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Taiwan Semiconductor Corporation SMAJ33A
- Part No.:
- SMAJ33A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ33A.pdf
- Description:
- TVS DIODE 33VWM 53.3VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,190
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Product details
Overview
SMAJ33A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for primary-side overvoltage protection in DC power rails. It features a 33 V working stand-off voltage (VWM), 36.7–40.6 V breakdown voltage (VBR) at 1 mA test current, and clamps to ≤53.3 V at 7.5 A peak impulse current under 10/1000 µs waveform - enabling robust surge immunity in 24 V industrial power supplies.
For engineers reviewing the SMAJ33A datasheet, SMAJ33A pinout, SMAJ33A application, or SMAJ33A equivalent, key selection criteria include its DO-214AC (SMA) package compatibility with automated placement, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, ≤1.0 ps response time, and 400 W peak pulse power rating at 25 °C.
Technical Context
The SMAJ33A operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its specified breakdown range. Its glass-passivated junction ensures stable VBR tolerance and low leakage (<1 µA at 33 V), while the 10/1000 µs waveform-rated clamping performance targets automotive and industrial load-dump transients.
Thermal derating begins above 25 °C ambient per Fig.2, with maximum junction temperature limited to 150 °C and storage range spanning −55 °C to +150 °C. The device is rated for 40 A non-repetitive forward surge (8.3 ms half-sine) and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous reverse operating voltage before conduction begins; sets system rail margin for 24 V nominal DC inputs. |
| VBR min/max | 36.7 V / 40.6 V at IT = 1 mA - Tight breakdown window ensures predictable turn-on during transients without premature leakage. |
| VC @ IPPM | ≤53.3 V at 7.5 A - Clamping voltage defines worst-case downstream voltage stress during 10/1000 µs surge events. |
| PPPM | 400 W (10/1000 µs) - Peak pulse power handling capacity validated per REA-defined waveform for automotive load dump immunity. |
| IR @ VWM | ≤1 µA - Ultra-low reverse leakage preserves efficiency in always-on power monitoring circuits and battery-backed systems. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with cathode band marking; compatible with IPC-7351B footprint and reflow profiles. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band on one end. Weight ≈ 0.060 g. Complies with J-STD-002 solderability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to system ground or low-side return path; carries surge current during clamping. |
| Cathode | Reverse-biased input terminal | Connected to protected line (e.g., 24 V rail); initiates avalanche conduction when VREV > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR over temperature and lifetime; eliminates parameter drift due to moisture or oxidation. |
| ≤1.0 ps response time | Enables suppression of fast-rising ESD and lightning-induced transients before sensitive downstream ICs are damaged. |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load disconnect), Pulse 2a/2b (battery interruption), and Pulse 3a/3b (switching noise) in automotive ECUs. |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU; supports lead-free assembly and environmental compliance programs. |
Applications
| Switching Mode Power Supply (SMPS) | On-board DC/DC Converter |
|---|---|
Use Scenario: Input stage protection against line surges and back-EMF from upstream AC/DC converters. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between input rail and ground to shunt transient energy before it reaches PWM controller or MOSFET gate drivers. Use Value: Limits peak voltage to ≤53.3 V during 400 W transients, preserving reliability of 65 V-rated input capacitors and 100 V FETs. | Use Scenario: Protection of point-of-load (POL) converters in programmable logic controllers and motor drives. IC Role / Device Role / Timing Role: Standoff-rated transient suppressor on 24 V intermediate bus feeding isolated buck regulators. Use Value: Maintains <1 µA leakage at 33 V, minimizing standby power loss while delivering sub-50 ns clamping response to switching noise. |
| Lighting Application | Adapters |
Use Scenario: Surge protection in LED driver modules subjected to mains-coupled transients and hot-plug events. IC Role / Device Role / Timing Role: Primary-side TVS on constant-current output rail to prevent overvoltage damage to LED strings and current-sense amplifiers. Use Value: Withstands 40 A single-half-sine surge (8.3 ms), supporting EN 61000-4-5 Level 3 immunity in commercial lighting fixtures. | Use Scenario: Input-stage protection in wall-mounted AC/DC adapters for consumer electronics. IC Role / Device Role / Timing Role: Unidirectional suppressor across secondary-side DC output to absorb coupling noise from transformer leakage inductance. Use Value: 33 V VWM aligns with 24 V adapter outputs; DO-214AC package enables high-density layout without thermal vias. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33 | Higher clamping voltage (59.0 V vs. 53.3 V at same IPPM); wider VBR range (36.7–44.9 V). | Less effective voltage limiting in systems with tight downstream IC tolerances (e.g., 60 V max-rated MOSFETs). | Select SMAJ33A when clamping headroom below 55 V is required; SMAJ33 suits less constrained 24 V systems. |
| SMBJ33A | Same electrical specs but in DO-214AA (SMB) package - 2.5 mm wider body, higher thermal mass, 600 W PPPM rating. | Preferred where board space allows larger footprint and higher surge margin is needed (e.g., industrial motor control). | Choose SMBJ33A for enhanced thermal endurance; SMAJ33A remains optimal for space-constrained 24 V adapter designs. |
Compared with SMAJ33 and SMBJ33A, the SMAJ33A delivers the tightest clamping (53.3 V), smallest footprint (DO-214AC), and lowest leakage - making it ideal for compact, high-reliability 24 V power interfaces where voltage headroom and PCB area are critical constraints.
