My Inquiry
My Account
Alpha & Omega Semiconductor Inc. SMDJ33A
- Part No.:
- SMDJ33A
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ33A.pdf
- Description:
- 1CH 33V UNIDIRECTIONAL 3000W SMD
- Quantity:
- Payment:
- Shipping:
Inventory:9,857
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMDJ33A from Alpha & Omega Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power lines and signal interfaces. It features a 33 V reverse standoff voltage (VRWM), 36.7–40.6 V breakdown voltage (VBR) at 1 mA, 53.3 V maximum clamping voltage at 56.3 A peak pulse current, and 3000 W peak pulse power dissipation on a 10/1000 µs waveform - deployed in industrial motor drives to protect IGBT gate drivers from inductive switching transients.
For engineers reviewing the SMDJ33A datasheet, pinout, applications, or equivalent options, key selection criteria include unidirectional polarity, DO-214AB package compatibility with high-current PCB layouts, clamping performance under repetitive 0.01% duty cycle surges, and thermal resistance (RθJL = 15 °C/W) for lead-mounted thermal management.
Technical Context
The SMDJ33A operates as a silicon avalanche diode, triggered by reverse-biased overvoltage events exceeding its specified VBR range. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (≤2 µA @ VRWM), while the low-profile DO-214AB (SMC J-Bend) package supports automated placement and high thermal conduction via copper pad mounting.
It delivers sub-1.0 ps response time from 0 V to VBR and meets J-STD-020 MSL Level 1 (260 °C reflow peak), enabling robust integration into automotive body control modules and telecom power supplies where fast clamping and assembly reliability are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 33.0 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC bias margin in 24 V/32 V systems. |
| VBR @ IT=1 mA | 36.7–40.6 V - Measured breakdown range confirming tight tolerance for predictable trigger threshold in precision protection circuits. |
| Vc @ IPPM | 53.3 V - Clamping voltage at 56.3 A peak pulse; limits downstream IC stress during 3000 W transient events. |
| PPPM (10/1000 µs) | 3000 W - Peak pulse power rating indicating capability to absorb high-energy lightning-induced surges without failure. |
| TJ max | +150 °C - Maximum junction temperature enabling operation in under-hood automotive environments or enclosed industrial enclosures. |
| RθJL | 15 °C/W - Thermal resistance from junction to lead; enables direct heat sinking through PCB copper pads for sustained surge handling. |
| IR @ VRWM | ≤2.0 µA - Low reverse leakage ensuring minimal standby power loss and signal integrity in always-on monitoring circuits. |
Pinout & Package
DO-214AB (SMC J-Bend) package: molded plastic case with matte tin lead-free plating, JEDEC-compliant outline, cathode indicated by color band; mounted on 8.0 mm × 8.0 mm copper pads per terminal for optimal thermal and current handling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current path / surge return path | Connected to system ground or low-impedance return plane; carries full IPPM during clamping. |
| Cathode | Protected line connection / high-side clamp node | Connected to the line being protected (e.g., 24 V rail); voltage referenced to anode during avalanche conduction. |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | <1.0 ps - Enables clamping before sensitive downstream logic or analog circuitry sustains damage from ESD or EFT events. |
| Glass passivated junction | Stable VBR drift <0.1% × VBR/°C - Ensures consistent clamping threshold across industrial temperature ranges (−55 to +150 °C). |
| Built-in strain relief | Mechanical reinforcement at lead-to-body interface - Prevents solder joint fracture under thermal cycling or board flex in harsh environments. |
| MSL Level 1 rating | Compatible with standard 260 °C Pb-free reflow profiles - Eliminates pre-bake requirements and supports high-yield SMT assembly. |
| UL 94V-0 flammability | Self-extinguishing plastic housing - Meets safety standards for enclosed power supply and industrial control applications. |
Applications
| Industrial Motor Drives | Automotive Body Control Modules |
|---|---|
Use Scenario: Protection of IGBT gate driver inputs against inductive kickback during PWM switching in 24 V DC bus inverters. IC Role / Device Role: Unidirectional TVS clamp placed between gate and source to limit voltage excursion to ≤53.3 V during turn-off transients. Use Value: Prevents gate oxide rupture in SiC/IGBT drivers by clamping within 1 ps and dissipating up to 3000 W without degradation over 10⁵ cycles. | Use Scenario: Surge suppression on LIN bus lines exposed to load dump and battery reversal in door module ECUs. IC Role / Device Role: Primary overvoltage protector on 12 V supply rail feeding LIN transceivers and microcontrollers. Use Value: Maintains ≤2 µA leakage at 12 V standby, ensuring low quiescent current compliance while surviving ISO 7637-2 Pulse 5a (120 V/500 ms) events. |
| Telecom Power Supplies | Renewable Energy Inverters |
Use Scenario: Input-stage protection on 48 V DC-DC converters subjected to lightning-induced surges on outdoor telecom cabinets. IC Role / Device Role: First-line TVS on primary input rail upstream of bulk capacitors and controllers. Use Value: Withstands 3000 W pulses at 10/1000 µs and derates predictably to 75% power at +75 °C ambient - validated per IEC 61000-4-5. | Use Scenario: DC link surge protection in solar string inverters where PV array transients couple into MPPT controller rails. IC Role / Device Role: Bidirectional-capable variant not used; SMDJ33A serves unidirectional clamp on grounded negative rail. Use Value: RθJL = 15 °C/W allows direct thermal coupling to heatsinked copper pour, sustaining repeated 56.3 A pulses without thermal runaway. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC33 | Same DO-214AB package, 33 V VRWM, but lower PPPM (1500 W) and higher Vc (60 V @ 25 A); ±5% VBR tolerance vs. SMDJ33A's ±5.5%. | Lower energy handling limits use to sub-1500 W surge environments; unsuitable for IEC 61000-4-5 Level 4 compliance. | Select SAC33 only when cost sensitivity outweighs surge margin requirements and peak currents remain below 25 A. |
