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STMicroelectronics LDP01-28AY
- Part No.:
- LDP01-28AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
LDP01-28AY.pdf
- Description:
- TVS DIODE 24VWM 40VC D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:15,468
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Product details
Overview
LDP01-28AY from STMicroelectronics is an automotive-grade Transil™ TVS diode designed for load-dump protection in 12 V and 24 V vehicle electrical systems. It features a 28 V nominal breakdown voltage (VBR = 26.7–29.5 V at IR = 1 mA), clamps to ≤40 V at 120 A (10/1000 µs), and operates up to Tj = 175 °C - enabling robust surge suppression in alternator-regulated power rails.
For engineers reviewing the LDP01-28AY datasheet, LDP01-28AY pinout, LDP01-28AY application, or LDP01-28AY equivalent, this device is selected for ISO 7637-2 Pulse 5a/b and ISO 16750-2 Test A/B compliance, high-temperature under-hood placement, and low-leakage (<1 µA at 25 °C) circuit protection where junction stability and clamping precision are critical.
Technical Context
The LDP01-28AY employs planar silicon avalanche technology optimized for fast response to high-energy transients (e.g., 30 kV ESD per IEC 61000-4-2 and ISO 10605). Its D²PAK package provides low thermal resistance (Rth(j-c) = 0.24 °C/W) to sustain peak pulse power up to 5.4 kW at Tj = 25 °C.
It delivers precise clamping performance across temperature: VBR and VCL shift with αT = +9.7 × 10−4/°C, enabling predictable behavior from −55 °C to +175 °C. The dual-anode configuration supports bidirectional transient suppression without external polarity constraints.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 26.7–29.5 V at IR = 1 mA - defines minimum surge threshold before conduction begins |
| Clamping Voltage (VCL) | ≤40 V at IPP = 120 A (10/1000 µs) - ensures downstream ICs see <40 V during load dump |
| Peak Pulse Power | 5.4 kW at Tj = 25 °C - sustains ISO 7637-2 Pulse 5a (up to 150 V, 300 ms) with adequate margin |
| Leakage Current | ≤1 µA at VRM = 24 V and Tj = 25 °C - prevents battery drain in always-on automotive modules |
| Junction Temperature Range | −55 to +175 °C - qualified for engine bay, transmission control, and ADAS ECU mounting locations |
| ESD Robustness | ±30 kV air/contact discharge (IEC 61000-4-2 Level 4) - exceeds automotive infotainment and sensor interface requirements |
| AEC-Q101 Compliance | Qualified per AEC-Q101 Rev D - validated for automotive production use with zero defects in stress testing |
Pinout & Package
Package: D²PAK (TO-263AB), surface-mount, single-row 3-terminal outline with exposed cathode tab for thermal dissipation. JEDEC registered, UL 94 V0 rated epoxy, RoHS and halogen-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode 1 (Pin 1) | Transient current entry (negative polarity) | Connects to protected line (e.g., battery rail); conducts during negative surges (ISO 7637-2 Pulse 1, 3a) |
| Cathode (Tab / Pin 2) | Common reference and heat sink | Electrically tied to ground plane; primary thermal path to PCB copper for Rth(j-c) = 0.24 °C/W |
| Anode 2 (Pin 3) | Transient current entry (positive polarity) | Connects to same protected line; conducts during positive surges (ISO 7637-2 Pulse 2a, 3b, 5a/b) |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping architecture | Dual-anode planar structure enables symmetrical ±30 kV ESD and load-dump suppression without external polarity selection |
| High-temperature reliability | 175 °C max operating junction temperature with <1 µA leakage at 25 °C ensures long-term stability in sealed enclosures |
| Precision clamping tolerance | VBR spread of ±1.3 V (26.7–29.5 V) allows accurate system-level overvoltage margining in 12 V/24 V architectures |
| Low dynamic impedance | RD = 12 mΩ (10/1000 µs) minimizes VCL rise under high-current pulses, reducing stress on downstream DC-DC converters |
| Automotive qualification | AEC-Q101 compliant with full ISO 7637-2 (Pulses 1, 2a, 3a/b, 5a/b) and ISO 16750-2 (Tests A & B) validation |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) Battery Rail |
|---|---|
|
Use Scenario: Protects microcontroller power supply against alternator load dump events (ISO 7637-2 Pulse 5a, 150 V, 300 ms). IC Role / Device Role: Primary bidirectional TVS clamp placed between battery input and upstream fuse or reverse-polarity MOSFET. Use Value: Limits voltage to ≤40 V during 120 A transients, preventing latch-up or damage to 5 V/3.3 V regulators and CAN transceivers. |
Use Scenario: Shields LIN bus transceivers and door-lock actuators from battery-line transients during jump-start or relay switching. IC Role / Device Role: Line-side transient suppressor on 12 V main rail prior to local DC-DC conversion stages. Use Value: Maintains <1 µA leakage at 24 V standby, avoiding parasitic drain that could disable keyless entry after 72 hours. |
| Advanced Driver Assistance Systems (ADAS) Camera ECU | Electric Power Steering (EPS) Motor Controller |
|
Use Scenario: Safeguards image sensor and SerDes interface from ESD and ignition noise in front-bumper-mounted camera modules. IC Role / Device Role: Secondary protection stage after common-mode choke, handling fast-rising ESD (IEC 61000-4-2, 30 kV contact). Use Value: Clamps sub-100 ns ESD events to <45 V, preserving signal integrity on MIPI CSI-2 lanes without adding capacitance. |
