My Inquiry
My Account
Diodes Incorporated SMF4L12A-7
- Part No.:
- SMF4L12A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L12A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:9,372
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF4L12A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in DC power rails and signal lines. It features a 12V working peak reverse voltage (VRWM), 13.3V minimum breakdown voltage (VBR), clamping voltage of 19.9V at 20.1A peak pulse current, and IEC61000-4-2 ±30kV ESD immunity. It is used in automotive body control modules to protect LIN bus transceivers from load dump and ESD events.
For engineers reviewing the SMF4L12A-7 datasheet, SMF4L12A-7 pinout, SMF4L12A-7 application, or SMF4L12A-7 equivalent, key selection criteria include clamping voltage margin relative to protected IC VCC, unidirectional polarity alignment with DC rail topology, DO-219AA footprint compatibility, and AEC-Q200 readiness for automotive deployment.
Technical Context
This TVS operates as a voltage-clamped shunt device triggered above its breakdown threshold, diverting surge energy to ground while limiting downstream voltage excursion. Its sub-1ns response time ensures protection against fast transients such as ESD and inductive switching spikes.
The device uses planar junction technology in a low-inductance DO-219AA package, enabling stable clamping performance under 10/1000µs waveform stress. Thermal resistance (RθJA = 96°C/W) and 1.0W steady-state dissipation support continuous operation in ambient temperatures up to +125°C when mounted on standard FR-4 PCBs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform): sustains single high-energy surges without failure |
| Working Peak Reverse Voltage | 12V: maximum continuous DC voltage applied without leakage exceeding 0.5µA |
| Breakdown Voltage (Min) | 13.3V @ 1mA: guaranteed conduction onset under standardized test conditions |
| Clamping Voltage | 19.9V @ 20.1A: maximum voltage seen by protected circuit during rated surge |
| ESD Rating | ±30kV air / ±30kV contact per IEC61000-4-2: meets automotive-level ESD immunity requirements |
| Leakage Current | 0.5µA @ 12V: negligible standby power loss and minimal impact on high-impedance sensing nodes |
| Response Time | <1.0ns (unidirectional): ensures clamping activation before transient propagates into sensitive ICs |
Pinout & Package
Package: DO-219AA - ultra-low-profile (max height 0.75mm), molded green plastic case with matte tin-plated copper alloy leads; UL 94V-0 rated; moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection to protected circuit ground | Completes shunt path during overvoltage; must be routed with minimal inductance to system GND plane |
| Cathode | High-side connection to protected line (e.g., 12V rail) | Marked by cathode band; connects to node requiring clamping; polarity-critical for unidirectional operation |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse rating | Handles ISO 7637-2 Pulse 1 (–150V/50Ω) and Pulse 2a (50V/2Ω) without degradation |
| DO-219AA footprint | 0.81–1.20mm A dimension enables compact placement near connectors or IC pins with minimal board area |
| ±30kV ESD protection | Eliminates need for external ESD diodes in LIN/CAN node designs meeting ISO 10605 Class 4 |
| RoHS 3 & "Green" compliant | Halogen-free (<900ppm Br+Cl), antimony-free (<1000ppm), lead-free finish for automotive and industrial compliance |
| AEC-Q200 qualified variant available | Q-suffix versions undergo stress testing per AEC-Q200 Rev H for temperature cycling, humidity bias, and vibration |
Applications
| Automotive Body Control Module | LIN Bus Transceiver Protection |
|---|---|
Use Scenario: Protecting 12V supply rail feeding BCM microcontrollers and driver ICs against load dump and jump-start transients. IC Role / Device Role: Unidirectional TVS placed between battery input and local LDO regulator input. Use Value: Clamps 19.9V max during 20.1A surge, keeping downstream LDO input within safe operating range and preventing latch-up. |
Use Scenario: Safeguarding LIN physical layer transceivers (e.g., TLE7259) from ESD and cable discharge events. IC Role / Device Role: TVS connected between LIN bus line and chassis ground, with cathode to LIN. Use Value: Sub-1ns response and ±30kV ESD rating ensure transceiver survives direct contact discharge without functional interruption. |
| Industrial Sensor Interface | USB-C Power Delivery Line |
Use Scenario: Shielding 24V analog sensor inputs (e.g., pressure transducers) from field-induced surges in factory automation systems. IC Role / Device Role: TVS installed at connector entry point, shunting transients before signal conditioning op-amps. Use Value: 12V VRWM allows use on 24V systems with sufficient margin; 0.5µA leakage avoids offset errors in µA-level sensor currents. |
