My Inquiry
My Account
onsemi 1SMB43AT3
- Part No.:
- 1SMB43AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB43AT3.pdf
- Description:
- TVS DIODE 43VWM 69.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:8,232
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMB43AT3 from ON Semiconductor is a unidirectional 600 W transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 43 V working peak reverse voltage (VRWM), 69.4 V maximum clamping voltage (VC) at 8.6 A peak pulse current (IPP), and sub-1 ns response time. It is used to safeguard automotive ECUs, industrial power supplies, and telecom interface circuits against ESD and lightning-induced surges.
For engineers reviewing the 1SMB43AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to protected IC VMAX, VRWM alignment with steady-state operating voltage, surge current capability under 10/1000 µs waveform, and UL 497B recognition for isolated loop protection compliance.
Technical Context
The 1SMB43AT3 operates as a Zener-based avalanche clamp, triggered when reverse voltage exceeds its 47.8–52.8 V breakdown range (VBR @ 1 mA). Its low zener impedance and fast junction response enable effective suppression of transients up to 600 W (1 ms, 10×1000 µs waveform).
It is rated for 5.0 µA max reverse leakage at 43 V VRWM, exhibits 400 pF typical junction capacitance at 0 V bias (1 MHz), and maintains stable performance across −65 °C to +150 °C operating temperature range - critical for under-hood automotive and industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 43 V - Maximum continuous reverse operating voltage before clamping begins; must be ≥ circuit's DC/peak operating voltage. |
| VBR @ IT=1 mA | 47.8–52.8 V - Confirmed Zener breakdown window; ensures predictable turn-on threshold under standardized test conditions. |
| VC @ IPP=8.6 A | 69.4 V - Maximum clamped voltage during 10/1000 µs surge; defines worst-case stress on downstream components. |
| PPK | 600 W - Peak pulse power handling (1 ms); determines survivability against high-energy transients like ISO 7637-2 Pulse 5a. |
| Response Time | <1.0 ns - Junction-level switching speed; enables suppression before sensitive logic or analog circuitry is exposed to overvoltage. |
| ESD Rating | Class 3 (>16 kV HBM) - Validated robustness against human-body model electrostatic discharge events. |
| UL Recognition | UL 497B (QVGQ2, File #E210057) - Certified for use in isolated loop circuit protection, including telecom and process control interfaces. |
Pinout & Package
1SMB43AT3 is housed in an SMB (DO-214AA) surface-mount package (Case 403A), featuring a cathode-indicated polarity band and modified L-bend leads for enhanced solder joint reliability. The package is void-free, thermoset plastic with corrosion-resistant finish and Pb-free construction (G suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink terminal during forward conduction; grounded reference node in unidirectional TVS configuration. | Connected to system ground or low-impedance return path; establishes reference for clamping action. |
| Cathode | Protected line connection point; carries transient current into device during reverse overvoltage event. | Connected directly to the line being protected (e.g., 48 V rail, RS-485 bus); must be routed with minimal trace inductance. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power | Enables single-device protection against severe transients per ISO 7637-2 and IEC 61000-4-5 Level 4 without parallel staging. |
| 43 V VRWM with 69.4 V VC | Provides 26.4 V headroom above VRWM - sufficient margin to avoid false triggering while limiting downstream voltage stress. |
| UL 497B recognition | Validates suitability for safety-critical isolated loop applications (e.g., 4–20 mA sensor loops, PLC analog inputs) without additional certification effort. |
| <1 ns response time | Minimizes voltage overshoot during fast-rising transients (e.g., ESD, relay bounce), reducing risk of latch-up or gate oxide damage. |
| Pb-free Surmetic® package | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level (MSL) 1 rating for reflow compatibility. |
Applications
| Automotive Power Rail Protection | Industrial 24/48 V DC Supply Clamping |
|---|---|
Use Scenario: Protecting engine control unit (ECU) 48 V input against load dump and alternator ripple transients per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between battery rail and DC-DC converter input. Use Value: Limits transient voltage to ≤69.4 V, preventing overvoltage shutdown or damage to upstream PMICs rated for 70 V absolute maximum. |
Use Scenario: Safeguarding programmable logic controller (PLC) 48 V backplane against switching surges from solenoid drivers. IC Role / Device Role / Timing Role: Standoff protector mounted at power entry connector with <5 mm trace length to ground plane. Use Value: Absorbs 600 W pulses without degradation, maintaining system uptime in harsh factory environments where maintenance access is limited. |
| Telecom Isolated Loop Interface | Medical Equipment Signal Line Protection |
Use Scenario: Shielding 4–20 mA current loop transmitter outputs from induced surges in building automation wiring. IC Role / Device Role / Timing Role: UL 497B-certified TVS installed across loop terminals per ANSI/TIA-568-C.2 guidelines. Use Value: Meets isolation barrier integrity requirements while clamping common-mode transients up to 1 kV without compromising loop accuracy. |
