My Inquiry
My Account
Taiwan Semiconductor Corporation SMA4S25AH
- Part No.:
- SMA4S25AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-128
- Datasheet:
-
SMA4S25AH.pdf
- Description:
- TVS DIODE 25VWM 40.6VC SOD128
- Quantity:
- Payment:
- Shipping:
Inventory:3,733
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMA4S25AH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in SOD-128 package, with 25V working stand-off voltage (VWM), 27.9–30.9V breakdown voltage (VBR), and 40.6V clamping voltage (VC) at 9.9A peak pulse current; used for overvoltage protection in automotive BLDC motor drives and battery management systems.
For engineers reviewing the SMA4S25AH datasheet, SMA4S25AH pinout, SMA4S25AH application, or SMA4S25AH equivalent, key selection criteria include unidirectional polarity, 175°C max junction temperature, AEC-Q101 qualification, 20°C/W junction-to-lead thermal resistance, and compatibility with 10/1000μs surge waveforms in space-constrained PCB layouts.
Technical Context
The SMA4S25AH operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its specified VBR range (27.9–30.9V at 1mA). It clamps transients to ≤40.6V at 9.9A (10/1000μs), limiting energy dissipation to 400W non-repetitive pulses while maintaining stable leakage (<1μA at 25V).
Designed for high-reliability automotive environments, it features glass-passivated junction, JESD201 Class 2 whisker resistance, moisture sensitivity level 1, and UL 94V-0 molding compound - all supporting operation across –55°C to +175°C junction temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 25 V - Maximum continuous reverse operating voltage before conduction begins |
| VBR min/max | 27.9 V / 30.9 V - Breakdown voltage range at 1 mA test current; defines turn-on threshold tolerance |
| VC @ IPPM | 40.6 V - Clamped voltage at 9.9 A peak pulse current; determines protected circuit's maximum transient stress |
| PPPM | 400 W - Peak pulse power handling capability under 10/1000 μs waveform; critical for surge immunity |
| TJ max | +175 °C - Maximum allowable junction temperature; enables use in under-hood automotive locations |
| RθJL | 20 °C/W - Junction-to-lead thermal resistance; supports thermal design with PCB copper pad heatsinking |
| Polarity | Unidirectional - Blocks forward current; only conducts during negative transients relative to cathode |
Pinout & Package
Package: SOD-128 surface-mount molded case with matte tin-plated leads, cathode band marking, and 0.028g mass. Complies with JEDEC MO-290 and IEC 60134 standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during clamping | Connected to protected line (e.g., battery rail); conducts when voltage exceeds VBR |
| Cathode | Current exit terminal during clamping | Connected to ground or lower-potential reference; marked by band on package body |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress requirements |
| Glass passivated junction | Enhances long-term stability and reduces parameter drift under humidity and thermal stress |
| VBR tempco | 0.095%/°C - Predictable voltage shift over temperature; simplifies system-level margining |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for eco-conscious manufacturing |
| Junction-to-lead RθJL | 20°C/W - Enables effective heat transfer to PCB copper pads without external heatsinks |
Applications
| BLDC Motor Drive Protection | Battery Management System (BMS) |
|---|---|
Use Scenario: Suppresses inductive kickback and load dump surges in 24V/36V BLDC motor control modules. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed across motor phase terminals or supply rails to clamp transients. Use Value: Limits voltage to ≤40.6V during 9.9A 10/1000μs surges, preventing gate oxide damage to MOSFETs and driver ICs. | Use Scenario: Protects cell monitoring ICs and communication interfaces from ESD and battery disconnect transients. IC Role / Device Role / Timing Role: Standoff-rated TVS on 25V battery pack input lines and CAN/LIN bus lines. Use Value: Maintains <1μA leakage at 25V VWM while clamping fast transients to safe levels for precision analog front-ends. |
| Automotive Lighting Control | Switching Mode Power Supply (SMPS) |
Use Scenario: Shields LED driver ICs and microcontrollers from load dump and ISO 7637-2 Pulse 5a/b events. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 25V auxiliary supply rail feeding lighting controllers. Use Value: Withstands 400W peak pulses and operates up to +175°C ambient, meeting under-hood thermal requirements. | Use Scenario: Safeguards secondary-side rectifiers and feedback circuits in 25V-output DC/DC converters. IC Role / Device Role / Timing Role: Secondary-rail TVS on output capacitor node to absorb switching noise and cross-regulation spikes. Use Value: Delivers consistent 40.6V clamping with <0.1% VBR drift/°C, ensuring predictable regulation loop behavior. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ25A | Lower PPPM (400W same), but higher VC = 43.0V at 9.2A; VBR = 27.8–30.7V; SOD-123 package | SOD-123 has lower thermal mass and higher RθJA (85°C/W vs. 62°C/W), reducing sustained surge capability | Select SMAJ25A only if board space is tighter and thermal derating is acceptable |
| SMBJ25A | Same VWM/VBR range, but higher PPPM (600W); VC = 43.0V at 13.8A; SMB package (larger footprint) | Larger SMB footprint allows better thermal dissipation but requires more PCB area | Choose SMBJ25A when higher single-pulse energy handling is required and layout permits larger package |
Compared with SMAJ25A and SMBJ25A, the SMA4S25AH offers optimized balance of 400W surge rating, 40.6V clamping, SOD-128 thermal performance (RθJL = 20°C/W), and AEC-Q101 qualification - making it preferred for space-constrained, thermally demanding automotive modules where unidirectional protection is sufficient.
