My Inquiry
My Account
Taiwan Semiconductor Corporation SMA4S33AH
- Part No.:
- SMA4S33AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-128
- Datasheet:
-
SMA4S33AH.pdf
- Description:
- TVS DIODE 33VWM 53.6VC SOD128
- Quantity:
- Payment:
- Shipping:
Inventory:34,985
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMA4S33AH from Taiwan Semiconductor is a unidirectional 400W transient voltage suppressor (TVS) diode in SOD-128 package, with 33 V working stand-off voltage (VWM), 36.9–40.8 V breakdown voltage (VBR) at 1 mA, and 53.6 V clamping voltage (VC) at 7.5 A peak pulse current; used for overvoltage protection in automotive BLDC motor drives and battery management systems.
For engineers reviewing the SMA4S33AH datasheet, SMA4S33AH pinout, SMA4S33AH application, or SMA4S33AH equivalent, key selection criteria include unidirectional polarity, 175°C max junction temperature, 20°C/W junction-to-lead thermal resistance, compliance with AEC-Q101, and suitability for 10/1000 µs surge waveforms in high-reliability power electronics.
Technical Context
This TVS diode operates as a unidirectional avalanche clamp, activated above its specified VBR to shunt transient energy away from sensitive downstream circuitry. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1 µA at VWM), while the SOD-128 package supports high thermal dissipation via copper pad mounting.
The device is rated for 400 W non-repetitive peak pulse power (10/1000 µs), with thermal performance defined by RθJL = 20°C/W and RθJA = 62°C/W on a 5 mm × 5 mm Cu pad PCB. It meets JESD201 Class 2 whisker resistance and J-STD-020 moisture sensitivity Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 36.9 V / 40.8 V @ 1 mA - verified breakdown range ensuring reliable turn-on margin |
| VC @ IPPM | 53.6 V @ 7.5 A - clamping voltage during 10/1000 µs surge, limiting stress on protected ICs |
| PPPM | 400 W - peak pulse power handling capability under standardized surge waveform |
| TJ max | +175 °C - enables operation in under-hood automotive environments and high-power SMPS |
| RθJL | 20 °C/W - low thermal resistance from junction to lead supports efficient heat transfer to PCB |
| Polarity | Unidirectional - provides reverse-biased surge suppression only; requires correct orientation in circuit |
Pinout & Package
Package: SOD-128 - surface-mount, flat-lead, unidirectional diode package with cathode band marking; dimensions per Taiwan Semiconductor outline drawing; compatible with standard reflow profiles and J-STD-002 solderability requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional TVS configuration |
| Cathode | Reverse-blocking / clamping terminal | Connected to protected line (e.g., 33 V rail); conducts when reverse voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness |
| Glass-passivated junction | Ensures stable VBR tolerance and low IR drift over lifetime and temperature |
| VBR tempco | 0.095 %/°C - predictable voltage shift across -55°C to +175°C operating range |
| Halogen-free & RoHS | Complies with IEC 61249-2-21 and EU RoHS Directive for environmentally constrained applications |
| J-STD-020 MSL Level 1 | Zero floor life limitation - can be stored indefinitely at ≤30°C/85% RH without baking |
Applications
| Automotive BLDC Motor Control | On-Board Charger (OBC) Input Stage |
|---|---|
Use Scenario: Protection of gate drivers and MCU inputs against load-dump and inductive switching transients in 12 V/24 V automotive motor control modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed across motor phase lines or supply rails to clamp spikes up to 400 W. Use Value: Prevents latch-up or permanent damage to SiC MOSFET drivers by limiting VC to 53.6 V during 10/1000 µs surges. | Use Scenario: Surge suppression at AC-DC front-end input of electric vehicle on-board chargers exposed to grid transients and coupling noise. IC Role / Device Role / Timing Role: Primary-level TVS on rectified DC bus to absorb line-to-line and line-to-ground surges before PFC stage. Use Value: Maintains system uptime by surviving repeated 400 W pulses without degradation, supported by 175°C TJ rating. |
| Battery Management System (BMS) | Industrial Switching Mode Power Supply |
Use Scenario: Overvoltage protection on cell monitor IC supply rails and communication lines (e.g., daisy-chain UART) in high-voltage battery packs. IC Role / Device Role / Timing Role: Localized clamping element adjacent to analog front-end inputs to limit transient-induced measurement errors. Use Value: Enables <1 µA blocking leakage at 33 V, preserving BMS quiescent current budget and signal integrity. | Use Scenario: Secondary-side output rail protection in telecom and industrial 48 V SMPS units subject to back-EMF and hot-swap events. IC Role / Device Role / Timing Role: Fast-response unidirectional clamp on regulated 33 V output to safeguard connected FPGAs and ADCs. Use Value: Delivers 53.6 V clamping at 7.5 A with 20°C/W RθJL, enabling compact thermal design on dense PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | Lower PPPM (400 W same), but higher VC (59.0 V @ 6.8 A); VBR 36.7–40.6 V; SOD-123 package | SOD-123 has higher RθJA (~80°C/W), limiting power handling in confined layouts | Prefer SMA4S33AH where board space allows SOD-128 and lower clamping voltage is critical |
| SMBG33A | Same VWM/VBR range; 600 W PPPM; SMB package; RθJL = 15°C/W; higher VF (4.5 V) | Larger footprint; better thermal performance but less suitable for ultra-thin automotive modules | Choose SMBG33A when higher surge margin and thermal headroom outweigh size constraints |
Compared with SMAJ33A and SMBG33A, the SMA4S33AH delivers the lowest clamping voltage (53.6 V) in its voltage class with AEC-Q101 qualification and industry-leading thermal resistance (20°C/W), making it optimal for space-constrained, high-reliability automotive and industrial power rails.