Use Scenario: Protecting analog front-end inputs of patient monitoring devices connected to external sensors via long cables. IC Role / Device Role / Timing Role: Low-capacitance (400 pF) TVS placed adjacent to ADC input pins to minimize signal distortion. Use Value: Suppresses ESD events >16 kV (HBM) without introducing measurable offset or noise in sub-mV biomedical signal paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ43A | Same VRWM (43 V) and VC (69.4 V), but rated for 600 W with tighter VBR tolerance (47.8–50.3 V vs. 47.8–52.8 V); slightly lower Ctyp (385 pF). | Preferred where tighter breakdown consistency is required for precision clamping; identical footprint and mounting. | Select SMBJ43A if design requires reduced parametric spread in production lots or tighter thermal derating curves. |
| 1.5SMC43A | Higher package thermal resistance (RJA = 226 °C/W vs. 1SMB43AT3's 226 °C/W same, but larger SMC package offers better heat dissipation at board level). | Better suited for high-ambient-temperature environments (>105 °C) due to larger copper pad area and lower junction-to-board Rθ. | Choose 1.5SMC43A only when PCB layout allows SMC (DO-214AB) footprint and thermal management prioritizes long-duration surge endurance over space constraints. |
Compared with SMBJ43A and 1.5SMC43A, the 1SMB43AT3 delivers identical electrical clamping performance in a smaller SMB footprint, making it optimal for space-constrained automotive and industrial modules where UL 497B compliance and Pb-free assembly are mandatory.
Availability
1SMB43AT3 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial 48 V DC supply clamping, and telecom isolated loop interface applications requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for 1SMB43AT3 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The 1SMB43AT3 belongs to the SMB series of unidirectional TVS diodes engineered specifically for high-reliability overvoltage protection in harsh environments - emphasizing surge robustness, UL certification, and surface-mount manufacturability.
FAQ
What is the maximum clamping voltage of the 1SMB43AT3 under standard surge conditions?
The 1SMB43AT3 has a maximum clamping voltage (VC) of 69.4 V when subjected to its rated peak pulse current of 8.6 A under the standard 10/1000 µs waveform. This value is measured at TA = 25 °C and defines the upper voltage limit imposed on the protected circuit during transient events - critical for ensuring downstream ICs remain within their absolute maximum ratings.
Does the 1SMB43AT3 meet UL 497B requirements for isolated loop protection?
Yes, the 1SMB43AT3 is UL recognized under standard UL 497B (File #E210057, category QVGQ2) for use in isolated loop circuit protection. This certification covers validation of strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance - confirming its suitability for 4–20 mA loops, fieldbus interfaces, and other safety-isolated signal paths without requiring additional system-level testing.
What is the reverse leakage current specification for the 1SMB43AT3 at its working voltage?
The 1SMB43AT3 specifies a maximum reverse leakage current (IR) of 5.0 µA at its working peak reverse voltage (VRWM) of 43 V and ambient temperature of 25 °C. This low leakage ensures minimal power loss and signal interference in always-on monitoring circuits, such as battery-backed sensors or continuously powered industrial controllers.
Can the 1SMB43AT3 be used in automotive under-hood applications?
Yes, the 1SMB43AT3 is qualified for operation from −65 °C to +150 °C and is widely deployed in automotive under-hood applications, including engine control units and body control modules. Its 600 W surge rating, UL 497B recognition, and Pb-free Surmetic® package meet AEC-Q101 stress test requirements when applied per recommended PCB layout guidelines (e.g., short traces, thermal relief pads).
How does the junction capacitance of the 1SMB43AT3 affect high-speed signal line protection?
The 1SMB43AT3 exhibits 400 pF typical junction capacitance at 0 V bias (1 MHz), which makes it unsuitable for direct placement on high-speed data lines (e.g., USB 2.0, CAN FD, or Ethernet). It is optimized for DC power rails and low-frequency analog/sensor lines where bandwidth impact is negligible - for signal integrity-critical paths, lower-capacitance TVS arrays or specialized ESD protection devices should be selected instead of the 1SMB43AT3.
1SMB43AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 69.4V
- Current - Peak Pulse (10/1000µs):
- 8.6A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 400pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB43AT3 FAQ
1.How can I place an order for 1SMB43AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB43AT3 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 1SMB43AT3 reliable?
The price and inventory of 1SMB43AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB43AT3 is usually 5 days.
3.What payment methods are accepted for 1SMB43AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB43AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB43AT3?
1SMB43AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB43AT3 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 1SMB43AT3?
For technical support, including 1SMB43AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB43AT3 requirements.
6.How does Aetrix verify that 1SMB43AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB43AT3 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 1SMB43AT3 meets industry standards.
7.What is the process for return or replacement of 1SMB43AT3?
All 1SMB43AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB43AT3, 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 1SMB43AT3 part is unused and in its original packaging.
Return procedure for 1SMB43AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB43AT3 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…
