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Diodes Incorporated SMF4L70AQ-7
- Part No.:
- SMF4L70AQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L70AQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:4,545
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Product details
Overview
SMF4L70AQ from Diodes Incorporated is a unidirectional transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in automotive power rails and battery interfaces. It features a 70V working peak reverse voltage (VRWM), 77.8V minimum breakdown voltage (VBR), 113A maximum peak pulse current (IRSM), 12V clamping voltage (VC) at IRSM, and AEC-Q101 qualification for under-hood applications.
For engineers reviewing the SMF4L70AQ datasheet, SMF4L70AQ pinout, SMF4L70AQ application, or SMF4L70AQ equivalent, key selection criteria include clamping performance at 113A, unidirectional polarity for DC rail protection, DO-219AA package thermal resistance (RθJA = 96°C/W), and compliance with IEC61000-4-2 ±30kV contact/air discharge.
Technical Context
This TVS operates as a voltage-clamped shunt device triggered when transient voltage exceeds its 77.8V breakdown threshold, diverting up to 113A (10/1000µs waveform) while limiting downstream voltage to ≤12V. Its fast response time (<1.0ns) ensures protection before sensitive ICs experience overstress.
Designed for automotive-grade reliability, it delivers 400W peak pulse power dissipation, supports continuous operation up to +175°C junction temperature, and maintains <0.5μA reverse leakage at 70V VRWM - critical for low-quiescent-power battery systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 70V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin above 12V/24V automotive system nominal rails. |
| VBR (min) | 77.8V - Minimum voltage at which device enters avalanche conduction; guarantees reliable triggering above normal transients. |
| VC @ IRSM | 12V - Clamping voltage at 113A peak current; limits stress on downstream 12V-rated components during ISO 7637-2 pulse 5a/b events. |
| PPK | 400W - Peak pulse power handling (10/1000µs); enables robust protection against load dump and inductive switching surges. |
| IR @ VRWM | <0.5μA - Reverse leakage at rated standoff voltage; preserves battery life in always-on vehicle modules (e.g., telematics, alarm systems). |
| TJ Range | −55°C to +175°C - Extended junction temperature range certified per AEC-Q101; supports placement near engines or power converters. |
| ESD Rating | ±30kV contact / ±30kV air per IEC61000-4-2 - Full-system ESD immunity without external shielding or filtering layers. |
Pinout & Package
Package: DO-219AA - ultra-compact surface-mount plastic package (1.90mm × 2.80mm × 0.60mm height), matte tin-plated copper alloy leadframe, RoHS-compliant and halogen-free ("Green"), 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 maintain <1.0ns response. |
| Cathode (banded end) | High-side connection to protected line (e.g., battery+, VBUS) | Identified by molded cathode band; polarity-critical for unidirectional operation on positive DC rails. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood use including temperature cycling, mechanical shock, and humidity testing per IATF 16949 production controls. |
| DO-219AA footprint | Enables high-density PCB layout with 30% smaller area than SMA; compatible with standard SMT reflow profiles and automated optical inspection (AOI). |
| 12V clamping at 113A | Provides hard voltage limit during ISO 7637-2 Load Dump (pulse 5a) and Jump Start (pulse 5b), protecting CAN transceivers and microcontrollers. |
| ±30kV ESD immunity | Eliminates need for secondary ESD protection on USB, LIN, or sensor lines connected to same power domain. |
| Lead-free & halogen-free | Meets EU RoHS 3 (2015/863/EU) and automotive green material requirements; <900ppm Br+Cl, <1000ppm Sb. |
Applications
| Automotive Power Distribution | Battery Management Systems |
|---|---|
Use Scenario: Protection of 12V/24V main power bus against load dump, jump start, and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed upstream of DC-DC converters and power management ICs. Use Value: Limits transient voltage to ≤12V during 113A surges, preventing latch-up or gate oxide damage in downstream PMICs and MCUs. |
Use Scenario: Input protection for BMS front-end monitoring circuits connected directly to Li-ion or lead-acid battery terminals. IC Role / Device Role / Timing Role: Primary overvoltage clamp on battery sense lines and charger input paths. Use Value: Maintains <0.5μA leakage at 70V VRWM to avoid parasitic drain, while clamping ESD events before they corrupt cell voltage measurements. |
| Infotainment Power Rails | Telematics Control Units |
Use Scenario: Surge suppression on USB-C PD and HDMI power delivery lines in head units and display modules. IC Role / Device Role / Timing Role: Fast-response unidirectional clamp on VBUS and auxiliary power inputs. Use Value: Responds in <1.0ns to meet USB-IF ESD test requirements and prevents data corruption during hot-plug events. |