Availability
SMA4S33AH is available at Aetrix Electronics and suitable for automotive BLDC motor control, battery management systems, and industrial switching mode power supplies requiring stable component supply, AEC-Q101 compliance, and repeatable 400 W surge immunity.
Supply support for SMA4S33AH 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, and rectifiers, with global distribution and AEC-Q101 qualified product lines.
The SMA4SxxAH series was designed specifically for high-energy transient suppression in automotive and industrial power systems, emphasizing low clamping voltage, thermal robustness, and long-term reliability under harsh environmental stress.
FAQ
What is the breakdown voltage range for SMA4S33AH?
The SMA4S33AH has a guaranteed breakdown voltage (VBR) range of 36.9 V to 40.8 V at a test current of 1 mA, measured per the manufacturer's electrical specifications table. This range ensures consistent clamping behavior across production lots and supports robust design margins in 33 V system protection. The SMA4S33AH's tight VBR tolerance contributes to predictable surge response in safety-critical applications.
Is SMA4S33AH suitable for automotive applications?
Yes, the SMA4S33AH is AEC-Q101 qualified and rated for junction temperatures from –55°C to +175°C, making it suitable for under-hood and powertrain applications. Its glass-passivated junction, MSL Level 1 rating, and JESD201 Class 2 whisker resistance meet automotive reliability requirements. The SMA4S33AH is explicitly listed in TSC's documentation for use in automotive BLDC motor control and battery management systems.
What is the clamping voltage of SMA4S33AH at its rated peak pulse current?
The SMA4S33AH exhibits a maximum clamping voltage (VC) of 53.6 V at a peak pulse current (IPPM) of 7.5 A under the 10/1000 µs waveform condition. This value is measured and guaranteed per the manufacturer's datasheet, and defines the upper voltage limit imposed on protected circuitry during surge events. Lower VC directly improves system-level surge immunity for the SMA4S33AH compared to alternatives in the same voltage class.
Does SMA4S33AH have unidirectional or bidirectional polarity?
The SMA4S33AH is a unidirectional TVS diode, indicated by its single cathode band marking and specification of forward voltage (VF = 3.5 V @ 25 A). It suppresses transients only in the reverse direction - i.e., when the cathode is at higher potential than the anode - and must be oriented accordingly in the circuit. Bidirectional variants are not offered in the SMA4SxxAH family.
What is the thermal resistance from junction to lead (RθJL) for SMA4S33AH?
The SMA4S33AH has a typical junction-to-lead thermal resistance (RθJL) of 20°C/W when mounted on a 5 mm × 5 mm copper pad PCB, as specified in the Thermal Performance section of the datasheet. This low value enables effective heat transfer from the silicon die to the PCB copper, supporting sustained surge handling and extended operational life in thermally demanding environments. The SMA4S33AH's RθJL is a key differentiator versus smaller-package alternatives.
SMA4S33AH 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):
- 33V
- Voltage - Breakdown (Min):
- 36.9V
- Voltage - Clamping (Max) @ Ipp:
- 53.6V
- Current - Peak Pulse (10/1000µs):
- 7.5A
- 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:
- SOD-128
SMA4S33AH FAQ
1.How can I place an order for SMA4S33AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4S33AH 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 SMA4S33AH reliable?
The price and inventory of SMA4S33AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4S33AH is usually 5 days.
3.What payment methods are accepted for SMA4S33AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4S33AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4S33AH?
SMA4S33AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4S33AH 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 SMA4S33AH?
For technical support, including SMA4S33AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4S33AH requirements.
6.How does Aetrix verify that SMA4S33AH is sourced from the original manufacturer or authorized distributors?
All SMA4S33AH 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 SMA4S33AH meets industry standards.
7.What is the process for return or replacement of SMA4S33AH?
All SMA4S33AH units undergo pre-shipment inspection (PSI). If there is an issue with SMA4S33AH, 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 SMA4S33AH part is unused and in its original packaging.
Return procedure for SMA4S33AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA4S33AH 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…
