My Inquiry
My Account
onsemi 1SMB75CAT3
- Part No.:
- 1SMB75CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB75CAT3.pdf
- Description:
- TVS DIODE 75VWM 121VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:3,479
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMB75CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 75 V working peak reverse voltage (VRWM), 92.07 V maximum clamping voltage at 4.9 A peak pulse current, and sub-1 ns response time. Used in power supplies, industrial controls, and automotive ECUs to absorb ESD and lightning-induced surges.
For engineers reviewing the 1SMB75CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system DC bus voltage, VC margin below IC absolute maximum ratings, UL 497B certification for isolated loop protection, and SMB package thermal performance under repetitive surge conditions.
Technical Context
The 1SMB75CAT3 operates as a bidirectional Zener-based TVS, conducting symmetrically during positive and negative transients above its breakdown threshold. Its low zener impedance and fast turn-on (<1 ns) enable effective clamping of fast-rising ESD events (IEC 61000-4-2) and surge waveforms (10/1000 µs).
It is rated for 600 W non-repetitive peak pulse power at 1 ms, with thermal derating to 0.55 W at TA = 25°C and junction-to-ambient thermal resistance of 226 °C/W on FR-4 board. UL 497B recognition confirms compliance for isolated loop circuit protection applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 75 V - Minimum continuous operating voltage before clamping begins; must exceed system DC rail or AC peak voltage. |
| VBR (min/typ/max) | 81.90 / 91.65 / 95.83 V @ 1 mA - Ensures predictable turn-on with tight tolerance for consistent protection threshold. |
| VC @ IPP | 121 V @ 4.9 A - Maximum clamped voltage seen by protected circuit during 10/1000 µs surge; defines safe margin vs. load IC rating. |
| IPP | 4.9 A - Peak pulse current capability at 1 ms pulse width; determines surge energy absorption (600 W). |
| IR @ VRWM | < 5 µA - Negligible leakage at operating voltage; avoids power loss or false triggering in high-impedance circuits. |
| Response Time | < 1 ns - Enables suppression of nanosecond-scale ESD transients before downstream components experience overstress. |
| ESD Rating | Class 3 (>16 kV HBM) - Meets stringent electrostatic discharge immunity requirements for end-equipment certification. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, void-free thermosetting plastic case (Case 403A). Dimensions: 4.06–4.57 mm × 3.30–3.81 mm × 1.90–2.41 mm (L×W×H); lead finish solderable per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Negative terminal in unidirectional mode; symmetrical conduction path in bidirectional operation | Connected to ground or low-side reference; enables clamping of both polarities without polarity marking. |
| Cathode | Positive terminal in unidirectional mode; symmetrical conduction path in bidirectional operation | Connected to protected line (e.g., VBUS, signal line); forms low-impedance shunt path during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC lines and floating signals without polarity constraints; eliminates need for dual-device placement. |
| UL 497B recognition | Validated for isolated loop circuit protection-required for telecom, industrial I/O, and safety-critical interfaces. |
| 600 W peak pulse power | Handles high-energy transients (e.g., ISO 7637-2 Pulse 5a) without degradation when mounted per recommended footprint. |
| Low clamping ratio (VC/VBR ≈ 1.32) | Minimizes voltage overshoot during surge events-critical for protecting 3.3 V/5 V logic and analog front-ends. |
| Surmetic® package reliability | ON Semiconductor's proprietary molding ensures moisture resistance, thermal cycling stability, and long-term solder joint integrity. |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and inductive switching noise. IC Role / Device Role / Timing Role: Bidirectional TVS placed across input terminals to clamp transients before they reach upstream rectifier and downstream DC-DC converter. Use Value: With 75 V VRWM and 121 V VC, it protects 40 V-rated input capacitors and MOSFETs while surviving repeated 100 V/500 ms load dump pulses. | Use Scenario: LIN bus line in body control unit subjected to ESD events and battery reversal during service. IC Role / Device Role / Timing Role: Parallel-connected TVS on LIN data line to limit voltage excursion during ±8 kV contact discharge (IEC 61000-4-2). Use Value: Sub-1 ns response ensures clamping occurs before LIN transceiver input stages are damaged; bidirectional symmetry supports bidirectional data flow. |
| Medical Equipment Isolated Interface | Telecom Line Card Surge Protection |
Use Scenario: Isolated RS-485 port on patient monitor connected to external peripherals via unshielded cabling. IC Role / Device Role / Timing Role: TVS on differential pair (A/B lines) referenced to isolated ground, certified per UL 497B for secondary circuit protection. Use Value: UL 497B listing validates suitability for medical isolation barriers; 5 µA leakage prevents signal distortion in high-impedance bias networks. | Use Scenario: TIP/RING lines of VoIP gateway exposed to lightning-induced surges on POTS wiring. IC Role / Device Role / Timing Role: Primary-level TVS on line interface transformer secondary side, coordinated with gas discharge tube (GDT) upstream. Use Value: 600 W rating absorbs residual energy after GDT fires; 121 V clamping keeps protected PHY IC within 130 V absolute max rating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ75CA | Same VRWM (75 V), identical SMB package, but lower 600 W rating applies only at TL = 25°C (not TA); higher RJA (250 °C/W vs. 226 °C/W). | Less margin in ambient-temperature-constrained layouts; requires tighter thermal management on PCB. | Select 1SMB75CAT3 when UL 497B certification or verified 226 °C/W RJA on FR-4 is required. |
| P6SMB75CA | Same electrical specs and SMB package, but obsolete per ON Semi lifecycle notice; no new production after Q3 2022. | No long-term supply assurance; not recommended for new designs or volume production. | 1SMB75CAT3 is the active, preferred replacement with full manufacturing support and tape-and-reel availability. |
Compared with SMBJ75CA and P6SMB75CA, the 1SMB75CAT3 offers superior thermal performance on standard FR-4, mandatory UL 497B listing for isolated systems, and guaranteed long-term availability as an ON Semiconductor Preferred device.
