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

Taiwan Semiconductor Corporation P4SMA6.8

Name: P4SMA6.8
Brand: Taiwan Semiconductor Corporation
SKU: P4SMA6.8
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: P4SMA6.8

Manufacturer:: Taiwan Semiconductor Corporation

Category:: TVS Diodes

Package:: DO-214AC, SMA

Datasheet:: P4SMA6.8.pdf

Description:: 400W, 6.8V, 10%, UNIDIRECTIONAL,

Quantity:: RFQ Add To RFQ list

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Inventory:2,754

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Product details

Overview

P4SMA6.8 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping ESD and surge transients in low-voltage DC power rails. It features a 6.12–7.48 V breakdown voltage (V_BR), 5.5 V working stand-off voltage (V_WM), 10.8 V maximum clamping voltage (V_C) at 38 A peak pulse current, 400 W peak pulse power rating (10/1000 µs), and <1 µA reverse leakage at V_WM, making it suitable for protecting 5 V USB, adapter, and SMPS input stages.

For engineers reviewing the P4SMA6.8 datasheet, P4SMA6.8 pinout, P4SMA6.8 application, or P4SMA6.8 equivalent, key selection criteria include its unidirectional polarity, DO-214AC mechanical compatibility, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, 0.057 %/°C V_BR temperature coefficient, and 150 °C max junction temperature - all critical for automotive and industrial power rail protection design.

Technical Context

The P4SMA6.8 operates as a unidirectional avalanche diode with glass-passivated junction, optimized for fast transient suppression (<1.0 ps response time). Its electrical behavior follows IEEE C62.35 standards, with breakdown tested at 10 mA IT and clamping defined under 10/1000 µs waveform per REA.

It is rated for 40 A non-repetitive forward surge (8.3 ms half-sine), supports −55 °C to +150 °C operating and storage ranges, and meets J-STD-020 moisture sensitivity level 1 - enabling reflow-compatible automated placement without preconditioning.

Key Specifications

Parameter	Value and Actual Design Meaning
V_BR @ I_T=10 mA	6.12–7.48 V: Ensures reliable avalanche conduction onset above 5.5 V system rail while avoiding false triggering
V_WM	5.5 V: Maximum continuous reverse voltage before significant leakage; matches 5 V logic and USB power domains
V_C @ I_PPM=38 A	10.8 V: Clamped voltage during 400 W surge; keeps downstream ICs below absolute maximum ratings
I_R @ V_WM	<1000 µA: Low standby leakage preserves efficiency in battery-powered or always-on circuits
P_PPM	400 W (10/1000 µs): Sustains high-energy transients common in automotive load-dump and inductive switching
T_J_MAX	+150 °C: Enables operation in under-hood or enclosed power supply environments without derating
Package	DO-214AC (SMA): Standardized SMT footprint compatible with IPC-7351B land patterns and pick-and-place tooling

Pinout & Package

DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, cathode band marking polarity, UL 94V-0 flammability rating, and 0.060 g typical weight. Compliant with JESD201 Class 2 whisker resistance and J-STD-002 solderability.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry / Surge return path	Connected to ground or low-impedance return plane; completes clamping loop during transient events
Cathode	Reverse-biased terminal / Protected line connection	Connected to the line being protected (e.g., 5 V rail); conducts when voltage exceeds V_BR

Key Features

Feature	Design Value
Glass passivated junction	Ensures stable V_BR tolerance and long-term reliability under thermal cycling and humidity stress
Fast response time <1.0 ps	Clamps ESD events before sensitive ICs experience overstress, meeting IEC 61000-4-2 Level 4 requirements
ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b)	Validated for automotive 12 V system immunity against coupled transients including load dump and alternator ripple
RoHS & halogen-free	Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for environmentally compliant manufacturing
MSL Level 1	Zero floor life limitation; can be mounted directly after tape-and-reel delivery without baking

