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Microchip Technology MAPLAD18KP78CA
- Part No.:
- MAPLAD18KP78CA
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MAPLAD18KP78CA.pdf
- Description:
- TVS DIODE 78VWM 126VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:5,421
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Product details
Overview
MAPLAD18KP78CA from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace and automotive systems. It delivers 18,000 W peak pulse power at 10/1000 μs, features a 78 V reverse standoff voltage (VWM), clamps to ≤126 V at 143 A peak impulse current, and meets RTCA DO-160 Section 22 multi-stroke lightning requirements.
For engineers reviewing the MAPLAD18KP78CA datasheet, MAPLAD18KP78CA pinout, MAPLAD18KP78CA application, or MAPLAD18KP78CA equivalent, this device is selected for secondary lightning protection per IEC 61000-4-5 (42 Ω, 12 Ω, and 2 Ω source impedances), pin-injection protection per RTCA/DO-160F Waveform 4 Level 4, and ESD/EFT immunity per IEC 61000-4-2/4-4.
Technical Context
The MAPLAD18KP78CA employs an avalanche diode structure optimized for low clamping ratio and minimal thermal resistance (RθJC = 0.7 °C/W). Its bidirectional construction enables symmetrical transient suppression across both polarities without external polarity management.
It operates within -55°C to +150°C junction temperature range and maintains stable breakdown voltage (V(BR) = 86.7–95.8 V @ I(BR)) with ±5% tolerance and 94 mV/°C temperature coefficient. Standby leakage is limited to 10 μA at 78 V, supporting low-power system monitoring integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 18,000 W @ 10/1000 μs - sustains aircraft-grade lightning surges without failure |
| Reverse Standoff Voltage (VWM) | 78 V - matches nominal 72 V DC bus systems with margin for transients |
| Clamping Voltage (VC) | ≤126 V @ IPP = 143 A - limits downstream IC stress below 130 V absolute max |
| Breakdown Voltage (V(BR)) | 86.7–95.8 V @ I(BR) - ensures reliable turn-on before system overvoltage damage |
| Thermal Resistance (Junction-to-Case) | 0.7 °C/W - enables direct heatsink mounting for sustained multi-pulse operation |
| Leakage Current (ID) | ≤10 μA @ 78 V - preserves battery-backed circuit integrity in always-on avionics |
| Surge Rating Standard | RTCA DO-160F Waveform 4 Level 4 & IEC 61000-4-5 Class 1–5 - certified for airborne equipment zones |
Pinout & Package
MAPLAD18KP78CA uses a low-profile surface-mount PLAD package with metal base cathode contact on the underside. The device has two terminals: anode and cathode, with polarity marked by cathode location on the metal backside.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry point (bidirectional) | Accepts positive or negative surge energy; connects to protected line |
| Cathode | Transient current return path (metal base) | Must be soldered to large copper pour or heatsink for thermal and electrical performance |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional surge suppression | Eliminates need for dual unidirectional devices or external polarity logic in AC-coupled or floating systems |
| 0.7 °C/W RθJC | Enables >1000 pulses at 0.05% duty cycle without thermal runaway when mounted per recommended pad layout |
| RTCA DO-160F Waveform 4 Level 4 compliance | Validated for pin-injection transients up to 6.4/69 μs on flight-critical data buses |
| IEC 61000-4-5 Class 1–5 support (42 Ω source) | Meets full secondary lightning protection requirements for commercial aircraft avionics bays |
| MIL-PRF-19500 upscreening option | Supports high-reliability screening (M, MA, MX, MXL levels) for mission-critical aerospace deployments |
Applications
| Avionics Power Distribution | Aerospace Data Bus Protection |
|---|---|
Use Scenario: Protecting 28 V DC power feeds to flight control computers and sensors against load dump and lightning-induced surges. IC Role / Device Role / Timing Role: Primary transient clamp on main power rail, operating in parallel with upstream fuses and downstream DC-DC converters. Use Value: Limits rail voltage to ≤126 V during 18 kW surges, preventing latch-up or burnout of 100 V-rated power MOSFETs and microcontrollers. | Use Scenario: Shielding ARINC 429 or MIL-STD-1553B data lines from induced RFI and pin-injection transients in wing-mounted electronics. IC Role / Device Role / Timing Role: Bidirectional TVS placed differential across signal pair, referenced to chassis ground via low-inductance path. Use Value: Clamps fast transients (<100 ps response) while preserving signal integrity up to 1 MHz due to low capacitance and symmetric clamping. |
| Automotive Engine Control Unit (ECU) | Railway Signaling Interface |
Use Scenario: Safeguarding 12 V/24 V ECU inputs against ISO 7637-2 load dump and ISO 16750-2 supply transients in diesel engine compartments. IC Role / Device Role / Timing Role: Secondary protection stage after front-end LC filters, directly mounted at connector entry point. Use Value: Absorbs 18 kW surges without degradation, maintaining <10 μA leakage to avoid false wake-up in sleep-mode ECUs. | Use Scenario: Protecting track-side signaling interfaces (e.g., ETCS Level 1 balise readers) from lightning-induced ground potential rise in outdoor cabinets. IC Role / Device Role / Timing Role: Bidirectional TVS bridging signal line to protective earth, rated for IEC 61000-4-5 Class 4 (2 Ω source). Use Value: Survives repeated 4 kV surges with no parameter shift, verified per AEC-Q101 and extended temperature cycling (-55°C to +150°C). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CA | 600 W PPP rating, SMC package, RθJC ≈ 12 °C/W | Not suitable for RTCA DO-160F Level 4 or multi-stroke lightning; limited to consumer/industrial use | Select only for cost-sensitive non-aerospace designs where 18 kW surge capacity is unnecessary |
| SMCJ78CA | 1500 W PPP rating, larger SMC package, RθJC ≈ 5.5 °C/W | Lacks RTCA DO-160F Waveform 4 validation and MIL-PRF-19500 screening options | Use where moderate surge immunity suffices and board space allows larger footprint |
Compared with SMBJ78CA and SMCJ78CA, MAPLAD18KP78CA provides 30× higher peak pulse power, 8× lower thermal resistance, and formal certification for airborne lightning standards-making it irreplaceable in certified avionics and high-reliability transportation systems.
