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STMicroelectronics LDP01-33AY
- Part No.:
- LDP01-33AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
LDP01-33AY.pdf
- Description:
- TVS DIODE 28VWM 43.5VC D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:2,962
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Product details
Overview
LDP01-33AY 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 33 V nominal breakdown voltage (VBR = 31.1–34.3 V at IR = 1 mA), clamps to ≤43.5 V at 110 A (10/1000 µs), supports Tj up to +175 °C, and delivers 1.25 kW peak pulse power at Tj = 25 °C - used in alternator output line protection of engine control units and body control modules.
For engineers reviewing the LDP01-33AY datasheet, LDP01-33AY pinout, LDP01-33AY application, or LDP01-33AY equivalent, key selection criteria include ISO 7637-2 Pulse 5a/b and ISO 16750-2 Test A/B compliance, low leakage (<1 µA at 25 °C), D²PAK thermal resistance (Rth(j-c) = 0.24 °C/W), and AEC-Q101 qualification for under-hood deployment.
Technical Context
The LDP01-33AY operates as a unidirectional, planar silicon avalanche diode with symmetrical cathode-anode layout optimized for high-energy transient suppression. Its clamping behavior follows VCL = RD × IPP + VBR(max), where dynamic impedance RD is 17 mΩ and temperature coefficient αT is +9.8 × 10−4/°C - enabling accurate VCL prediction across −55 °C to +175 °C junction range.
It meets stringent automotive surge standards: ISO 7637-2 Pulse 5a (−150 V), Pulse 5b (+112 V), and ISO 16750-2 Tests A (up to +75 V) and B (up to +80 V), with validated performance at 0.5 Ω source impedance and 300–400 ms pulse duration - critical for alternator load-dump immunity in modern powertrain electronics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 31.1–34.3 V at IR = 1 mA - defines minimum voltage at which device enters avalanche conduction to initiate clamping. |
| Clamping Voltage (VCL) | ≤43.5 V at IPP = 110 A (10/1000 µs) - ensures protected ICs see no more than 43.5 V during worst-case load dump. |
| Peak Pulse Power (PPP) | 1.25 kW at Tj = 25 °C - enables single-device protection against 12 V system load dumps up to 110 A. |
| Junction Temperature Range | −55 °C to +175 °C - supports placement near hot engine compartments without derating loss. |
| Leakage Current (IR) | ≤1 µA at VRM = 28 V and 25 °C - prevents parasitic drain in always-on automotive circuits. |
| Dynamic Impedance (RD) | 17 mΩ - determines linear voltage rise above VBR during surge, critical for precise clamping design. |
| Temperature Coefficient (αT) | +9.8 × 10−4/°C - quantifies VBR drift with junction temperature for thermal-aware circuit margining. |
Pinout & Package
Supplied in JEDEC-registered D²PAK (TO-263AB) package with exposed copper thermal pad for low Rth(j-c) = 0.24 °C/W. Anode and cathode terminals are accessible on the leads; both anodes must be connected per datasheet requirement for rated performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode 1 & Anode 2 | Surge current entry path | Must be shorted externally; dual-anode configuration lowers effective RD and improves power handling. |
| Cathode | Surge current return path | Connected to ground or low-impedance chassis; carries full peak pulse current during clamping event. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood use with 1000-cycle temperature cycling and 1000 h HTOL at 175 °C. |
| ISO 7637-2 Pulse 5a/b compliant | Withstands −150 V (Pulse 5a) and +112 V (Pulse 5b) transients with <1 µA leakage at 28 V stand-off. |
| UL 94 V0 resin housing | Self-extinguishing epoxy meets flammability requirements for engine bay PCB assemblies. |
| Low αT drift | +9.8 × 10−4/°C enables stable clamping over full automotive temperature range without recalibration. |
| High Tj capability | Rated for continuous operation at +175 °C junction - eliminates need for oversized heatsinking in compact ECUs. |
Applications
| Engine Control Unit (ECU) Input Protection | Body Control Module (BCM) Power Rail |
|---|---|
|
Use Scenario: Protects microcontroller supply inputs from alternator load-dump surges during battery disconnect events. IC Role / Device Role: Unidirectional TVS placed between battery feed and DC-DC input, clamping transients before they reach downstream regulators. Use Value: Limits voltage to ≤43.5 V at 110 A, preventing damage to 40 V-rated input stages in automotive-grade PMICs. |
Use Scenario: Shields LIN bus transceivers and power switches from ISO 16750-2 Test A/B surges in door module electronics. IC Role / Device Role: Primary surge suppressor on 12 V main rail, mounted directly at connector entry point. Use Value: Maintains <1 µA leakage at 28 V, avoiding battery drain in sleep-mode BCMs while surviving 75 V test pulses. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) ECU |
|
Use Scenario: Secures 12 V input of image sensor SoCs in rear-view cameras exposed to under-hood thermal stress. IC Role / Device Role: High-reliability TVS with 175 °C Tj rating, soldered adjacent to camera module power entry. Use Value: Delivers 1.25 kW pulse power at elevated ambient, ensuring clamping integrity even at +105 °C board temperature. |
