My Inquiry
My Account
Microchip Technology MAPLAD18KP28A
- Part No.:
- MAPLAD18KP28A
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- Nonstandard SMD
- Datasheet:
-
MAPLAD18KP28A.pdf
- Description:
- TVS DIODE 28VWM 45.5VC PLAD
- Quantity:
- Payment:
- Shipping:
Inventory:2,810
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAPLAD18KP28A 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 ≤45.5 V under 396 A peak impulse current, and features a 28 V reverse standoff voltage (VWM) with 31.1–34.4 V breakdown voltage (V(BR)). It is widely deployed in aircraft lightning protection per RTCA DO-160 Section 22.
For engineers reviewing the MAPLAD18KP28A datasheet, MAPLAD18KP28A pinout, MAPLAD18KP28A application, or MAPLAD18KP28A equivalent, key selection criteria include its 28 V working voltage rating, sub-100 ps response time, low thermal resistance (0.7 °C/W junction-to-case), RoHS-compliant e3 plating, and qualification to AEC-Q101 and MIL-PRF-19500 screening levels.
Technical Context
The MAPLAD18KP28A employs an avalanche diode structure optimized for multi-stroke lightning transients, with clamping performance validated under IEC 61000-4-5 (42 Ω, 12 Ω, and 2 Ω source impedances) and RTCA DO-160F Waveform 4 (Level 4) and Waveform 5A (Level 4). Its metal-base cathode construction enables direct thermal coupling to heatsinks.
It operates across –55 °C to +150 °C junction temperature range, supports steady-state dissipation of 2.5 W at 25 °C ambient (derated to 71 W at 100 °C case temperature), and exhibits a +0.03 %/°C temperature coefficient of breakdown voltage - enabling stable clamping over wide thermal excursions in avionics and engine control units.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 μs) | 18,000 W - sustains full-rated surge energy without degradation in multi-pulse lightning events |
| Reverse Standoff Voltage (VWM) | 28 V - maximum continuous DC or peak AC voltage before conduction begins |
| Breakdown Voltage (V(BR)) | 31.1–34.4 V @ I(BR) - ensures reliable avalanche initiation above operating bus voltage |
| Max Clamping Voltage (VC) | 45.5 V @ 396 A - limits downstream circuit voltage during worst-case surge |
| Junction-to-Case Thermal Resistance | 0.7 °C/W - enables efficient heat transfer to PCB copper or external heatsink |
| Standby Current (ID) | 10 μA @ 28 V - negligible leakage in standby, critical for low-power avionics monitoring circuits |
| Response Time | <100 ps - faster than most semiconductor switches, ensuring protection precedes device damage |
Pinout & Package
MAPLAD18KP28A uses a surface-mount plastic package with metal base (cathode) and single anode terminal on top. The metal base serves as the cathode connection and primary thermal path. Package dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H), with recommended FR4 pad layout per RF01215 Rev B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Metal Base (Bottom) | Cathode | Primary current return path and thermal interface - must be soldered to large copper pour or heatsink |
| Top Anode Pad | Anode | Transient current entry point - connects to protected line (e.g., 28 V aircraft bus) |
Key Features
| Feature | Design Value |
|---|---|
| 18 kW Surge Rating | Validated for ≥1000 surges at 396 A (10/1000 μs), meeting RTCA DO-160 Section 22 multi-stroke requirements |
| Low RθJC (0.7 °C/W) | Enables >70 W steady-state power handling at 100 °C case temp - supports hybrid surge + bias operation |
| AEC-Q101 Qualified | Passed stress tests including HTGB, HTRB, and temperature cycling - suitable for automotive engine bay applications |
| RoHS Compliant (e3) | Tin-plated terminals meet J-STD-020B Level 1 moisture sensitivity - no dry pack required pre-reflow |
| Pin Injection Protection | Rated Level 4 per RTCA DO-160F Waveform 4 (6.4/69 μs) - protects against induced transients on signal/power pins |
Applications
| Avionics Power Bus Protection | Automotive Load Dump Suppression |
|---|---|
Use Scenario: 28 V DC distribution bus in commercial aircraft experiencing repeated lightning-induced surges per DO-160 Section 22. IC Role / Device Role / Timing Role: Primary clamping device placed directly at bus entry point to limit transient voltage to <46 V. Use Value: Prevents latch-up or destruction of downstream DC-DC converters and flight control electronics during multi-stroke events. | Use Scenario: 12 V/24 V alternator output in heavy-duty trucks subjected to ISO 7637-2 Load Dump pulses up to 120 V. IC Role / Device Role / Timing Role: Unidirectional TVS shunting surge energy away from ECU power inputs during alternator field collapse. Use Value: Eliminates need for oversized input capacitors and extends ECU lifetime under harsh vehicle electrical environments. |
| Industrial Motor Drive DC Link | Railway Signaling Interface |
Use Scenario: DC link rail in variable-frequency drives exposed to IGBT switching transients and inductive kickback. IC Role / Device Role / Timing Role: Fast-response clamping element parallel to bulk electrolytic capacitor to absorb high-dI/dt spikes. Use Value: Reduces voltage overshoot by >35% versus MOV-only solutions, improving IGBT reliability and reducing snubber losses. | Use Scenario: 24 V signaling lines in European railway signaling cabinets subject to IEC 61000-4-5 surge testing (Class 4, 4 kV, 42 Ω source). IC Role / Device Role / Timing Role: Secondary protection stage after gas discharge tube, providing precise clamping below 46 V. Use Value: Ensures SIL-2 compliance by limiting transient overvoltage to safe levels for isolated RS-485 transceivers and safety relays. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ28A | 600 W rating (vs. 18,000 W); 400 A max IPP; TO-263 package with higher RθJA (50 °C/W) | Only suitable for single-event, low-energy transients - not rated for DO-160 multi-stroke or load dump | Select SMBJ28A only for cost-sensitive consumer-grade designs where surge energy is <10% of MAPLAD18KP28A capability |
| SMCJ28A | 1500 W rating; 100 A IPP; same SMC package but lower PPP and no AEC-Q101 or DO-160 qualification | Lacks multi-stroke validation and aviation-grade screening - limited to industrial controls without certification requirements | Choose SMCJ28A when full DO-160 compliance and 18 kW surge handling are not required |
Compared with SMBJ28A and SMCJ28A, MAPLAD18KP28A provides 30× higher peak power, certified multi-stroke endurance, and traceable lot-level screening - making it the only viable option for certified aerospace and high-reliability automotive power protection.
