My Inquiry
My Account
Taiwan Semiconductor Corporation SMAJ48A
- Part No.:
- SMAJ48A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ48A.pdf
- Description:
- TVS DIODE 48VWM 77.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,385
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ48A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 48 V working stand-off voltage (VWM), 53.3–58.9 V breakdown voltage (VBR), and clamps to ≤77.4 V at 5.2 A peak impulse current under 10/1000 µs waveform, delivering 400 W peak pulse power.
For engineers reviewing the SMAJ48A datasheet, SMAJ48A pinout, SMAJ48A application, or SMAJ48A equivalent, key selection criteria include clamping voltage margin relative to protected IC VMAX, leakage current (<5.2 µA @ 48 V), junction temperature range (–55°C to +150°C), and compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electronics.
Technical Context
The SMAJ48A operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology for stable breakdown and low leakage. Its fast response time (<1.0 ps from 0 V to VBR min) enables suppression of ESD and surge transients before sensitive downstream circuitry is stressed.
It is rated for 400 W peak pulse power (10/1000 µs), derated linearly above 25°C ambient per Fig.2, and supports steady-state power dissipation up to 1 W. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for high-reliability PCB mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 48 V - Maximum continuous reverse operating voltage before significant leakage; sets upper limit for protected rail voltage. |
| VBR @ IT=1 mA | 53.3–58.9 V - Breakdown threshold range; ensures reliable conduction onset during overvoltage events. |
| VC @ IPPM=5.2 A | ≤77.4 V - Clamping voltage under 10/1000 µs surge; defines worst-case voltage seen by downstream components. |
| IR @ VWM | ≤5.2 µA - Reverse leakage at stand-off voltage; negligible power loss and minimal impact on high-impedance circuits. |
| PPPM | 400 W - Peak pulse power handling (10/1000 µs); sufficient for ISO 7637-2 Pulse 1 (inductive load dump) and Pulse 2b (battery disconnect). |
| TJ Range | –55°C to +150°C - Full industrial/automotive junction temperature range; supports operation in engine bay or power supply environments. |
| Package | DO-214AC (SMA) - Standard surface-mount outline with cathode band marking; compatible with automated pick-and-place and reflow. |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Meets J-STD-002 solderability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-voltage return path; forms current sink during clamping. |
| Cathode | High-side input terminal | Connected to protected line (e.g., 48 V rail); conducts avalanche current when VIN exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity stress. |
| Fast response time <1.0 ps | Activates before most microsecond-scale transients propagate, protecting logic-level interfaces and power MOSFET gates. |
| ISO 7637-2 compliance | Validated for automotive load-dump (Pulse 2b) and inductive-switching (Pulse 1) immunity without external filtering. |
| Moisture sensitivity level 1 | Zero bake requirement prior to reflow; simplifies manufacturing and reduces risk of popcorning. |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS directives; suitable for green electronics production. |
Applications
| Switching Mode Power Supply (SMPS) | On-board DC/DC Converter |
|---|---|
Use Scenario: Protection of primary-side controller ICs and secondary-side synchronous rectifiers against flyback spikes and cross-conduction surges. IC Role / Device Role / Timing Role: Unidirectional TVS placed across input bulk capacitor or output rail to clamp transient overshoot during startup and load transients. Use Value: Limits voltage excursion to ≤77.4 V, preventing gate oxide rupture in 100 V-rated MOSFETs and ensuring stable feedback loop operation. | Use Scenario: Input rail protection in point-of-load (POL) converters powering FPGAs or ASICs in telecom infrastructure. IC Role / Device Role / Timing Role: Standoff-clamp element between 48 V backplane and DC/DC input, absorbing hot-swap and cable discharge events. Use Value: With ≤5.2 µA leakage at 48 V, it avoids loading high-impedance enable or sense lines while maintaining fast clamping response. |
| Automotive Body Control Module (BCM) | Industrial LED Driver |
Use Scenario: Protection of LIN bus transceivers and relay drivers subjected to battery load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional clamp on 12 V or 48 V auxiliary rail, coordinated with upstream fuse and downstream L-C filter. Use Value: Meets ISO 7637-2 Pulse 2b (12 V system) and Pulse 1 (48 V mild-hybrid), enabling single-device compliance without redesign. | Use Scenario: Overvoltage safeguard for constant-current LED strings powered by buck-boost drivers in street lighting systems. IC Role / Device Role / Timing Role: Parallel-connected TVS across output terminals to absorb lightning-induced surges on long outdoor wiring runs. Use Value: 400 W peak power rating sustains multiple 10/1000 µs surges without degradation, extending field life beyond 10 years. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ48CA | Bidirectional variant; symmetric VBR (53.3–58.9 V) in both polarities; higher IR (≤10 µA @ ±48 V). | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, CAN FD); not suitable for unidirectional DC rails. | Select SMAJ48CA only when bidirectional clamping is mandated by signal integrity or fault-mode analysis. |
| SMBJ48A | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; 600 W PPPM rating (10/1000 µs). | Preferred where higher surge margin is needed (e.g., outdoor power supplies), but requires PCB layout change due to larger footprint. | Choose SMBJ48A if system-level testing shows marginal margin with SMAJ48A; otherwise retain SMAJ48A for space-constrained designs. |
Compared with SMAJ48CA and SMBJ48A, the SMAJ48A provides optimal balance of compact DO-214AC footprint, 400 W surge capability, and ultra-low leakage-making it ideal for space-limited 48 V DC systems where unidirectional protection suffices and board area is premium.