Availability
SMA4S25AH is available at Aetrix Electronics and suitable for BLDC motor drives, battery management systems, automotive lighting control, and switching mode power supplies requiring stable component supply with automotive-grade reliability and traceable sourcing.
Supply support for SMA4S25AH 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 for industrial and automotive markets.
The SMA4SxxAH series is part of TSC's AEC-Q101-qualified TVS portfolio, engineered specifically for robust transient suppression in harsh automotive environments - including engine control units, body electronics, and electrified powertrain subsystems.
FAQ
What is the breakdown voltage range of the SMA4S25AH?
The SMA4S25AH has a guaranteed breakdown voltage (VBR) range of 27.9 V to 30.9 V at 1 mA test current, measured per JESD201 and verified across production lots. This range ensures reliable turn-on behavior in 25V nominal systems while accommodating process variation and temperature effects. The SMA4S25AH maintains this specification across its full operating temperature range of –55°C to +175°C.
Is the SMA4S25AH suitable for automotive applications?
Yes, the SMA4S25AH is AEC-Q101 qualified and designed for automotive use, including under-hood environments. It meets stringent requirements for temperature cycling, high-temperature reverse bias, and mechanical shock. Its 175°C max junction temperature, glass-passivated junction, and JESD201 Class 2 whisker resistance make the SMA4S25AH appropriate for BLDC motor drives, BMS, and lighting modules in passenger and commercial vehicles.
What is the clamping voltage of the SMA4S25AH at its rated peak pulse current?
The SMA4S25AH clamps to a maximum of 40.6 V at 9.9 A peak pulse current (IPPM) under the standard 10/1000 μs waveform. This value is guaranteed per datasheet specifications and reflects worst-case device behavior at TA = 25°C. The low clamping voltage ensures downstream components like MOSFETs and microcontrollers remain within safe operating limits during surge events.
Does the SMA4S25AH have unidirectional or bidirectional polarity?
The SMA4S25AH is a unidirectional TVS diode, meaning it conducts only during reverse-biased transients - i.e., when cathode voltage exceeds anode voltage. Its polarity is marked by a cathode band on the SOD-128 package body. This configuration provides optimal protection for DC rails where forward conduction is not required, such as battery inputs and SMPS outputs.
What is the thermal resistance from junction to lead (RθJL) for the SMA4S25AH?
The SMA4S25AH has a typical junction-to-lead thermal resistance (RθJL) of 20°C/W when mounted on a 5 mm × 5 mm copper pad test board. This low value enables efficient heat transfer from the silicon die to the PCB, supporting reliable operation at elevated ambient temperatures. The RθJL value is critical for calculating junction temperature rise during repetitive surge events or steady-state power dissipation.
SMA4S25AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- SOD-128
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 25V
- Voltage - Breakdown (Min):
- 27.9V
- Voltage - Clamping (Max) @ Ipp:
- 40.6V
- Current - Peak Pulse (10/1000µs):
- 9.9A
- 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:
- SOD-128
SMA4S25AH FAQ
1.How can I place an order for SMA4S25AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4S25AH 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 SMA4S25AH reliable?
The price and inventory of SMA4S25AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4S25AH is usually 5 days.
3.What payment methods are accepted for SMA4S25AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4S25AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4S25AH?
SMA4S25AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4S25AH 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 SMA4S25AH?
For technical support, including SMA4S25AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4S25AH requirements.
6.How does Aetrix verify that SMA4S25AH is sourced from the original manufacturer or authorized distributors?
All SMA4S25AH 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 SMA4S25AH meets industry standards.
7.What is the process for return or replacement of SMA4S25AH?
All SMA4S25AH units undergo pre-shipment inspection (PSI). If there is an issue with SMA4S25AH, 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 SMA4S25AH part is unused and in its original packaging.
Return procedure for SMA4S25AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA4S25AH 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
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
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…
