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Microchip Technology MAPLAD18KP45A
- Part No.:
- MAPLAD18KP45A
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MAPLAD18KP45A.pdf
- Description:
- TVS DIODE 45VWM 72.7VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:4,591
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Product details
Overview
MAPLAD18KP45A 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 ≤72.7 V under 248 A peak impulse current, and features a 45 V reverse standoff voltage (VWM) with 50–55.3 V breakdown range. It is qualified to AEC-Q101 and meets RTCA DO-160F Level 4 pin injection for waveform 4.
For engineers reviewing the MAPLAD18KP45A datasheet, MAPLAD18KP45A pinout, MAPLAD18KP45A application, or MAPLAD18KP45A equivalent, this device is selected for secondary lightning protection per IEC 61000-4-5 (42 Ω, 12 Ω, and 2 Ω source impedances), ESD/EFT immunity per IEC 61000-4-2/4-4, and load dump suppression in 24 V/48 V vehicle subsystems.
Technical Context
The MAPLAD18KP45A employs an avalanche diode structure optimized for low clamping ratio and minimal thermal resistance (RθJC = 0.7 °C/W). Its metal-base package enables direct heatsinking, supporting sustained surge duty cycles ≤0.05% at ambient temperatures up to +150 °C junction.
It operates as a unidirectional crowbar device-conducting only during reverse overvoltage events-with cathode on the metal base. Standby leakage is limited to 10 μA at 45 V, and forward clamping remains ≤2.0 V at 500 A, enabling robust protection without interfering with normal forward-biased circuit operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 μs) | 18,000 W - sustains multi-stroke lightning surges per RTCA DO-160 Section 22 without degradation |
| Reverse Standoff Voltage (VWM) | 45 V - matches nominal 48 V DC bus systems while allowing margin above operating peak |
| Breakdown Voltage (V(BR)) | 50.0–55.3 V @ I(BR) - ensures reliable triggering before downstream component damage thresholds |
| Max Clamping Voltage (VC) | 72.7 V @ 248 A - limits protected circuit voltage to safe levels during worst-case transients |
| Thermal Resistance (Junction-to-Case) | 0.7 °C/W - enables efficient heat transfer to PCB copper or external heatsink for repeated surge handling |
| Standby Leakage Current (ID) | 10 μA @ 45 V - negligible power loss in always-on 24/48 V systems such as avionics power rails |
| Junction Temperature Range | −55 to +150 °C - supports operation in engine bay, flight control, and outdoor industrial enclosures |
Pinout & Package
MAPLAD18KP45A uses a proprietary surface-mount plastic package with metal base (cathode) and top-side anode terminal. The case is void-free thermosetting epoxy (UL94V-0), with matte-tin plating for solderability. Dimensions: 12.32 × 10.54 × 5.33 mm (L × W × H).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (top surface) | Positive input node for reverse-biased protection path | Connected to protected line (e.g., 48 V rail); conducts only during overvoltage |
| Cathode (metal base) | Ground reference / return path | Must be soldered to large copper pour or heatsink; serves as primary thermal and electrical return |
Key Features
| Feature | Design Value |
|---|---|
| 18 kW surge rating | Validated for ≥1000 surges at 248 A (10/1000 μs), meeting RTCA DO-160F multi-stroke requirements |
| Low RθJC (0.7 °C/W) | Enables >2× higher surge repetition rate vs. standard SMD TVS when mounted on 2 oz copper |
| AEC-Q101 qualified | Guarantees reliability for automotive powertrain and chassis modules without additional qualification effort |
| RoHS-compliant (e3) | Meets global environmental compliance without lead-based solder compatibility compromises |
| IEC 61000-4-5 Class 4 support (42 Ω) | Provides secondary lightning protection for avionics data buses and sensor interfaces |
Applications
| Aerospace Power Distribution | Commercial Vehicle DC Bus Protection |
|---|---|
Use Scenario: 28 V and 48 V primary distribution panels in regional aircraft, where load dump and lightning-induced transients exceed 10 kA. IC Role / Device Role / Timing Role: Unidirectional TVS placed upstream of DC-DC converters and motor controllers to clamp surges before they propagate. Use Value: Prevents latch-up or gate oxide rupture in downstream SiC MOSFETs by limiting voltage to ≤72.7 V during 10/1000 μs transients. |
Use Scenario: 48 V mild-hybrid battery management systems exposed to ISO 7637-2 Pulse 5a (load dump) up to 60 V. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main battery feed, coordinated with upstream fusing. Use Value: Absorbs 18 kW pulses without failure, eliminating need for bulky discrete MOV+gas tube stacks in space-constrained modules. |
| Industrial Motor Drive Inputs | Railway Signaling Interface |
Use Scenario: AC/DC front-end rectifiers in servo drives subjected to switching transients and induced RFI from nearby IGBTs. IC Role / Device Role / Timing Role: Fast-response TVS across DC link inputs to suppress dV/dt spikes exceeding 100 V/μs. Use Value: Clamps within <100 ps, preventing false triggering of overvoltage protection circuits and reducing system downtime. |
Use Scenario: 72 V signaling lines in European railway ETCS Level 2 balises, requiring IEC 61000-4-5 Class 3 (42 Ω) immunity. IC Role / Device Role / Timing Role: Secondary protection stage after gas discharge tube (GDT), handling residual energy post-GDT conduction. Use Value: Delivers precise clamping at 72.7 V to protect RS-485 transceivers rated for 80 V absolute max, avoiding latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ45A | 600 W rating, 1.5× higher clamping voltage (110 V), TO-263 package with higher RθJA (55 °C/W) | Limited to single-stroke surges; unsuitable for RTCA DO-160 multi-stroke or repeated load dump | Select only for cost-sensitive, low-duty-cycle consumer-grade 48 V systems |
| SMCJ45A | 1500 W rating, same VWM but 93.6 V clamping at 132 A, larger SMC package with RθJC = 1.5 °C/W | Cannot meet 18 kW requirement; requires parallel devices for equivalent energy handling | Use only when board space allows multiple devices and thermal design accommodates higher junction rise |
Compared with SMBJ45A and SMCJ45A, MAPLAD18KP45A provides 30× higher pulse power density, 35% lower clamping voltage, and integrated thermal path-enabling single-device protection in aerospace and heavy-duty automotive where footprint, reliability, and multi-event survivability are critical.