Availability
1SMB75CAT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive control units, medical isolated interfaces, and telecom line cards requiring stable component supply across multi-year production cycles.
Supply support for 1SMB75CAT3 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 part of onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMB75CAT3 belongs to the SMB series of transient voltage suppressors-designed specifically for robust, surface-mount overvoltage protection in harsh environments where reliability, UL certification, and high surge capacity are critical.
FAQ
What is the clamping voltage of the 1SMB75CAT3 at its rated peak pulse current?
The 1SMB75CAT3 has a maximum clamping voltage (VC) of 121 V at its peak pulse current (IPP) of 4.9 A, measured under the standard 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuitry during surge events and must be compared against the absolute maximum ratings of downstream components to ensure safe operation. The 1SMB75CAT3 maintains this clamping performance across its specified temperature range and mounting conditions.
Is the 1SMB75CAT3 certified for use in safety-isolated circuits?
Yes, the 1SMB75CAT3 carries UL 497B recognition (File #116110, QVGV2 category) for isolated loop circuit protection. This certification verifies compliance with rigorous tests including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance-making it suitable for medical, telecom, and industrial applications requiring reinforced isolation barriers. The 1SMB75CAT3 is explicitly listed in ON Semiconductor's UL-certified devices table.
What is the thermal resistance of the 1SMB75CAT3 when mounted on a standard FR-4 PCB?
When mounted on an FR-4 board using ON Semiconductor's minimum recommended footprint (Case 403A outline), the 1SMB75CAT3 exhibits a junction-to-ambient thermal resistance (RJA) of 226 °C/W. This value assumes standard JEDEC test conditions and directly impacts allowable power dissipation at elevated ambient temperatures. Derating curves in the datasheet confirm that at TA = 75°C, the device supports 0.55 W continuous power dissipation-critical for thermal design validation of the 1SMB75CAT3.
Does the 1SMB75CAT3 have polarity markings on its package?
No, the 1SMB75CAT3 does not feature a polarity band or marking on its SMB package, as confirmed in the mechanical characteristics section of the datasheet. This reflects its bidirectional construction: both terminals behave identically under positive or negative overvoltage conditions. Layouts must treat the device as symmetric, with either terminal connectable to line or ground-eliminating orientation errors during automated assembly of the 1SMB75CAT3.
How does the 1SMB75CAT3 compare to older P6SMB75CA in terms of supply chain status?
The P6SMB75CA has been discontinued by ON Semiconductor, with last-time-buy announcements issued and no new production after Q3 2022. In contrast, the 1SMB75CAT3 is designated a Preferred Device in the ON Semiconductor portfolio, with active manufacturing, full tape-and-reel packaging (2500/reel), and documented long-term availability. For new designs and production ramp, the 1SMB75CAT3 is the only supported, lifecycle-guaranteed option replacing P6SMB75CA.
1SMB75CAT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 75V
- Voltage - Breakdown (Min):
- 83.3V
- Voltage - Clamping (Max) @ Ipp:
- 121V
- Current - Peak Pulse (10/1000µs):
- 4.9A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 125pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB75CAT3 FAQ
1.How can I place an order for 1SMB75CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB75CAT3 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 1SMB75CAT3 reliable?
The price and inventory of 1SMB75CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB75CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMB75CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB75CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB75CAT3?
1SMB75CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB75CAT3 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 1SMB75CAT3?
For technical support, including 1SMB75CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB75CAT3 requirements.
6.How does Aetrix verify that 1SMB75CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB75CAT3 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 1SMB75CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMB75CAT3?
All 1SMB75CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB75CAT3, 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 1SMB75CAT3 part is unused and in its original packaging.
Return procedure for 1SMB75CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB75CAT3 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…