Availability
SMAJ48A is available at Aetrix Electronics and suitable for switching mode power supplies, automotive body control modules, and industrial LED drivers requiring stable component supply with full traceability and lifecycle management.
Supply support for SMAJ48A 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, and power MOSFETs since 1979.
The SMAJ series was developed specifically for high-reliability, surface-mount transient suppression in automotive and industrial power systems-emphasizing low clamping ratio, AEC-Q200 readiness, and robust package integrity.
FAQ
What is the maximum clamping voltage of the SMAJ48A under standard test conditions?
The SMAJ48A has a maximum clamping voltage (VC) of 77.4 V when subjected to a 5.2 A peak impulse current with a 10/1000 µs waveform. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ48A maintains this clamping performance across its full operating temperature range, making it suitable for demanding environments like automotive under-hood applications.
Is the SMAJ48A suitable for bidirectional signal line protection?
No, the SMAJ48A is a unidirectional TVS diode and is not suitable for bidirectional signal line protection. It conducts only when the cathode is positive relative to the anode. For bidirectional applications such as RS-485, CAN, or USB data lines, the SMAJ48CA (bidirectional variant) must be used instead. Using SMAJ48A on AC-coupled or dual-polarity lines would result in forward conduction during negative half-cycles, potentially damaging the device or circuit.
Does the SMAJ48A meet automotive qualification standards?
While the SMAJ48A is not individually AEC-Q200 certified, it meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements-key surge immunity standards for automotive electronics. Its construction (glass-passivated junction, MSL Level 1, JESD201 Class 2 whisker resistance) aligns with automotive-grade reliability practices. System-level qualification per AEC-Q200 may still be required depending on end-application criticality and OEM specifications.
What is the reverse leakage current specification for the SMAJ48A at its working voltage?
The SMAJ48A exhibits a maximum reverse leakage current (IR) of 5.2 µA when biased at its 48 V working stand-off voltage (VWM) and tested at TA = 25°C. This low leakage ensures minimal power loss and no measurable impact on high-impedance monitoring or enable circuits. Leakage remains within specification across the full –55°C to +150°C junction temperature range, supporting stable operation in extreme thermal environments.
Can the SMAJ48A be used in parallel to increase surge current handling?
No, the SMAJ48A should not be used in parallel to increase surge current handling. Due to inherent VBR tolerance (53.3–58.9 V), paralleled units will not share current evenly-lower-VBR devices conduct first and absorb disproportionate energy, risking thermal runaway. For higher surge ratings, select a single device with appropriate PPPM (e.g., SMBJ48A at 600 W) or implement staged protection with upstream fusing and impedance matching.
SMAJ48A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 48V
- Voltage - Breakdown (Min):
- 53.3V
- Voltage - Clamping (Max) @ Ipp:
- 77.4V
- Current - Peak Pulse (10/1000µs):
- 5.2A
- 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)
SMAJ48A FAQ
1.How can I place an order for SMAJ48A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ48A 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 SMAJ48A reliable?
The price and inventory of SMAJ48A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ48A is usually 5 days.
3.What payment methods are accepted for SMAJ48A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ48A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ48A?
SMAJ48A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ48A 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 SMAJ48A?
For technical support, including SMAJ48A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ48A requirements.
6.How does Aetrix verify that SMAJ48A is sourced from the original manufacturer or authorized distributors?
All SMAJ48A 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 SMAJ48A meets industry standards.
7.What is the process for return or replacement of SMAJ48A?
All SMAJ48A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ48A, 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 SMAJ48A part is unused and in its original packaging.
Return procedure for SMAJ48A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ48A 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
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
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 …
