18KP40A part is unused and in its original packaging.
Return procedure for MAPLAD18KP40A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAPLAD18KP40A Tags
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