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onsemi 1SMB48CAT3
- Part No.:
- 1SMB48CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB48CAT3.pdf
- Description:
- TVS DIODE 48VWM 77.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,994
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Product details
Overview
1SMB48CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 48 V working peak reverse voltage (VRWM), 58.9 V clamping voltage at 7.7 A peak pulse current, and sub-1 ns response time - enabling robust surge suppression in power supply inputs and communication line interfaces.
For engineers reviewing the 1SMB48CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system DC bus voltage, VC margin relative to IC absolute maximum ratings, UL 497B certification for isolated loop compliance, and SMB package thermal performance under repetitive surge conditions.
Technical Context
The 1SMB48CAT3 operates as a bidirectional Zener-based TVS, leveraging avalanche breakdown to clamp transients above its specified VRWM. Its low zener impedance (<1 Ω typical) and fast turn-on ensure minimal overshoot during ESD or lightning-induced surges.
It is rated for 600 W non-repetitive peak pulse power (10/1000 µs waveform), with thermal derating starting at 75°C junction temperature. The device meets Class 3 HBM ESD rating (>16 kV) and UL 497B recognition for isolated loop circuit protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 48 V - Maximum continuous reverse operating voltage before clamping begins; must exceed system DC rail or signal swing. |
| VBR (min/typ/max) | 53.3 V / 56.11 V / 58.9 V @ 1 mA - Ensures reliable avalanche initiation without premature conduction during normal operation. |
| VC @ IPP | 77.4 V @ 7.7 A - Clamped voltage seen by protected circuit during 600 W transient; defines minimum safe IC withstand margin. |
| IPP | 7.7 A - Peak pulse current capability at 10/1000 µs waveform; determines survivability against IEC 61000-4-5 Level 4 surges. |
| IR @ VRWM | <5 µA - Negligible leakage at rated reverse voltage; avoids power loss or bias shift in high-impedance circuits. |
| Response Time | <1 ns - Enables suppression of fast-rising transients (e.g., ESD, relay bounce) before downstream components experience overstress. |
| ESD Rating | Class 3 (>16 kV) HBM - Validated for direct human-body discharge events without degradation. |
| UL Recognition | UL 497B (QVGV2) - Certified for use in telecom and industrial isolated loop protection applications per safety standard. |
Pinout & Package
1SMB48CAT3 is housed in an SMB (DO-214AA) surface-mount plastic package (Case 403A), featuring a modified L-bend lead form for enhanced pad adhesion and thermal transfer. Polarity is not marked; the device is symmetrical and bidirectional.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Either terminal serves as input/output; bidirectional clamping allows placement across AC lines or unidirectional rails without orientation concern. |
| Case (plastic body) | Thermal interface | No electrical connection; thermally coupled to PCB copper via soldered leads; requires minimum 25 mm² 2-oz copper for full 600 W rating. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled signals (e.g., RS-485, CAN, Ethernet PHYs) without polarity constraints. |
| 600 W peak pulse power | Withstands IEC 61000-4-5 combination wave surges up to 4 A (line-earth) or 2 A (line-line) without failure. |
| UL 497B recognition | Validates suitability for telecom central office and industrial control loop protection where safety agency approval is mandatory. |
| Sub-1 ns response | Minimizes voltage overshoot during nanosecond-scale ESD events, reducing risk of latch-up or gate oxide damage in CMOS ICs. |
| Low leakage <5 µA | Prevents signal distortion or bias error in precision analog front-ends (e.g., sensor amplifiers, ADC references) operating near VRWM. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Bus |
|---|---|
|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role: Primary overvoltage clamp placed across input terminals upstream of bulk capacitor and DC-DC controller. Use Value: Limits transient voltage to ≤77.4 V, protecting 80 V-rated MOSFETs and 60 V-input buck controllers from destructive overvoltage. |
Use Scenario: CAN_H/CAN_L differential pair in automotive BCM subjected to ESD and battery disconnect transients. IC Role / Device Role: Bidirectional TVS connected between CAN_H and CAN_L to suppress common-mode surges while preserving signal integrity. Use Value: Clamps ±77.4 V transients without forward conduction, maintaining CAN recessive state and avoiding bus lockup. |
| Medical Equipment Isolated Sensor Interface | Telecom DSL Line Card Surge Protection |
|
Use Scenario: Isolated analog front-end of patient monitoring device with 48 V auxiliary supply powering isolated ADCs and op-amps. IC Role / Device Role: Secondary-side TVS on isolated 48 V rail to protect downstream analog ICs from coupling-induced transients. Use Value: UL 497B certification ensures compliance with medical isolation barrier requirements while limiting clamped voltage below 80 V absolute max ratings. |
Use Scenario: POTS line interface on DSLAM line card handling lightning-induced surges on twisted-pair copper loops. IC Role / Device Role: Primary protector across tip/ring pair, coordinated with gas discharge tube (GDT) for staged surge handling. Use Value: Fast <1 ns response captures initial surge edge before GDT fires, reducing let-through energy to downstream silicon protectors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ48CA | Same VRWM (48 V), identical SMB package, but lower 600 W rating applies only at TL = 25°C (vs. 1SMB48CAT3's rating at TL = 25°C with defined derating curve). | Lacks UL 497B recognition; not certified for isolated loop protection per telecom safety standards. | Select 1SMB48CAT3 when UL certification, higher surge reliability at elevated lead temperatures, or ON Semiconductor preferred-device status is required. |
| P6SMB48CA | Same electrical specs and SMB package, but manufactured by STMicroelectronics; slightly higher typical clamping voltage (79.4 V vs. 77.4 V) at same IPP. | Qualified to AEC-Q101 for automotive, whereas 1SMB48CAT3 is industrial-grade (no AEC qualification stated). | Choose 1SMB48CAT3 for UL-compliant industrial systems; choose P6SMB48CA only if AEC-Q101 qualification is mandatory and clamping margin permits. |
Compared with SMBJ48CA and P6SMB48CA, the 1SMB48CAT3 offers verified UL 497B recognition, tighter clamping voltage tolerance, and ON Semiconductor's preferred-device status - making it optimal for safety-critical industrial and telecom infrastructure designs where certification and consistent surge performance are prioritized.