Availability
MAPLAD18KP78CA is available at Aetrix Electronics and suitable for avionics power distribution, aerospace data bus protection, and railway signaling interface applications requiring stable component supply across extended product lifecycles.
Supply support for MAPLAD18KP78CA 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 components for aerospace, defense, and industrial markets.
The MAPLAD18KP78CA belongs to Microsemi's high-power PLAD-series TVS family, engineered specifically for certified airborne systems requiring multi-stroke lightning resilience, low thermal impedance, and extended temperature operation.
FAQ
What is the clamping voltage of MAPLAD18KP78CA at its rated peak pulse current?
The MAPLAD18KP78CA has a maximum clamping voltage (VC) of 126 V at its rated peak impulse current (IPP) of 143 A under 10/1000 μs waveform conditions. This value is guaranteed per the manufacturer's electrical characteristics table and ensures downstream components see voltage limited to this threshold during surge events. The MAPLAD18KP78CA achieves this with low dynamic impedance and stable avalanche behavior across its operational temperature range.
Does MAPLAD18KP78CA meet RTCA DO-160F lightning test requirements?
Yes, MAPLAD18KP78CA is validated for RTCA DO-160F Section 22 multi-stroke lightning testing and specifically certified for Waveform 4 (6.4/69 μs) at Level 4. Its 18,000 W peak pulse power rating and low clamping ratio enable compliance with stringent aircraft equipment zone requirements. The MAPLAD18KP78CA data sheet explicitly lists this qualification, confirming suitability for flight-critical power and signal lines.
What is the thermal resistance junction-to-case for MAPLAD18KP78CA, and why does it matter?
The MAPLAD18KP78CA has a thermal resistance junction-to-case (RθJC) of 0.7 °C/W, measured per JEDEC JESD51-14. This ultra-low value enables efficient heat transfer from the silicon die to an external heatsink or PCB copper plane. For MAPLAD18KP78CA, this allows sustained multi-pulse operation (e.g., >1000 surges at 0.05% duty factor) without thermal runaway-critical for avionics systems exposed to repeated lightning transients.
Is MAPLAD18KP78CA RoHS compliant, and how is compliance indicated in the part number?
Yes, MAPLAD18KP78CA is RoHS compliant, indicated by the "e3" suffix in its full ordering code (e.g., MAPLAD18KP78CA-e3). The device uses annealed matte-tin plating on terminals and void-free UL94V-0 epoxy molding compound. RoHS compliance is verified per EU Directive 2011/65/EU and documented in Microsemi's material declarations. The MAPLAD18KP78CA meets lead-free soldering requirements up to 260°C for 10 seconds.
Can MAPLAD18KP78CA be used in bidirectional AC signal paths?
Yes, MAPLAD18KP78CA is a bidirectional TVS diode, making it suitable for AC-coupled or floating signal paths such as MIL-STD-1553B, ARINC 429, or isolated CAN transceivers. Its symmetrical breakdown and clamping behavior (V(BR) = 86.7–95.8 V in both directions) ensures equal protection against positive and negative transients. When applied in such paths, the MAPLAD18KP78CA must be mounted with its metal cathode base thermally and electrically connected to a low-inductance ground reference.
MAPLAD18KP78CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- Nonstandard SMD
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 143A
- 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
MAPLAD18KP78CA FAQ
1.How can I place an order for MAPLAD18KP78CA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAPLAD18KP78CA 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 MAPLAD18KP78CA reliable?
The price and inventory of MAPLAD18KP78CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAPLAD18KP78CA is usually 5 days.
3.What payment methods are accepted for MAPLAD18KP78CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAPLAD18KP78CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAPLAD18KP78CA?
MAPLAD18KP78CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAPLAD18KP78CA 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 MAPLAD18KP78CA?
For technical support, including MAPLAD18KP78CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAPLAD18KP78CA requirements.
6.How does Aetrix verify that MAPLAD18KP78CA is sourced from the original manufacturer or authorized distributors?
All MAPLAD18KP78CA 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 MAPLAD18KP78CA meets industry standards.
7.What is the process for return or replacement of MAPLAD18KP78CA?
All MAPLAD18KP78CA units undergo pre-shipment inspection (PSI). If there is an issue with MAPLAD18KP78CA, 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 MAPLAD18KP78CA part is unused and in its original packaging.
Return procedure for MAPLAD18KP78CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAPLAD18KP78CA Tags
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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