Availability
MAPLAD18KP45A is available at Aetrix Electronics and suitable for aerospace power distribution, commercial vehicle DC bus protection, and industrial motor drive inputs requiring stable component supply across extended product lifecycles.
Supply support for MAPLAD18KP45A 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 (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and timing solutions for aerospace, defense, and industrial markets.
The MAPLAD18KP45A belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for multi-stroke lightning and load dump protection in safety-critical platforms where failure is not an option.
FAQ
What is the maximum peak pulse current the MAPLAD18KP45A can handle?
The MAPLAD18KP45A is rated for 248 A peak impulse current at the standard 10/1000 μs waveform. This value is derived directly from its 18,000 W peak pulse power rating and 72.7 V clamping voltage (PPP = VC × IPP). It is validated per IEC 61000-4-5 and RTCA DO-160F test conditions, with full surge testing performed on every production lot.
Is MAPLAD18KP45A suitable for bidirectional signal line protection?
No - MAPLAD18KP45A is a unidirectional TVS diode, with polarity marked by cathode on the metal base. For bidirectional protection, the equivalent part is MAPLAD18KP45CA. Using MAPLAD18KP45A on AC or differential signal lines risks forward conduction and permanent damage during normal operation.
Does MAPLAD18KP45A require derating at elevated ambient temperatures?
Yes - the MAPLAD18KP45A must be derated above 25 °C ambient. Its peak pulse power drops linearly to zero at 150 °C junction temperature, with a defined derating curve in Figure 3 of RF01215 Rev B. At 100 °C case temperature, PPP is reduced to ~71 W for steady-state dissipation, but pulsed capability remains governed by thermal mass and RθJC.
Can MAPLAD18KP45A be used without a heatsink in a standard FR4 PCB layout?
Yes - MAPLAD18KP45A is qualified for operation on FR4 with the recommended pad layout (per RF01215 Rev B, Page 7), delivering RθJA = 50 °C/W. However, for repeated surges or high ambient environments, attaching the metal base to an internal copper plane or external heatsink is strongly advised to maintain junction temperature below 150 °C.
What certifications does MAPLAD18KP45A hold beyond AEC-Q101?
MAPLAD18KP45A is tested to IEC 61000-4-2 (ESD ±30 kV air), IEC 61000-4-4 (EFT 4 kV), and IEC 61000-4-5 (lightning, 42 Ω/12 Ω/2 Ω source). It also meets RTCA DO-160F Section 22 (lightning) and Waveform 4/5A pin injection (Levels 4–5), and carries RoHS compliance (e3 marking). MIL-PRF-19500 upscreening is optional but not standard.
MAPLAD18KP45A 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 248A
- 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
MAPLAD18KP45A FAQ
1.How can I place an order for MAPLAD18KP45A through Aetrix?
Please submit a Request for Quotation (RFQ) for MAPLAD18KP45A 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 MAPLAD18KP45A reliable?
The price and inventory of MAPLAD18KP45A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAPLAD18KP45A is usually 5 days.
3.What payment methods are accepted for MAPLAD18KP45A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAPLAD18KP45A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAPLAD18KP45A?
MAPLAD18KP45A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAPLAD18KP45A 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 MAPLAD18KP45A?
For technical support, including MAPLAD18KP45A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAPLAD18KP45A requirements.
6.How does Aetrix verify that MAPLAD18KP45A is sourced from the original manufacturer or authorized distributors?
All MAPLAD18KP45A 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 MAPLAD18KP45A meets industry standards.
7.What is the process for return or replacement of MAPLAD18KP45A?
All MAPLAD18KP45A units undergo pre-shipment inspection (PSI). If there is an issue with MAPLAD18KP45A, 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 MAPLAD18KP45A part is unused and in its original packaging.
Return procedure for MAPLAD18KP45A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAPLAD18KP45A Tags
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