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Diodes Incorporated SMF4L33A-7
- Part No.:
- SMF4L33A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L33A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:7,709
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Product details
Overview
SMF4L33A-7 from Diodes Incorporated is a unidirectional 33V transient voltage suppressor (TVS) diode in DO-219AA package, rated for 400W peak pulse power (10/1000µs), 53.3V clamping voltage at 7.5A surge current, and <0.5µA reverse leakage at 33V working voltage. It delivers ESD protection per IEC61000-4-2 (±30kV air/contact) and is used for battery contact and automotive power rail surge suppression.
For engineers reviewing the SMF4L33A-7 datasheet, SMF4L33A-7 pinout, SMF4L33A-7 application, or SMF4L33A-7 equivalent, key selection criteria include clamping voltage margin vs. protected IC VMAX, standoff voltage alignment with system operating voltage, thermal resistance (RθJA = 96°C/W), and DO-219AA footprint compatibility with high-density PCB layouts.
Technical Context
This TVS operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its 36.7V minimum breakdown (VBR) at 1mA test current. Its fast response (<1.0ns from 0V to VBR) ensures protection of downstream components before transient energy propagates.
The device features a low 53.3V maximum clamping voltage (VC) at 7.5A peak surge current (IRSM), enabling robust overvoltage suppression on 24–36V automotive and industrial power rails while maintaining safe margin below typical 60V-rated load switches and controllers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform): sustains single high-energy transients without failure |
| Working Peak Reverse Voltage | 33V: matches nominal 24V/36V systems with 20% margin above max operating voltage |
| Breakdown Voltage (Min) | 36.7V @ 1mA: ensures reliable triggering above normal operating conditions |
| Clamping Voltage (Max) | 53.3V @ 7.5A: limits voltage seen by protected circuit during worst-case surge |
| Reverse Leakage Current | <0.5µA @ 33V: negligible standby power loss in always-on battery circuits |
| ESD Rating | ±30kV (air/contact per IEC61000-4-2): protects against human-body-model and contact discharge events |
| Thermal Resistance (Junction-to-Ambient) | 96°C/W: requires minimal copper area (1"×1", 2 oz Cu) for safe steady-state operation |
Pinout & Package
Package: DO-219AA - surface-mount, ultra-low-profile (max height 0.75mm), molded green plastic (UL 94V-0), cathode band marked on top for polarity identification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to ground or low-side return path in unidirectional clamp configuration |
| Cathode | Protected line connection point | Connected to the rail requiring surge protection (e.g., battery input, CAN bus VCC) |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse rating | Enables single-device protection against ISO 7637-2 Pulse 1/2a/3a surges in automotive 12V/24V systems |
| DO-219AA footprint | Reduces board space by 40% vs. SMA/SMB packages while maintaining thermal performance |
| Fast response time | <1.0ns turn-on ensures clamping activation before most microcontroller I/O pins experience overstress |
| Halogen- and antimony-free "Green" construction | Meets JEDEC J-STD-020 moisture sensitivity Level 1 and RoHS 3 compliance without derating |
| Low clamping ratio (VC/VWM) | 1.61 ratio (53.3V/33V) provides tight voltage control critical for protecting 36V-tolerant analog front-ends |
Applications
| Automotive Body Control Module (BCM) | Industrial 24V PLC Input Protection |
|---|---|
|
Use Scenario: Protects 24V supply rail of BCM microcontrollers and CAN transceivers against load dump and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery feed and local LDO input, clamping transients before they reach sensitive logic. Use Value: 53.3V clamping ensures voltage stays below 60V absolute maximum rating of common 24V-input PMICs and CAN PHYs. |
Use Scenario: Shields digital input channels of programmable logic controllers from field-wiring induced surges and ESD. IC Role / Device Role / Timing Role: Mounted directly at terminal block entry point, acting as first-line defense before optocoupler or Schmitt-trigger input stage. Use Value: Sub-1ns response prevents latch-up in 3.3V/5V logic interfaces connected via long cables exposed to industrial noise. |
| Smart Battery Pack Management | Telematics Unit Power Input |
|