Availability
SMAJ33A is available at Aetrix Electronics and suitable for switching mode power supplies, on-board DC/DC converters, and industrial lighting applications requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMAJ33A 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMAJ series was developed specifically for surface-mount transient suppression in automotive, industrial, and consumer power systems - emphasizing ISO 7637-2 compliance, automated assembly readiness, and high-reliability junction passivation.
FAQ
What is the maximum clamping voltage of the SMAJ33A under standard test conditions?
The SMAJ33A has a maximum clamping voltage (VC) of 53.3 V when subjected to a 7.5 A peak impulse current with a 10/1000 µs waveform at 25 °C ambient. This value is measured per REA-defined pulse shape and reflects worst-case voltage seen by downstream components during surge events. The SMAJ33A maintains this clamping performance across its qualified operating temperature range.
Does the SMAJ33A meet automotive transient immunity standards?
Yes, the SMAJ33A meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a/2b (battery interruption), and Pulse 3a/3b (switching noise). Its 400 W peak pulse power rating, fast ≤1.0 ps response time, and controlled VBR tolerance make it suitable for protecting ECUs, body control modules, and infotainment power supplies in 12 V and 24 V vehicle architectures.
How does the SMAJ33A differ from the SMAJ33 in terms of electrical performance?
The SMAJ33A offers tighter breakdown voltage (36.7–40.6 V) and lower clamping voltage (53.3 V vs. 59.0 V at 7.5 A) than the SMAJ33 (36.7–44.9 V, 59.0 V VC). Both share identical VWM (33 V) and package (DO-214AC), but the SMAJ33A's narrower VBR distribution improves consistency in surge turn-on threshold, making SMAJ33A preferable for designs requiring precise voltage limiting.
Is the SMAJ33A RoHS and halogen-free compliant?
Yes, the SMAJ33A is fully RoHS compliant per EU Directive 2011/65/EU and halogen-free per IEC 61249-2-21. Its molding compound meets UL 94V-0 flammability rating, and matte tin-plated leads satisfy J-STD-002 solderability requirements - ensuring compatibility with lead-free reflow processes and environmental compliance programs.
What is the polarity configuration and marking convention for the SMAJ33A?
The SMAJ33A is a unidirectional TVS diode with cathode indicated by a band on the DO-214AC (SMA) package body. Its marking code is "CM", printed adjacent to the cathode band. During PCB layout, the banded end must connect to the protected line (e.g., 24 V rail), while the anode connects to ground - reversing polarity would disable transient suppression capability.
SMAJ33A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- 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):
- 7.5A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ33A FAQ
1.How can I place an order for SMAJ33A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ33A 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 SMAJ33A reliable?
The price and inventory of SMAJ33A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ33A is usually 5 days.
3.What payment methods are accepted for SMAJ33A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ33A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ33A?
SMAJ33A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ33A 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 SMAJ33A?
For technical support, including SMAJ33A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ33A requirements.
6.How does Aetrix verify that SMAJ33A is sourced from the original manufacturer or authorized distributors?
All SMAJ33A 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 SMAJ33A meets industry standards.
7.What is the process for return or replacement of SMAJ33A?
All SMAJ33A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ33A, 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 SMAJ33A part is unused and in its original packaging.
Return procedure for SMAJ33A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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