My Inquiry
My Account
onsemi 1SMB33CAT3
- Part No.:
- 1SMB33CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB33CAT3.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,031
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMB33CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 33 V working peak reverse voltage (VRWM), 40.6 V clamping voltage at 11.3 A peak pulse current, and sub-1 ns response time. Used in power supplies, automotive ECUs, and industrial controllers to absorb ESD and lightning-induced surges.
For engineers reviewing the 1SMB33CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ circuit operating voltage, VC < device withstand rating, IPP capability under IEC 61000-4-5 waveforms, UL 497B certification for isolated loop protection, and SMB package thermal performance at 75°C lead temperature.
Technical Context
The 1SMB33CAT3 operates as a bidirectional Zener-based TVS, leveraging avalanche breakdown to clamp transients above VRWM. Its low zener impedance and fast turn-on (<1 ns) minimize voltage overshoot during surge events, while its 600 W peak power rating (10/1000 µs waveform) supports high-energy transient suppression without thermal runaway.
Designed for surface-mount use in the SMB (DO-214AA) package, it delivers 5.0 µA max reverse leakage at VRWM and meets Class 3 ESD immunity (>16 kV HBM). UL 497B recognition confirms compliance for isolated loop circuit protection in telecom and industrial interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 33 V - Maximum continuous reverse operating voltage before clamping begins; must exceed system DC bus or signal swing. |
| VC @ IPP | 53.3 V @ 11.3 A - Clamped voltage seen by protected circuit during full 600 W surge; defines minimum safe withstand margin. |
| IPP | 11.3 A - Peak pulse current supported at 10/1000 µs waveform; determines surge energy handling (≈33 J). |
| RJA | 226 °C/W - Thermal resistance from junction to ambient on FR-4 board; limits continuous power dissipation to 0.55 W at 25°C. |
| Response Time | <1 ns - Time from transient onset to clamping initiation; critical for protecting high-speed logic and analog inputs. |
| ESD Rating | >16 kV HBM - Robustness against human-body-model electrostatic discharge; eliminates need for external ESD staging. |
| UL Recognition | UL 497B QVGV2 - Certified for isolated loop protection; validates dielectric strength, endurance, and strike voltage performance. |
Pinout & Package
1SMB33CAT3 uses the SMB (DO-214AA) surface-mount package per Case 403A, with void-free thermosetting plastic body, corrosion-resistant finish, and modified L-bend leads for enhanced pad adhesion. Polarity band is omitted due to bidirectional symmetry.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode / Anode | Bidirectional terminal pair | Identical terminals; either end connects to line or ground - no polarity dependency in AC or differential signal paths. |
| Case / Body | Non-conductive enclosure | No electrical connection; mechanical mounting only; thermal path to PCB copper via soldered leads. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables symmetric protection of AC lines, RS-485 buses, and ungrounded sensor interfaces without polarity concerns. |
| 600 W peak power (1 ms) | Withstands IEC 61000-4-5 Level 4 surges (4 kV line-earth) on properly decoupled 24 V systems without failure. |
| UL 497B certification | Validates suitability for safety-critical telecom and industrial isolation barriers - not just flammability compliance. |
| <1 ns response time | Minimizes voltage overshoot before clamping engages, reducing risk of latch-up or gate oxide damage in downstream ICs. |
| Low leakage (<5 µA @ VRWM) | Prevents measurable standby current increase in battery-powered or high-impedance monitoring circuits. |
Applications
| Industrial Power Supplies | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Protection of 24 V DC input rails against load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed directly across input terminals upstream of DC-DC converters. Use Value: Limits transient excursions to ≤53.3 V, preventing damage to 36 V-rated input capacitors and controller ICs. |
Use Scenario: Safeguarding LIN bus transceivers and microcontroller I/O pins from ESD and inductive switching noise. IC Role / Device Role / Timing Role: Bidirectional shunt element on LIN data line, referenced to vehicle chassis ground. Use Value: Clamps ±15 kV contact ESD per ISO 10605 without signal distortion or latch-up in connected MCUs. |
| Medical Imaging Power Interfaces | Programmable Logic Controller I/O Cards |
|
Use Scenario: Shielding high-voltage X-ray generator control signals from coupling-induced spikes during tube firing. IC Role / Device Role / Timing Role: Transient suppressor on isolated 5 V/24 V control lines between FPGA and HV driver modules. Use Value: Maintains signal integrity under 1 kV fast-rising transients (tr < 10 ns) due to sub-1 ns response and low capacitance. |
Use Scenario: Protecting digital input channels from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Front-end clamp on 24 V sink-input terminals, mounted adjacent to connector footprint. Use Value: Absorbs 2 A–10 A surge currents per IEC 61000-4-4 (EFT) without degradation over 100,000+ events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33CA | Same VRWM (33 V), identical SMB package, but rated for 600 W with tighter VBR tolerance (±5% vs ±10% for 1SMB33CAT3). | Preferred where precise clamping threshold is required, e.g., in regulated 3.3 V or 5 V rail protection with narrow voltage margins. | Select SMBJ33CA when design requires guaranteed VBR consistency across production lots; 1SMB33CAT3 remains optimal for cost-sensitive, high-volume industrial use. |
| 1.5SMC33CA | Higher 1500 W peak power rating, same VRWM and VC, but larger SMC (DO-214AB) package (7.1 mm × 6.2 mm vs 4.6 mm × 3.9 mm). | Suitable for higher-energy environments (e.g., 48 V telecom rectifiers), but requires PCB layout revision due to footprint mismatch. | Choose 1.5SMC33CA only if surge threat exceeds 600 W; otherwise, 1SMB33CAT3 offers superior space efficiency and thermal performance per unit area. |
Compared with SMBJ33CA, 1SMB33CAT3 trades tighter VBR tolerance for lower unit cost and broader qualification history in automotive-grade production; versus 1.5SMC33CA, it delivers identical clamping performance in 45% less board area but with reduced single-pulse energy headroom.