Applications

Switching Mode Power Supply (SMPS)	USB Power Adapter
Use Scenario: Input rectifier output or post-regulator rail in AC/DC adapters subject to lightning-induced surges and line transients. IC Role / Device Role: Unidirectional TVS diode placed across DC bus to clamp overvoltage spikes before they reach primary-side controller or secondary-side synchronous rectifier. Use Value: Limits transient voltage to ≤10.8 V at 38 A, preventing latch-up or gate oxide damage in MOSFETs and PWM controllers operating near 5–12 V rails.	Use Scenario: Protection of 5 V USB Type-A/C VBUS lines against ESD and hot-plug induced overshoot. IC Role / Device Role: Standoff-clamp TVS on VBUS path, positioned between connector and USB PD controller or load switch. Use Value: With 5.5 V V_WM, it remains fully blocking during normal 4.75–5.25 V operation while clamping ESD >8 kV (contact) to safe levels per IEC 61000-4-2.
On-board DC/DC Converter	LED Driver Input Stage
Use Scenario: Input protection for point-of-load (POL) converters in industrial PLCs where 24 V bus may experience inductive kickback. IC Role / Device Role: Primary-side transient suppressor on VIN pin of buck regulator ICs such as LM2678 or MP2451. Use Value: 400 W peak power rating handles repetitive 10/1000 µs pulses up to 38 A, sustaining converter uptime during factory equipment switching noise.	Use Scenario: Input filtering for constant-current LED drivers in streetlight or signage systems exposed to outdoor surge environments. IC Role / Device Role: First-line defense on driver input terminals, shunting surge energy away from bridge rectifier and electrolytic bulk capacitor. Use Value: 150 °C T_J_MAX and DO-214AC thermal mass enable stable operation in sealed enclosures with ambient temperatures up to 85 °C.

Switching Mode Power Supply (SMPS)

USB Power Adapter

Use Scenario: Input rectifier output or post-regulator rail in AC/DC adapters subject to lightning-induced surges and line transients.

IC Role / Device Role: Unidirectional TVS diode placed across DC bus to clamp overvoltage spikes before they reach primary-side controller or secondary-side synchronous rectifier.

Use Value: Limits transient voltage to ≤10.8 V at 38 A, preventing latch-up or gate oxide damage in MOSFETs and PWM controllers operating near 5–12 V rails.

Use Scenario: Protection of 5 V USB Type-A/C VBUS lines against ESD and hot-plug induced overshoot.

IC Role / Device Role: Standoff-clamp TVS on VBUS path, positioned between connector and USB PD controller or load switch.

Use Value: With 5.5 V V_WM, it remains fully blocking during normal 4.75–5.25 V operation while clamping ESD >8 kV (contact) to safe levels per IEC 61000-4-2.

On-board DC/DC Converter

LED Driver Input Stage

Use Scenario: Input protection for point-of-load (POL) converters in industrial PLCs where 24 V bus may experience inductive kickback.

IC Role / Device Role: Primary-side transient suppressor on VIN pin of buck regulator ICs such as LM2678 or MP2451.

Use Value: 400 W peak power rating handles repetitive 10/1000 µs pulses up to 38 A, sustaining converter uptime during factory equipment switching noise.

Use Scenario: Input filtering for constant-current LED drivers in streetlight or signage systems exposed to outdoor surge environments.

IC Role / Device Role: First-line defense on driver input terminals, shunting surge energy away from bridge rectifier and electrolytic bulk capacitor.

Use Value: 150 °C T_J_MAX and DO-214AC thermal mass enable stable operation in sealed enclosures with ambient temperatures up to 85 °C.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMBJ6.8A	600 W rating, 6.46–7.14 V V_BR, DO-214AA (SMB) package - larger footprint and higher clamping (11.2 V)	Better suited for higher-energy transients but requires PCB layout change due to larger body and pad spacing	Select SMBJ6.8A only if system-level testing shows P4SMA6.8's 400 W rating is insufficient for worst-case ISO 7637-2 Pulse 5a events
1.5SMC6.8A	1500 W rating, 6.46–7.14 V V_BR, DO-214AB (SMC) package - significantly larger, higher thermal mass, 10.5 V V_C	Used in main board-level protection where space allows and peak surge energy exceeds 400 W	Choose 1.5SMC6.8A when protecting upstream distribution nodes rather than individual subsystem rails

Compared with SMBJ6.8A and 1.5SMC6.8A, P4SMA6.8 offers optimal balance of compact DO-214AC size, 400 W capability, and 5.5 V V_WM - making it ideal for space-constrained, cost-sensitive 5 V rail protection where full 600–1500 W headroom is unnecessary.