Use Scenario: Guards BMS MCU and cell monitor ICs against ESD events during hot-plug battery connection and charge/discharge switching. IC Role / Device Role / Timing Role: Placed across battery terminals (cathode to pack+, anode to pack−), suppressing ±30kV contact discharges per IEC61000-4-2. Use Value: <0.5µA leakage preserves battery shelf life over multi-year deployments in remote sensor nodes. |
Use Scenario: Secures LTE/GNSS module power input against ignition transients and antenna-coupled RF energy in vehicle-mounted telematics. IC Role / Device Role / Timing Role: Integrated into DC-DC converter input filter stage, limiting voltage overshoot during ISO 7637-2 Pulse 5a (load dump). Use Value: 400W rating handles 120V/10ms load dump pulses without degradation, eliminating need for parallel TVS devices. |
Availability
SMF4L33A-7 is available at Aetrix Electronics and suitable for automotive body electronics, industrial 24V PLCs, smart battery management systems, and telematics power input protection requiring stable component supply and AEC-Q qualified alternatives.
Supply support for SMF4L33A-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and distribution operations across Asia, Europe, and North America.
The SMF4L series belongs to Diodes' high-reliability transient suppression portfolio, engineered specifically for automotive and industrial applications demanding AEC-Q200-compliant surge immunity, low-profile packaging, and guaranteed clamping performance under temperature extremes.
FAQ
What is the polarity configuration of SMF4L33A-7?
SMF4L33A-7 is a unidirectional TVS diode, indicated by the cathode band marking on the DO-219AA package top surface. It conducts only in reverse bias during overvoltage events and blocks voltage in forward direction up to 3V at 16A, making it suitable for DC power rail protection where polarity is fixed.
How does SMF4L33A-7 compare to SMAJ33A in terms of board space and thermal performance?
SMF4L33A-7 uses DO-219AA (1.90 × 2.80 mm) versus SMAJ33A's DO-214AC (4.3 × 2.6 mm), reducing footprint area by ~55%. Its RθJA of 96°C/W is measured on a 1"×1" 2 oz Cu pad-comparable to SMAJ33A's 90°C/W-enabling equivalent thermal handling in space-constrained designs without thermal derating penalties.
Is SMF4L33A-7 qualified for automotive use per AEC-Q200?
No-SMF4L33A-7 is the commercial-grade variant. For automotive qualification, Diodes offers the Q-suffix version SMF4L33AQ-7, which is AEC-Q200 Grade 1 (−40°C to +125°C), manufactured in IATF 16949-certified facilities, and supported with PPAP documentation. The base part lacks change control and automotive-specific reliability testing.
What is the recommended PCB pad layout for optimal thermal and electrical performance?
Diodes specifies a pad layout with 1.34 mm pad width (X), 4.20 mm pad length (X1), and 1.80 mm spacing (Y) for DO-219AA. Use 2 oz copper on FR-4 with thermal vias under the cathode pad to achieve the rated RθJA of 96°C/W; insufficient copper area increases junction temperature and reduces surge endurance.
SMF4L33A-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-219AA
- Series:
- SMF4L
- 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AA
SMF4L33A-7 FAQ
1.How can I place an order for SMF4L33A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L33A-7 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 SMF4L33A-7 reliable?
The price and inventory of SMF4L33A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L33A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L33A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L33A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L33A-7?
SMF4L33A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L33A-7 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 SMF4L33A-7?
For technical support, including SMF4L33A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L33A-7 requirements.
6.How does Aetrix verify that SMF4L33A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L33A-7 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 SMF4L33A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L33A-7?
All SMF4L33A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L33A-7, 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 SMF4L33A-7 part is unused and in its original packaging.
Return procedure for SMF4L33A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L33A-7 Tags
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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