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Home > Products > Circuit Protection > Transient Voltage Suppressors (TVS) > TVS Diodes

Vishay General Semiconductor - Diodes Division T4F20AHM3/I

Name: T4F20AHM3/I
Brand: Vishay General Semiconductor - Diodes Division
SKU: T4F20AHM3/I
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: T4F20AHM3/I

Manufacturer:: Vishay General Semiconductor - Diodes Division

Category:: TVS Diodes

Package:: DO-219AB

Datasheet:: T4F20AHM3/I.pdf

Description:: LOW PROFILE OF 400W PAR TVS PROD

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Product details

Overview

T4F20AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor in the eSMP® Series, designed for automotive-grade overvoltage protection. It features a 20.0 V nominal breakdown voltage (V_BR), 17.1 V stand-off voltage (V_WM), 27.7 V maximum clamping voltage (V_C) at 14.4 A peak pulse current, 400 W peak pulse power (10/1000 μs), and operates up to +185 °C junction temperature - deployed on sensor signal lines and MOSFET gate drivers in engine control units.

For engineers reviewing the T4F20AHM3/I datasheet, T4F20AHM3/I pinout, T4F20AHM3/I application, or T4F20AHM3/I equivalent, key selection criteria include its AEC-Q101 qualification, SMF (DO-219AB) package compatibility, unidirectional polarity with cathode band marking, and thermal resistance R_thJM of 15–18 °C/W for high-reliability under-hood environments.

Technical Context

This TVS diode uses passivated anisotropic rectifier technology optimized for low leakage and stable clamping under repetitive transients. Its junction passivation enables operation at T_J = 185 °C and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak.

The device delivers 400 W peak pulse power with a 10/1000 μs waveform and exhibits a typical V_BR temperature coefficient of +0.082 %/°C, enabling predictable voltage shift across automotive temperature ranges without external compensation.

Key Specifications

Parameter	Value and Actual Design Meaning
V_BR (Nominal)	20.0 V - ensures reliable triggering above 17.1 V system stand-off voltage while avoiding false trips during normal 12 V rail ripple
V_C @ I_PPM	27.7 V - clamps induced surges to safe levels for downstream 30 V-rated ICs and MOSFETs
I_PPM	14.4 A - supports robust protection against ISO 7637-2 Pulse 1/2a/5a transients in 12 V automotive networks
P_PPM	400 W - sustains high-energy lightning-induced or load-dump surges without degradation
T_J max.	+185 °C - enables placement near hot components (e.g., power modules) without derating in under-hood ECUs
R_thJM	15–18 °C/W - provides efficient heat transfer to PCB copper pads, critical for sustained surge duty cycles

Pinout & Package

Package: SMF (DO-219AB) - low-profile, halogen-free, RoHS-compliant, AEC-Q101 qualified surface-mount case with matte tin-plated leads and cathode band marking.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Current entry terminal during reverse-biased clamping	Connected to protected line (e.g., sensor output); forms clamping path to ground when transient exceeds V_WM
Cathode	Current exit terminal during clamping; marked by color band	Connected to system ground or low-impedance return path; defines unidirectional conduction direction

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive electronics per stress test requirements including HTGB, HTRB, and temperature cycling
Junction passivation	Enables stable leakage < 1.0 μA at V_WM and T_J = 150 °C, reducing false triggers in high-temp environments
MSL Level 1 rating	Allows unlimited floor life and single-reflow processing at 260 °C peak without moisture-related popcorning
eSMP® low-profile design	Height ≤ 1.3 mm enables use in space-constrained modules such as transmission control units and ADAS camera housings

