My Inquiry
My Account
onsemi 1SMB7.5AT3
- Part No.:
- 1SMB7.5AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB7.5AT3.pdf
- Description:
- TVS DIODE 7.5VWM 12.9VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,431
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMB7.5AT3 from ON Semiconductor is a unidirectional 600 W peak power TVS diode designed for transient overvoltage protection in DC power rails and signal lines. It features a 7.5 V working peak reverse voltage (VRWM), 12.9 V clamping voltage (VC) at 46.5 A peak pulse current (IPP), and sub-1 ns response time. It is used in automotive power supply inputs, industrial sensor interfaces, and medical equipment front-end protection circuits.
For engineers reviewing the 1SMB7.5AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC margin relative to protected IC absolute maximum ratings, surge current capability under IEC 61000-4-5 waveforms, and UL 497B recognition for isolated loop safety compliance.
Technical Context
The 1SMB7.5AT3 operates as a Zener-based avalanche clamp, triggered when reverse voltage exceeds its 8.33–9.21 V breakdown range (VBR @ IT = 1.0 mA). Its low zener impedance and fast junction response enable effective suppression of ESD (≥16 kV HBM) and lightning-induced surges without latch-up or thermal runaway.
It is rated for 600 W non-repetitive peak power (10/1000 µs waveform), with thermal resistance of 226 °C/W (junction-to-ambient) on FR-4 board and 40 °C/W (junction-to-lead), requiring careful PCB copper area design to sustain repeated transients. The device is inherently unidirectional and polarity-marked with cathode band.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 7.5 V - Maximum continuous reverse operating voltage before clamping begins; must be ≥ nominal DC rail voltage. |
| VBR (min/typ/max) | 8.33 / 8.77 / 9.21 V @ 1.0 mA - Confirmed Zener breakdown threshold defining turn-on precision and tolerance stack-up. |
| VC @ IPP | 12.9 V @ 46.5 A - Clamped voltage during 10/1000 µs surge; determines maximum stress on downstream components. |
| PPK | 600 W @ 1 ms - Peak surge energy handling capacity; defines immunity level against IEC 61000-4-5 Level 4 events. |
| IR @ VRWM | 100 µA - Reverse leakage at rated working voltage; ensures minimal standby power loss in battery-powered systems. |
| Response Time | < 1.0 ns - Junction-level switching speed; enables protection before sensitive logic or analog circuitry is overstressed. |
| UL Recognition | UL 497B QVGQ2 - Certified for isolated loop circuit protection; validates construction, flammability, and endurance per safety standard. |
Pinout & Package
1SMB7.5AT3 is housed in the SMB (DO-214AA) surface-mount package (Case 403A), featuring a modified L-bend lead form for enhanced solder joint reliability and thermal conduction. Cathode is marked by a distinct polarity band on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or lowest potential node; forms return path for clamped surge current. |
| Cathode | High-side transient input terminal | Connected to protected line (e.g., +12 V rail); voltage referenced to anode during clamping event. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W Peak Power Rating | Supports robust protection against IEC 61000-4-5 4th-level surges (4 kV line-earth) without degradation. |
| UL 497B Recognition | Validated for use in safety-critical isolated loop applications including telecom and medical isolation barriers. |
| ESD Robustness | Class 3 HBM rating (>16 kV) ensures immunity to handling and system-level ESD events per ANSI/ESDA JS-001. |
| Low Clamping Ratio | VC/VRWM = 1.72 - Tight ratio minimizes overvoltage margin required for protected ICs' absolute maximum ratings. |
| Pb-Free Construction | RoHS-compliant (1SMB7.5AT3G suffix) with compatible reflow profiles up to 260°C for 10 s. |
Applications
| Automotive Power Input Protection | Industrial Sensor Signal Line Clamp |
|---|---|
Use Scenario: 12 V battery-fed ECUs exposed to load dump (ISO 7637-2 Pulse 5a) and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power input and bulk capacitor to clamp surges before reaching PMIC or MCU. Use Value: Limits voltage to ≤12.9 V during 46.5 A transients, preventing damage to 16 V-rated input stages while maintaining UL 497B compliance. |
Use Scenario: 4–20 mA current loop sensors in factory automation subject to cable-induced surges and ESD. IC Role / Device Role / Timing Role: TVS mounted at connector entry point to shunt transients before signal conditioning op-amps or ADC inputs. Use Value: Sub-1 ns response ensures clamping occurs before 100 ns ESD pulses reach sensitive analog front-end, preserving measurement integrity. |
| Medical Equipment Isolated Supply Rail | AC-DC Adapter Output Protection |
Use Scenario: Secondary-side 5 V/3.3 V rails in UL-certified medical power supplies feeding isolated patient-monitoring circuits. IC Role / Device Role / Timing Role: UL 497B-recognized TVS on isolated output to meet creepage/clearance and surge immunity requirements. Use Value: Enables full compliance with IEC 60601-1 clause 8.8.3 for transient overvoltage protection without adding external isolation components. |
Use Scenario: Output of wall-mounted AC-DC adapters powering consumer electronics, subject to mains-borne surges and hot-plug events. IC Role / Device Role / Timing Role: Final-stage TVS on DC output to protect connected devices from adapter internal failure or external line transients. Use Value: 600 W rating sustains multiple 10/1000 µs surges without parametric shift, ensuring long-term reliability in high-volume OEM power supplies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ7.5A | Same SMB package, identical VRWM (7.5 V) and VC (12.9 V), but rated for 600 W with tighter VBR tolerance (8.33–8.77 V min–max vs. 8.33–9.21 V). | Preferred where tighter breakdown consistency is required across temperature and production lots. | Select SMBJ7.5A if VBR distribution control is critical for margin-limited designs; otherwise 1SMB7.5AT3 offers validated UL 497B recognition. |
| 1.5SMC7.5A | Larger SMC (DO-214AB) package, same electrical specs but higher thermal mass (RJA = 180 °C/W vs. 226 °C/W) and 1500 W peak rating. | Suitable for high-reliability industrial systems requiring extended surge endurance or board-level thermal derating headroom. | Choose 1.5SMC7.5A only when PCB layout allows larger footprint and higher surge repetition rate is needed; 1SMB7.5AT3 optimizes space-constrained designs. |
Compared with SMBJ7.5A, 1SMB7.5AT3 provides broader VBR tolerance but unique UL 497B certification for isolated loops; versus 1.5SMC7.5A, it trades surge headroom for compact SMB footprint and lower profile-critical for thin-profile consumer adapters and automotive modules.