Availability
1SMB33CAT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive control units, and medical equipment requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1SMB33CAT3 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 is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete devices for automotive, industrial, and cloud power applications.
The 1SMB33CAT3 belongs to the SMB-series transient voltage suppressors, engineered specifically for high-reliability, surface-mount overvoltage protection in harsh electromagnetic environments.
FAQ
What is the clamping voltage of the 1SMB33CAT3 under maximum surge conditions?
The 1SMB33CAT3 exhibits a maximum clamping voltage (VC) of 53.3 V when subjected to its rated peak pulse current of 11.3 A (10/1000 µs waveform). This value is measured per ON Semiconductor's test conditions and defines the upper voltage limit imposed on protected circuitry during worst-case transient events. Designers must ensure downstream components have sufficient voltage margin above this 53.3 V threshold to avoid stress or failure.
Is the 1SMB33CAT3 suitable for bidirectional signal line protection like RS-485?
Yes, the 1SMB33CAT3 is explicitly designed as a bidirectional TVS diode, making it appropriate for protecting balanced differential interfaces such as RS-485, CAN, or LVDS. Its symmetrical breakdown behavior ensures equal clamping on both positive and negative transients without polarity constraints. When placed across the A/B lines or referenced to ground, it maintains signal integrity while suppressing ESD and fast transients up to 11.3 A.
Does the 1SMB33CAT3 require heatsinking in typical applications?
No additional heatsinking is required for the 1SMB33CAT3 under normal operating conditions because its 600 W rating applies only to non-repetitive 1 ms pulses. For continuous operation, its DC power dissipation is limited to 0.55 W at 25°C ambient (derating to zero at 150°C). In most PCB layouts using standard 1 oz copper, thermal management relies on solder pad area and trace width-not external heatsinks-making it ideal for compact, high-density designs.
How does UL 497B recognition benefit designs using the 1SMB33CAT3?
UL 497B recognition confirms that the 1SMB33CAT3 has passed rigorous testing-including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge validation-for use in isolated loop protectors. This certification simplifies safety approvals for telecom, industrial control, and medical systems by eliminating the need for redundant external protection or custom qualification, directly supporting compliance with IEC 60950-1 and IEC 62368-1 requirements.
What is the maximum reverse leakage current of the 1SMB33CAT3 at its rated VRWM?
The 1SMB33CAT3 specifies a maximum reverse leakage current (IR) of 5.0 µA at its working peak reverse voltage of 33 V and ambient temperature of 25°C. This low leakage ensures minimal impact on high-impedance sensing circuits, battery-backed systems, or precision reference networks, preserving accuracy and extending operational life without introducing parasitic loading effects.
1SMB33CAT3 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):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 11.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 265pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB33CAT3 FAQ
1.How can I place an order for 1SMB33CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB33CAT3 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 1SMB33CAT3 reliable?
The price and inventory of 1SMB33CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB33CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMB33CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB33CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB33CAT3?
1SMB33CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB33CAT3 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 1SMB33CAT3?
For technical support, including 1SMB33CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB33CAT3 requirements.
6.How does Aetrix verify that 1SMB33CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB33CAT3 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 1SMB33CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMB33CAT3?
All 1SMB33CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB33CAT3, 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 1SMB33CAT3 part is unused and in its original packaging.
Return procedure for 1SMB33CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB33CAT3 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…