Use Scenario: Protection of LTE/GNSS module power inputs exposed to vehicle electrical noise and antenna coupling. IC Role / Device Role / Timing Role: First-line defense on 5V/12V supply pins feeding cellular modems and GPS receivers. Use Value: Withstands repeated 400W pulses without degradation, ensuring long-term reliability in always-connected fleet tracking hardware. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ70A | Higher clamping voltage (115V vs. 12V), lower peak current (32.6A), SMA package (larger, higher RθJA). | Not suitable for 12V rail protection due to excessive clamping; limited to >70V systems like industrial AC inputs. | Select only if VRWM ≥70V and board space allows SMA footprint. |
| SMCJ70A | Same VRWM but 150A IRSM rating and 135V VC; larger DO-214AB package with higher thermal mass. | Used where higher energy absorption is needed (e.g., alternator output), but over-spec'd for compact BMS designs. | Prefer for high-reliability engine control modules where derating margin >30% is required. |
Compared with SMAJ70A and SMCJ70A, SMF4L70AQ delivers superior clamping performance (12V vs. 115V/135V) in a 30% smaller package, making it optimal for space-constrained 12V automotive electronics where low VC and fast response are mandatory.
Availability
SMF4L70AQ is available at Aetrix Electronics and suitable for automotive power distribution, battery management systems, infotainment power rails, and telematics control units requiring stable component supply across extended temperature and high-surge environments.
Supply support for SMF4L70AQ 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, specializing in high-reliability protection, power management, and signal integrity solutions for automotive, industrial, and consumer markets.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for automotive power rail protection with emphasis on low clamping voltage, ultra-fast response, and PPAP-capable manufacturing in IATF 16949-certified facilities.
FAQ
What is the polarity configuration of SMF4L70AQ?
SMF4L70AQ is a unidirectional TVS diode, identified by a cathode band on the DO-219AA package. It conducts only during positive transients on the cathode side relative to anode, making it suitable for DC power line protection where polarity is fixed - such as 12V battery feeds or regulated 5V/3.3V rails.
How does SMF4L70AQ perform under high ambient temperatures?
At +125°C ambient, its peak pulse current rating derates to ~75A (per Figure 1 derating curve), while maintaining full AEC-Q101 qualification up to +175°C junction temperature. Its RθJA of 96°C/W requires minimal copper area for thermal management in typical automotive PCB layouts.
Can SMF4L70AQ replace older SMAJ70A devices in existing designs?
No - SMF4L70AQ has significantly lower clamping voltage (12V vs. 115V) and higher peak current (113A vs. 32.6A), so direct replacement would cause unintended conduction during normal operation. Redesign is required to verify system-level clamping behavior and layout inductance effects.
Is SMF4L70AQ compliant with automotive ESD standards beyond IEC61000-4-2?
Yes - it meets ISO 10605 (automotive ESD) with ±30kV contact discharge and supports system-level compliance with ISO 16750-2 (electrical loads) and ISO 7637-2 (transient immunity), verified through AEC-Q101 stress testing including HTOL, TCT, and HAST.
SMF4L70AQ-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):
- 70V
- Voltage - Breakdown (Min):
- 77.8V
- Voltage - Clamping (Max) @ Ipp:
- 113V
- Current - Peak Pulse (10/1000µs):
- 3.5A
- Power - Peak Pulse:
- 400W
- 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:
- DO-219AA
SMF4L70AQ-7 FAQ
1.How can I place an order for SMF4L70AQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L70AQ-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 SMF4L70AQ-7 reliable?
The price and inventory of SMF4L70AQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L70AQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L70AQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L70AQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L70AQ-7?
SMF4L70AQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L70AQ-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 SMF4L70AQ-7?
For technical support, including SMF4L70AQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L70AQ-7 requirements.
6.How does Aetrix verify that SMF4L70AQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L70AQ-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 SMF4L70AQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L70AQ-7?
All SMF4L70AQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L70AQ-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 SMF4L70AQ-7 part is unused and in its original packaging.
Return procedure for SMF4L70AQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L70AQ-7 Tags
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