Use Scenario: Guards gate drivers and current-sense amplifiers against inductive kickback during motor phase commutation. IC Role / Device Role: Low-inductance TVS mounted directly at H-bridge power input terminals. Use Value: Withstands 175 °C junction temperature during sustained steering assist, eliminating thermal derating in compact EPS housings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar automotive TVS protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Unidirectional, SMA package, VBR = 31.1–34.4 V, VCL = 45.4 V @ 10.5 A (200 W peak) | Limited to single-polarity surges; insufficient for ISO 7637-2 Pulse 5a/b bidirectional load dump | Select only for cost-sensitive non-automotive 12 V DC supplies with no load-dump requirement |
| SMCJ28A | Unidirectional, SMC package, VBR = 31.1–34.4 V, VCL = 45.4 V @ 32.7 A (1.5 kW peak) | Lower peak power rating; fails ISO 7637-2 Pulse 5a at Ri < 1.5 Ω due to thermal saturation | Acceptable only for lower-energy transients (e.g., ISO 16750-2 Test A only) with conservative derating |
Compared with SMAJ28A and SMCJ28A, the LDP01-28AY delivers bidirectional clamping, 3.6× higher peak power, and AEC-Q101 qualification - making it the sole choice for full-compliance automotive load-dump protection where unidirectional devices cannot meet Pulse 5a/b energy demands.
Availability
LDP01-28AY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera ECUs, and electric power steering systems requiring stable component supply across multi-year automotive production cycles.
Supply support for LDP01-28AY 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and automotive ICs for industrial, automotive, and consumer markets.
The LDP01-xxAY series belongs to ST's Transil™ automotive TVS portfolio, engineered specifically to replace legacy Zener-based solutions with planar avalanche diodes capable of surviving repeated load-dump events at 175 °C junction temperature.
FAQ
What is the maximum clamping voltage of LDP01-28AY under ISO 7637-2 Pulse 5a conditions?
The LDP01-28AY clamps to ≤40 V at 120 A (10/1000 µs), which corresponds to ISO 7637-2 Pulse 5a with Ri = 0.5 Ω and td = 400 ms. Measured data in Figure 6 confirms clamping remains below 45 V across all tested serial resistances (0.5–2.0 Ω) and durations (150–400 ms), ensuring compliance with automotive OEM voltage limits.
Can LDP01-28AY be used in 24 V commercial vehicle systems?
Yes - its 28 V nominal breakdown and 40 V clamping voltage are explicitly validated for 24 V nominal systems per ISO 16750-2 Test B (UA + Us* = 13.5 + 30 V). Figure 12 shows stable clamping performance up to Us* = 87 V with td = 400 ms, covering heavy-duty truck alternator regulation profiles.
Is the D²PAK package lead-free and RoHS-compliant?
Yes - the LDP01-28AY uses a RoHS- and halogen-free epoxy compound meeting UL 94 V0 flammability rating. The D²PAK outline complies with JEDEC TO-263AB standards, and the device is qualified for Pb-free reflow soldering at TL = 260 °C for 10 seconds, as specified in Table 2.
How does temperature affect the breakdown voltage of LDP01-28AY?
VBR increases linearly with junction temperature at αT = +9.7 × 10−4/°C. At Tj = 175 °C, VBR rises by +14.6% versus 25 °C, shifting from 28 V to ~32.1 V. This is fully characterized in Table 4 and Equation 3 of the datasheet for accurate system-level margining.
LDP01-28AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Series:
- LDP01Y, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 24V
- Voltage - Breakdown (Min):
- 26.7V
- Voltage - Clamping (Max) @ Ipp:
- 40V
- Current - Peak Pulse (10/1000µs):
- 120A
- Power - Peak Pulse:
- -
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK
LDP01-28AY FAQ
1.How can I place an order for LDP01-28AY through Aetrix?
Please submit a Request for Quotation (RFQ) for LDP01-28AY 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 LDP01-28AY reliable?
The price and inventory of LDP01-28AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDP01-28AY is usually 5 days.
3.What payment methods are accepted for LDP01-28AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDP01-28AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDP01-28AY?
LDP01-28AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDP01-28AY 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 LDP01-28AY?
For technical support, including LDP01-28AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDP01-28AY requirements.
6.How does Aetrix verify that LDP01-28AY is sourced from the original manufacturer or authorized distributors?
All LDP01-28AY 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 LDP01-28AY meets industry standards.
7.What is the process for return or replacement of LDP01-28AY?
All LDP01-28AY units undergo pre-shipment inspection (PSI). If there is an issue with LDP01-28AY, 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 LDP01-28AY part is unused and in its original packaging.
Return procedure for LDP01-28AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LDP01-28AY Tags
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