Applications

Automotive Sensor Protection	Engine Control Unit (ECU) Power Input
Use Scenario: Protecting analog output lines of pressure, temperature, and position sensors exposed to inductive switching noise in vehicle chassis. IC Role / Device Role / Timing Role: Unidirectional TVS clamping element placed directly at sensor connector interface to shunt transients before reaching ADC input stage. Use Value: Maintains signal integrity with < 1.0 μA leakage at 17.1 V, preventing offset errors in 12-bit sensor measurements.	Use Scenario: Safeguarding 12 V supply rails feeding microcontrollers and CAN transceivers in engine bay ECUs subjected to ISO 7637-2 load dump events. IC Role / Device Role / Timing Role: Primary front-end surge suppression device mounted at board edge, upstream of DC/DC converter input. Use Value: Clamps 400 W transients to 27.7 V within 1 ns response time, preserving downstream regulator input voltage limits.
Body Control Module (BCM) Signal Lines	Electric Power Steering (EPS) Motor Driver Interface
Use Scenario: Shielding LIN bus and wake-up lines in BCMs from ESD and relay coil flyback in door modules and lighting systems. IC Role / Device Role / Timing Role: Point-of-use protection on each LIN node, placed adjacent to transceiver IC to minimize trace inductance. Use Value: Delivers 14.4 A peak pulse current handling with 0.082 %/°C V_BR stability, ensuring consistent protection across -40 to +125 °C ambient.	Use Scenario: Guarding gate drive signals between MCU and high-side/low-side MOSFETs in EPS motor inverters exposed to motor commutation spikes. IC Role / Device Role / Timing Role: Bidirectional-capable layout not applicable; this unidirectional device protects only gate-to-source paths referenced to driver ground. Use Value: Withstands repeated 10/1000 μs surges up to 400 W while maintaining R_thJM ≤ 18 °C/W for thermal reliability during continuous steering assist cycles.

Automotive Sensor Protection

Engine Control Unit (ECU) Power Input

Use Scenario: Protecting analog output lines of pressure, temperature, and position sensors exposed to inductive switching noise in vehicle chassis.

IC Role / Device Role / Timing Role: Unidirectional TVS clamping element placed directly at sensor connector interface to shunt transients before reaching ADC input stage.

Use Value: Maintains signal integrity with < 1.0 μA leakage at 17.1 V, preventing offset errors in 12-bit sensor measurements.

Use Scenario: Safeguarding 12 V supply rails feeding microcontrollers and CAN transceivers in engine bay ECUs subjected to ISO 7637-2 load dump events.

IC Role / Device Role / Timing Role: Primary front-end surge suppression device mounted at board edge, upstream of DC/DC converter input.

Use Value: Clamps 400 W transients to 27.7 V within 1 ns response time, preserving downstream regulator input voltage limits.

Body Control Module (BCM) Signal Lines

Electric Power Steering (EPS) Motor Driver Interface

Use Scenario: Shielding LIN bus and wake-up lines in BCMs from ESD and relay coil flyback in door modules and lighting systems.

IC Role / Device Role / Timing Role: Point-of-use protection on each LIN node, placed adjacent to transceiver IC to minimize trace inductance.

Use Value: Delivers 14.4 A peak pulse current handling with 0.082 %/°C V_BR stability, ensuring consistent protection across -40 to +125 °C ambient.

Use Scenario: Guarding gate drive signals between MCU and high-side/low-side MOSFETs in EPS motor inverters exposed to motor commutation spikes.

IC Role / Device Role / Timing Role: Bidirectional-capable layout not applicable; this unidirectional device protects only gate-to-source paths referenced to driver ground.

Use Value: Withstands repeated 10/1000 μs surges up to 400 W while maintaining R_thJM ≤ 18 °C/W for thermal reliability during continuous steering assist cycles.

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMAJ20A	Same V_BR (20.0 V), but lower P_PPM = 400 W (same rating), higher V_C = 32.4 V, SMA package (larger footprint, higher R_thJA)	Less suitable for space-constrained AEC-Q101 designs due to larger SMA footprint and no MSL Level 1 guarantee	Select T4F20AHM3/I when board area is limited and MSL Level 1 reflow compliance is required.
1.5SMC20A	Same V_BR, but higher P_PPM = 1500 W, DO-214AB package, non-AEC-Q101, R_thJA ≈ 30 °C/W	Over-specified for most automotive signal-line protection; unsuitable for under-hood high-temp mounting	Choose T4F20AHM3/I for automotive-qualified, thermally efficient, low-profile protection where 400 W suffices.

Compared with SMAJ20A and 1.5SMC20A, the T4F20AHM3/I offers superior thermal performance (R_thJM ≤ 18 °C/W vs. >30 °C/W), guaranteed AEC-Q101 qualification, and MSL Level 1 process compatibility - making it optimal for compact, high-reliability automotive signal-line protection.

Availability

T4F20AHM3/I is available at Aetrix Electronics and suitable for automotive sensor protection, engine control unit (ECU) power input hardening, and body control module (BCM) signal line safeguarding requiring stable component supply across extended production lifecycles.