| 1.5KE33A | Through-hole DO-15 package (not SMD), same 33 V VRWM and 3000 W rating, but slower response (>1 ns) and higher RθJA (60 °C/W). | Requires PCB real estate for axial leads and lacks MSL1 reflow compatibility; incompatible with high-density automated assembly. | Choose 1.5KE33A only for legacy through-hole designs or prototyping where thermal constraints allow larger heatsinking. |
Compared with SAC33 and 1.5KE33A, the SMDJ33A uniquely combines surface-mount scalability, sub-1 ps response, and 3000 W capability in a thermally optimized DO-214AB package - making it the preferred choice for space-constrained, high-reliability industrial and automotive surge protection.
Availability
SMDJ33A is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, and telecom power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.
Supply support for SMDJ33A 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
Alpha & Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in high-efficiency MOSFETs, TVS diodes, and power ICs for industrial, computing, and automotive markets.
The SMDJ series is engineered for high-power transient suppression in demanding DC applications, emphasizing low clamping voltage, fast response, and robust thermal performance in surface-mount form factors.
FAQ
What is the maximum clamping voltage of the SMDJ33A under rated surge conditions?
The SMDJ33A exhibits a maximum clamping voltage (VC) of 53.3 V when subjected to its rated peak pulse current of 56.3 A on a 10/1000 µs waveform. This value is measured per JEDEC standards and ensures downstream components see no more than 53.3 V during worst-case transient events, directly supporting design margining for 3.3 V, 5 V, and 24 V logic and power stages in the SMDJ33A application space.
Is the SMDJ33A suitable for bidirectional surge protection?
No, the SMDJ33A is a unidirectional TVS diode intended for DC line protection with defined polarity. For bidirectional applications, the SMDJ33CA variant must be used - it shares the same VRWM and clamping specs but conducts symmetrically in both directions. The SMDJ33A datasheet explicitly specifies unidirectional polarity, and using it in AC or floating configurations risks incomplete protection or device failure.
What is the thermal resistance from junction to lead (RθJL) for the SMDJ33A, and why does it matter?
The SMDJ33A has a typical junction-to-lead thermal resistance (RθJL) of 15 °C/W when mounted on 8.0 mm × 8.0 mm copper pads. This low value enables efficient heat transfer from the silicon junction to the PCB, allowing the SMDJ33A to sustain repetitive 3000 W surges without exceeding its 150 °C maximum junction temperature - a critical parameter for reliability in motor drive and renewable energy inverters where surge frequency exceeds 1 Hz.
Does the SMDJ33A meet lead-free assembly requirements?
Yes, the SMDJ33A features matte tin lead-free plating and is rated MSL Level 1 per J-STD-020, with a maximum peak reflow temperature of 260 °C. It is fully compatible with standard Pb-free SMT processes and requires no pre-baking, supporting high-yield manufacturing for automotive and industrial customers requiring RoHS and AOS Green compliance (halogen-free, Pb-free).
How does the SMDJ33A's response time compare to standard Zener diodes?
The SMDJ33A achieves a typical response time of less than 1.0 ps from 0 V to VBR, significantly faster than conventional Zener diodes (typically >1 ns). This ultrafast avalanche behavior ensures clamping initiates before voltage overshoot damages sensitive gate drivers or communication ICs - a key differentiator confirmed in the SMDJ33A datasheet and essential for protecting modern SiC and GaN power stages where dV/dt exceeds 100 V/ns.
SMDJ33A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 56.3A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB
SMDJ33A FAQ
1.How can I place an order for SMDJ33A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ33A 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 SMDJ33A reliable?
The price and inventory of SMDJ33A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ33A is usually 5 days.
3.What payment methods are accepted for SMDJ33A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ33A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ33A?
SMDJ33A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ33A 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 SMDJ33A?
For technical support, including SMDJ33A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ33A requirements.
6.How does Aetrix verify that SMDJ33A is sourced from the original manufacturer or authorized distributors?
All SMDJ33A 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 SMDJ33A meets industry standards.
7.What is the process for return or replacement of SMDJ33A?
All SMDJ33A units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ33A, 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 SMDJ33A part is unused and in its original packaging.
Return procedure for SMDJ33A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMDJ33A 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
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
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…