Use Scenario: Protecting USB-C VBUS line (5–20V) from hot-plug overshoot and ESD during mating/unmating. IC Role / Device Role: Unidirectional TVS placed between VBUS and GND, sized for 20V PD profile with headroom. Use Value: 19.9V clamping at 20.1A prevents overvoltage damage to USB-C controller and port power switches during fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Same DO-214AC package; 400W rating; higher clamping voltage (23.2V @ 17.2A); larger footprint | Less suitable for space-constrained automotive modules due to 3.5mm × 1.9mm vs. DO-219AA's 2.0mm × 1.2mm | Select when legacy SMA layout exists and lower capacitance is not required |
| SMF4L12CA | Bidirectional version; identical VRWM (12V), VBR (13.3V min), and clamping (19.9V); same DO-219AA package | Required only for AC-coupled or bidirectional signal lines (e.g., CAN FD differential pairs) | Choose only if protecting symmetric signals; unidirectional SMF4L12A-7 is optimal for DC rails |
Compared with SMAJ12A, SMF4L12A-7 offers 30% smaller board area and lower clamping voltage; versus SMF4L12CA, it provides tighter leakage control (0.5µA vs. 1.0µA) and eliminates unnecessary bidirectional conduction in DC applications.
Availability
SMF4L12A-7 is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, and USB-C power delivery systems requiring stable component supply across multi-year production cycles.
Supply support for SMF4L12A-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 TVS portfolio targeting automotive and industrial applications, engineered specifically for AEC-Q200 compliance, low-profile mounting, and robust ESD/transient immunity in harsh environments.
FAQ
What is the polarity configuration of SMF4L12A-7?
SMF4L12A-7 is a unidirectional TVS diode, with cathode denoted by a visible band on the DO-219AA package. It conducts only when the cathode is at a higher potential than the anode, making it suitable for DC rail protection where polarity is fixed. This differs from bidirectional variants like SMF4L12CA, which lack the band and conduct in both directions.
Can SMF4L12A-7 replace SMAJ12A in existing designs?
Yes, but with layout adaptation: SMF4L12A-7 uses DO-219AA (2.0mm × 1.2mm), while SMAJ12A uses DO-214AC (4.5mm × 2.7mm). The smaller footprint requires PCB pad redesign. Electrically, SMF4L12A-7 offers lower clamping (19.9V vs. 23.2V) and faster response (<1ns vs. ~1.5ns), improving protection margin in space-constrained applications.
Is SMF4L12A-7 qualified for automotive use?
The base SMF4L12A-7 is not AEC-Q200 qualified, but Diodes offers automotive-grade equivalents with Q-suffix (e.g., SMF4L12AQ-7), manufactured in IATF 16949-certified facilities and tested per AEC-Q200 Rev H. These variants include extended temperature screening (–55°C to +175°C), bias life testing, and PPAP documentation support.
How does the 0.5µA leakage current affect low-power circuits?
At 12V VRWM, SMF4L12A-7 draws only 0.5µA, making it compatible with battery-powered sensors and always-on microcontroller domains where standby current budgets are tight. This leakage is 5× lower than typical SMAJ-series devices and introduces negligible error in µA-range current-sense or high-impedance voltage-divider networks.
SMF4L12A-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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 20.1A
- 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
SMF4L12A-7 FAQ
1.How can I place an order for SMF4L12A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L12A-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 SMF4L12A-7 reliable?
The price and inventory of SMF4L12A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L12A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L12A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L12A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L12A-7?
SMF4L12A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L12A-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 SMF4L12A-7?
For technical support, including SMF4L12A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L12A-7 requirements.
6.How does Aetrix verify that SMF4L12A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L12A-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 SMF4L12A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L12A-7?
All SMF4L12A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L12A-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 SMF4L12A-7 part is unused and in its original packaging.
Return procedure for SMF4L12A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L12A-7 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 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…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