Supply support for T4F20AHM3/I 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, TVS devices, and optoelectronics with emphasis on reliability, efficiency, and automotive-grade qualification.

The eSMP® Series - including T4F20AHM3/I - was developed specifically for high-temperature, high-reliability automotive electronics, delivering AEC-Q101-compliant transient suppression in ultra-low-profile packages for next-generation ECU and ADAS modules.

FAQ

What is the breakdown voltage tolerance for T4F20AHM3/I?

The T4F20AHM3/I has a breakdown voltage (V_BR) range of 19.0 V (min) to 21.0 V (max) at 1.0 mA test current, with a nominal value of 20.0 V. This ±5 % tolerance ensures consistent clamping behavior across production lots while accommodating thermal drift via its +0.082 %/°C coefficient. The T4F20AHM3/I maintains this specification under full AEC-Q101 stress validation.

Is T4F20AHM3/I compatible with lead-free reflow soldering processes?

Yes, the T4F20AHM3/I is fully compatible with lead-free reflow soldering, meeting J-STD-020 MSL Level 1 with a maximum peak temperature of 260 °C. Its matte tin-plated terminals comply with JESD 22-B102, and the molding compound satisfies UL 94 V-0 flammability rating - all confirmed per the official Vishay document 87645 revision 14-Feb-2023 for the T4F20AHM3/I.

Does T4F20AHM3/I support bidirectional transient suppression?

No, the T4F20AHM3/I is unidirectional only, as explicitly stated in the Vishay datasheet. It protects against positive transients on the cathode side relative to anode (i.e., anode grounded). For bidirectional protection, a separate device or a dedicated bidirectional TVS such as the SMBJ20CA would be required - the T4F20AHM3/I does not provide symmetrical clamping.

What is the maximum clamping voltage of T4F20AHM3/I at its rated peak pulse current?

The T4F20AHM3/I has a maximum clamping voltage (V_C) of 27.7 V at its rated peak pulse current (I_PPM) of 14.4 A, measured using a 10/1000 μs waveform. This value is guaranteed across the full operating temperature range and is critical for ensuring protected ICs remain below their absolute maximum voltage ratings during surge events.

How does the thermal resistance of T4F20AHM3/I compare to standard SOD-123 devices?

The T4F20AHM3/I features R_thJM of 15–18 °C/W, significantly lower than typical SOD-123 devices (R_thJM > 30 °C/W), due to its enhanced SMF (DO-219AB) package copper slug construction. This allows the T4F20AHM3/I to sustain repeated 400 W surges with less junction temperature rise - a key advantage for automotive under-hood applications where ambient temperatures exceed 105 °C.

T4F20AHM3/I Specifications

Product attributes: Attribute value

Manufacturer:: Vishay General Semiconductor - Diodes Division

Package/Case:: DO-219AB

Series:: PAR®

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: 1

Bidirectional Channels:: -

Voltage - Reverse Standoff (Typ):: 17.1V

Voltage - Breakdown (Min):: 19V

Voltage - Clamping (Max) @ Ipp:: 27.7V

Current - Peak Pulse (10/1000µs):: 14.4A

Power - Peak Pulse:: 400W

Power Line Protection:: No

Applications:: -

Capacitance @ Frequency:: -

Operating Temperature:: -65°C ~ 185°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: DO-219AB (SMF)

T4F20AHM3/I FAQ

1.How can I place an order for T4F20AHM3/I through Aetrix?

Please submit a Request for Quotation (RFQ) for T4F20AHM3/I 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 T4F20AHM3/I reliable?

The price and inventory of T4F20AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T4F20AHM3/I is usually 5 days.

3.What payment methods are accepted for T4F20AHM3/I?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T4F20AHM3/I transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for T4F20AHM3/I?

T4F20AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your T4F20AHM3/I 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 T4F20AHM3/I?

For technical support, including T4F20AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T4F20AHM3/I requirements.

6.How does Aetrix verify that T4F20AHM3/I is sourced from the original manufacturer or authorized distributors?

All T4F20AHM3/I 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 T4F20AHM3/I meets industry standards.

7.What is the process for return or replacement of T4F20AHM3/I?

All T4F20AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with T4F20AHM3/I, 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 T4F20AHM3/I part is unused and in its original packaging.

Return procedure for T4F20AHM3/I:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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