Availability
MAPLAD18KP28A is available at Aetrix Electronics and suitable for avionics power bus protection, automotive load dump suppression, and industrial motor drive DC link applications requiring stable component supply, long-term lifecycle support, and certified surge performance.
Supply support for MAPLAD18KP28A 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 ICs for aerospace, defense, and industrial markets.
The MAPLAD18KP28A belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for certified lightning and load dump protection in mission-critical systems where multi-stroke survivability and thermal robustness are mandatory.
FAQ
What is the clamping voltage of MAPLAD18KP28A at its rated peak pulse current?
The MAPLAD18KP28A has a maximum clamping voltage (VC) of 45.5 V at its rated peak pulse current of 396 A under 10/1000 μs waveform conditions. This value is guaranteed per the manufacturer's electrical characteristics table and ensures downstream components remain within safe operating voltage limits during surge events. The clamping performance is validated across temperature and production lots.
Is MAPLAD18KP28A qualified for automotive applications?
Yes, MAPLAD18KP28A is qualified to AEC-Q101 standards, including high-temperature reverse bias (HTRB), high-temperature gate bias (HTGB), and temperature cycling. It is explicitly rated for automotive load dump protection per ISO 7637-2 and supports under-hood deployment up to +150 °C junction temperature - making MAPLAD18KP28A suitable for engine control units and battery management systems.
Does MAPLAD18KP28A require special PCB layout considerations?
Yes, MAPLAD18KP28A requires a dedicated thermal pad layout per RF01215 Rev B: a minimum 12.32 × 10.54 mm copper area on the bottom layer, connected via multiple thermal vias to internal ground planes. The metal base (cathode) must be soldered directly to this pad to achieve the specified 0.7 °C/W junction-to-case thermal resistance. Narrow traces or insufficient copper will cause thermal runaway during repeated surges.
Can MAPLAD18KP28A be used for bidirectional protection?
No, MAPLAD18KP28A is unidirectional only. Its part number suffix "A" (not "CA") confirms unidirectional polarity. For bidirectional protection at 28 V standoff, the correct variant is MAPLAD18KP28CA. Using MAPLAD18KP28A on AC or bipolar lines will result in forward conduction and failure during negative half-cycles.
What certifications does MAPLAD18KP28A meet for aviation use?
MAPLAD18KP28A meets RTCA DO-160F Section 22 for lightning-induced transient susceptibility (multi-stroke), including Waveform 4 (Level 4) and Waveform 5A (Level 4). It also complies with IEC 61000-4-5 for secondary lightning protection at 42 Ω, 12 Ω, and 2 Ω source impedances (Classes 1–4). These certifications are documented in Microsemi's RF01215 Rev B specification report.
MAPLAD18KP28A 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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.5V
- Current - Peak Pulse (10/1000µs):
- 396A
- 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
MAPLAD18KP28A FAQ
1.How can I place an order for MAPLAD18KP28A through Aetrix?
Please submit a Request for Quotation (RFQ) for MAPLAD18KP28A 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 MAPLAD18KP28A reliable?
The price and inventory of MAPLAD18KP28A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAPLAD18KP28A is usually 5 days.
3.What payment methods are accepted for MAPLAD18KP28A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAPLAD18KP28A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAPLAD18KP28A?
MAPLAD18KP28A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAPLAD18KP28A 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 MAPLAD18KP28A?
For technical support, including MAPLAD18KP28A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAPLAD18KP28A requirements.
6.How does Aetrix verify that MAPLAD18KP28A is sourced from the original manufacturer or authorized distributors?
All MAPLAD18KP28A 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 MAPLAD18KP28A meets industry standards.
7.What is the process for return or replacement of MAPLAD18KP28A?
All MAPLAD18KP28A units undergo pre-shipment inspection (PSI). If there is an issue with MAPLAD18KP28A, 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 MAPLAD18KP28A part is unused and in its original packaging.
Return procedure for MAPLAD18KP28A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAPLAD18KP28A Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