Availability

P4SMA6.8 is available at Aetrix Electronics and suitable for switching mode power supplies, USB power adapters, and on-board DC/DC converters requiring stable component supply with consistent parametric performance and RoHS-compliant sourcing.

Supply support for P4SMA6.8 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q200 qualified product lines.

The P4SMA series is part of TSC's surface-mount TVS portfolio engineered specifically for high-reliability, high-volume industrial and automotive power rail protection - emphasizing robust surge handling, tight V_BR tolerance, and automated assembly compatibility.

FAQ

What is the polarity configuration of the P4SMA6.8?

The P4SMA6.8 is a unidirectional TVS diode, marked with a cathode band indicating the cathode terminal. It conducts in reverse bias above its breakdown voltage and blocks forward current up to 3.5 V at 25 A. This polarity is confirmed by its listing in the "Unidirectional" column of TSC's P4SMA6.8(A)–P4SMA200(A) datasheet revision S2102 and its absence from bidirectional suffix tables (e.g., P4SMA6.8C).

Does the P4SMA6.8 meet automotive transient immunity standards?

Yes, the P4SMA6.8 meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements as explicitly stated in the FEATURES section of the official TSC datasheet (S2102). Its 400 W peak pulse power rating and 10.8 V clamping voltage at 38 A ensure compliance with these standardized test waveforms for 12 V vehicle electrical systems.

What is the maximum clamping voltage of the P4SMA6.8 under surge conditions?

The maximum clamping voltage (V_C) of the P4SMA6.8 is 10.8 V at 38 A peak pulse current (I_PPM) under the standard 10/1000 µs waveform. This value is specified in the ELECTRICAL SPECIFICATIONS table for P4SMA6.8 and defines the upper voltage limit imposed on protected circuitry during a 400 W transient event.

Can the P4SMA6.8 be used in bidirectional signal line protection?

No, the P4SMA6.8 is unidirectional and not suitable for bidirectional signal line protection. For bidirectional applications, TSC specifies variants with "C" or "CA" suffixes (e.g., P4SMA6.8C), which have symmetrical breakdown characteristics in both directions. Using P4SMA6.8 on AC or differential signal lines would result in forward conduction during half-cycles and potential failure.

What is the moisture sensitivity level (MSL) and reflow profile compatibility of the P4SMA6.8?

The P4SMA6.8 has a moisture sensitivity level (MSL) of Level 1 per J-STD-020, meaning it has unlimited floor life and does not require dry-packaging or baking prior to reflow soldering. It is fully compatible with standard lead-free reflow profiles (e.g., JEDEC J-STD-020), supporting peak temperatures up to 260 °C without degradation.

P4SMA6.8 Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Package/Case:: DO-214AC, SMA

Series:: P4SMA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: 1

Bidirectional Channels:: -

Voltage - Reverse Standoff (Typ):: 5.5V

Voltage - Breakdown (Min):: 6.12V

Voltage - Clamping (Max) @ Ipp:: 10.8V

Current - Peak Pulse (10/1000µs):: 38A

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)

P4SMA6.8 FAQ

1.How can I place an order for P4SMA6.8 through Aetrix?

Please submit a Request for Quotation (RFQ) for P4SMA6.8 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 P4SMA6.8 reliable?

The price and inventory of P4SMA6.8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P4SMA6.8 is usually 5 days.

3.What payment methods are accepted for P4SMA6.8?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P4SMA6.8 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for P4SMA6.8?

P4SMA6.8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your P4SMA6.8 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 P4SMA6.8?

For technical support, including P4SMA6.8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P4SMA6.8 requirements.

6.How does Aetrix verify that P4SMA6.8 is sourced from the original manufacturer or authorized distributors?

All P4SMA6.8 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 P4SMA6.8 meets industry standards.

7.What is the process for return or replacement of P4SMA6.8?

All P4SMA6.8 units undergo pre-shipment inspection (PSI). If there is an issue with P4SMA6.8, 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 P4SMA6.8 part is unused and in its original packaging.

Return procedure for P4SMA6.8:

1.Submit a request within 90 days.

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

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