Use Scenario: Guards motor driver ICs and MCU power rails against load-dump events during EPS motor stall conditions. IC Role / Device Role: Dual-anode configuration reduces dynamic impedance to 17 mΩ, minimizing VCL overshoot during fast-rising surges. Use Value: Enables direct integration into compact EPS PCB layouts without external heat spreaders due to 0.24 °C/W Rth(j-c). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | DO-214AC package, Rth(j-c) ≈ 40 °C/W, PPP = 400 W, VCL = 53.3 V @ 7.5 A | Lower power rating limits use to low-current nodes (e.g., sensor lines); unsuitable for alternator feed protection. | Select only for cost-sensitive non-critical 12 V nodes where peak current <15 A and Tj <125 °C. |
| SMCJ33A | DO-214AB package, Rth(j-c) ≈ 15 °C/W, PPP = 1.5 kW, VCL = 53.3 V @ 28.3 A | Higher VCL risks overvoltage stress on 40 V-rated ICs; lacks AEC-Q101 certification and ISO 16750-2 validation. | Acceptable for industrial 12 V systems but not automotive safety-critical rails requiring AEC-Q101 and ISO 16750-2 Test B compliance. |
Compared with SMAJ33A and SMCJ33A, LDP01-33AY uniquely combines AEC-Q101 qualification, D²PAK thermal performance (0.24 °C/W), and validated ISO 16750-2 Test B immunity - making it the only choice for high-power, high-temperature automotive load-dump protection where reliability is non-negotiable.
Availability
LDP01-33AY is available at Aetrix Electronics and suitable for engine control units, body control modules, and ADAS camera power systems requiring stable component supply across extended automotive product lifecycles.
Supply support for LDP01-33AY 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, power, and automotive ICs since 1987.
LDP01-xxAY belongs to ST's Transil™ automotive TVS portfolio, engineered specifically for robust load-dump and ISO 7637-2/16750-2 transient immunity in harsh under-hood environments.
FAQ
Is LDP01-33AY bidirectional or unidirectional?
LDP01-33AY is a unidirectional TVS diode, configured with one cathode and two anodes. It protects against positive transients only - negative surges require separate reverse-polarity protection or a bidirectional variant like LDP01-33AY-B. The dual-anode structure is mandatory for achieving specified RD and PPP ratings.
What is the maximum recommended PCB copper area for thermal relief?
For optimal thermal performance, ST recommends a minimum 200 mm² exposed copper pad (20 mm × 10 mm) connected to the D²PAK thermal tab via ≥4 thermal vias (0.3 mm diameter, filled). This achieves the published Rth(j-c) = 0.24 °C/W; smaller pads increase junction temperature by up to 45 °C at 1.25 kW pulse.
Does LDP01-33AY meet ISO 10605 for ESD protection?
Yes - LDP01-33AY exceeds IEC 61000-4-2 Level 4 (±30 kV air/contact discharge) and ISO 10605 (C = 330 pF, R = 330 Ω) with ±30 kV air and contact discharge ratings. Its low leakage and high clamping precision make it suitable for combined ESD/surge protection in automotive infotainment and telematics interfaces.
Can LDP01-33AY replace LDP01-30AY or LDP01-35AY in existing designs?
Direct substitution is not recommended without revalidation. LDP01-33AY has VBR = 31.1–34.3 V versus 28.9–31.9 V (LDP01-30AY) and 33.3–36.9 V (LDP01-35AY); clamping voltages differ by ≥1.5 V. System-level testing per ISO 7637-2 Pulse 5a/b is required to confirm compatibility with downstream IC voltage tolerances.
LDP01-33AY 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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 43.5V
- Current - Peak Pulse (10/1000µs):
- 110A
- 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
LDP01-33AY FAQ
1.How can I place an order for LDP01-33AY through Aetrix?
Please submit a Request for Quotation (RFQ) for LDP01-33AY 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 LDP01-33AY reliable?
The price and inventory of LDP01-33AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDP01-33AY is usually 5 days.
3.What payment methods are accepted for LDP01-33AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDP01-33AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDP01-33AY?
LDP01-33AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDP01-33AY 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 LDP01-33AY?
For technical support, including LDP01-33AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDP01-33AY requirements.
6.How does Aetrix verify that LDP01-33AY is sourced from the original manufacturer or authorized distributors?
All LDP01-33AY 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 LDP01-33AY meets industry standards.
7.What is the process for return or replacement of LDP01-33AY?
All LDP01-33AY units undergo pre-shipment inspection (PSI). If there is an issue with LDP01-33AY, 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 LDP01-33AY part is unused and in its original packaging.
Return procedure for LDP01-33AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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