Availability
1SMB7.5AT3 is available at Aetrix Electronics and suitable for automotive power inputs, industrial sensor interfaces, medical isolated supplies, and AC-DC adapter outputs requiring stable component supply, RoHS compliance, and UL safety recognition.
Supply support for 1SMB7.5AT3 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 power applications.
The 1SMB7.5AT3 belongs to the SMB series of unidirectional TVS diodes engineered for high-energy transient suppression in cost-sensitive, high-volume applications where reliability, safety certification, and surface-mount manufacturability are essential.
FAQ
What is the clamping voltage of the 1SMB7.5AT3 under maximum surge conditions?
The 1SMB7.5AT3 clamps to 12.9 V at its rated peak pulse current of 46.5 A (10/1000 µs waveform). This value is guaranteed per datasheet Table on page 3 and represents the maximum voltage seen by downstream circuitry during a worst-case transient. Designers must ensure all protected components have absolute maximum ratings exceeding 12.9 V to avoid damage. The 1SMB7.5AT3 achieves this clamping with low dynamic impedance and sub-1 ns response.
Does the 1SMB7.5AT3 meet UL safety standards for isolated circuits?
Yes, the 1SMB7.5AT3 carries UL 497B recognition (File #E210057, category QVGQ2) specifically for isolated loop circuit protection. This certification covers dielectric withstand, surge endurance, temperature stability, and flammability testing-going beyond basic package flammability to validate functional safety in telecom, medical, and industrial isolation barriers. The 1SMB7.5AT3 is one of few TVS diodes with full UL 497B listing across its entire voltage range.
How does the 1SMB7.5AT3 differ from the 1SMB7.5AT3G variant?
The 1SMB7.5AT3G is the Pb-free version of the 1SMB7.5AT3, with identical electrical specifications, thermal performance, and mechanical dimensions. Both share the same SMB (DO-214AA) package, 7.5 V VRWM, and 12.9 V clamping voltage. The "G" suffix denotes compliance with RoHS Directive 2011/65/EU and compatibility with lead-free reflow profiles (up to 260°C for 10 seconds). No derating or layout changes are needed when substituting 1SMB7.5AT3G for 1SMB7.5AT3.
Can the 1SMB7.5AT3 be used in bidirectional protection applications?
No, the 1SMB7.5AT3 is strictly unidirectional and must not be used for bidirectional surge suppression. Its cathode-anode polarity is fixed, and reverse conduction only occurs above VRWM. For AC lines or differential signals requiring symmetrical clamping, ON Semiconductor offers the 1SMB7.5CAT3 series (bidirectional variants). Using the 1SMB7.5AT3 in place of a bidirectional TVS would leave the positive half-cycle unprotected and risk catastrophic failure.
What is the maximum allowable ambient temperature for continuous operation of the 1SMB7.5AT3?
The 1SMB7.5AT3 has an operating temperature range of −65 °C to +150 °C, but its DC power dissipation is derated above +25 °C. At +75 °C ambient, the device supports only 3.0 W (vs. 0.55 W at +25 °C), with thermal resistance of 226 °C/W (junction-to-ambient) on standard FR-4. For sustained high-temperature environments, PCB copper area and airflow must be optimized-consult Figure 3 (Pulse Derating Curve) and Figure 4 (Thermal Resistance) in the official 1SMB5.0AT3 Series datasheet for precise derating guidance.
1SMB7.5AT3 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):
- 7.5V
- Voltage - Breakdown (Min):
- 8.33V
- Voltage - Clamping (Max) @ Ipp:
- 12.9V
- Current - Peak Pulse (10/1000µs):
- 46.5A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 1890pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB7.5AT3 FAQ
1.How can I place an order for 1SMB7.5AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB7.5AT3 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 1SMB7.5AT3 reliable?
The price and inventory of 1SMB7.5AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB7.5AT3 is usually 5 days.
3.What payment methods are accepted for 1SMB7.5AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB7.5AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB7.5AT3?
1SMB7.5AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB7.5AT3 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 1SMB7.5AT3?
For technical support, including 1SMB7.5AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB7.5AT3 requirements.
6.How does Aetrix verify that 1SMB7.5AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB7.5AT3 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 1SMB7.5AT3 meets industry standards.
7.What is the process for return or replacement of 1SMB7.5AT3?
All 1SMB7.5AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB7.5AT3, 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 1SMB7.5AT3 part is unused and in its original packaging.
Return procedure for 1SMB7.5AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB7.5AT3 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…