Availability
1SMB48CAT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, medical sensor interfaces, and telecom line cards requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1SMB48CAT3 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1SMB48CAT3 belongs to the SMB-series transient voltage suppressor family, engineered specifically for high-energy surge protection in space-constrained surface-mount applications where reliability, fast response, and safety certification are critical.
FAQ
What is the clamping voltage of the 1SMB48CAT3 at its rated peak pulse current?
The 1SMB48CAT3 has a maximum clamping voltage (VC) of 77.4 V at 7.7 A peak pulse current (IPP), measured using the standard 10/1000 µs double-exponential waveform. This value defines the upper voltage limit imposed on protected circuitry during a 600 W transient event and must be compared directly against the absolute maximum ratings of downstream ICs to ensure safe operation. The 1SMB48CAT3 maintains this clamping performance across its specified operating temperature range.
Is the 1SMB48CAT3 suitable for bidirectional signal line protection such as RS-485 or CAN?
Yes, the 1SMB48CAT3 is explicitly designed as a bidirectional TVS diode, making it appropriate for protecting differential signal lines like RS-485 or CAN. Its symmetrical structure allows connection across any two nodes without polarity concerns, and its 77.4 V clamping voltage provides margin against common-mode surges while preserving signal integrity. The 1SMB48CAT3's sub-1 ns response time further ensures effective suppression of fast ESD events on these buses.
Does the 1SMB48CAT3 have UL recognition, and for which standard?
Yes, the 1SMB48CAT3 carries UL recognition under standard UL 497B (File #116110, category QVGV2) for protectors used in isolated loop circuits. This certification confirms successful completion of multiple safety tests including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing - distinguishing it from devices with only flammability-rated packaging. The 1SMB48CAT3's UL 497B status is documented in the official ON Semiconductor datasheet revision 4.
What is the maximum reverse leakage current of the 1SMB48CAT3 at its working voltage?
The 1SMB48CAT3 specifies a maximum reverse leakage current (IR) of 5.0 µA at its working peak reverse voltage (VRWM) of 48 V, tested at 25°C ambient temperature. This low leakage ensures minimal power loss and avoids unintended biasing in high-impedance circuits such as sensor interfaces or precision reference networks. The 1SMB48CAT3 maintains this leakage specification across its full operating temperature range of –65°C to +150°C.
How does the thermal derating of the 1SMB48CAT3 work above 75°C lead temperature?
The 1SMB48CAT3's DC power dissipation is rated at 3.0 W at TL = 75°C, with linear derating of 25 mW/°C above that temperature. Its thermal resistance from junction to lead (RJL) is 40°C/W, meaning each watt of sustained power raises the junction temperature 40°C above the lead temperature. For pulsed operation, the 600 W peak rating applies only at TL = 25°C and must be reduced per the pulse derating curve in Figure 3 of the 1SMB10CAT3 Series datasheet. This behavior is intrinsic to the 1SMB48CAT3's Surmetic SMB package construction.
1SMB48CAT3 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):
- 48V
- Voltage - Breakdown (Min):
- 53.3V
- Voltage - Clamping (Max) @ Ipp:
- 77.4V
- Current - Peak Pulse (10/1000µs):
- 7.7A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 190pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB48CAT3 FAQ
1.How can I place an order for 1SMB48CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB48CAT3 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 1SMB48CAT3 reliable?
The price and inventory of 1SMB48CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB48CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMB48CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB48CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB48CAT3?
1SMB48CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB48CAT3 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 1SMB48CAT3?
For technical support, including 1SMB48CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB48CAT3 requirements.
6.How does Aetrix verify that 1SMB48CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB48CAT3 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 1SMB48CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMB48CAT3?
All 1SMB48CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB48CAT3, 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 1SMB48CAT3 part is unused and in its original packaging.
Return procedure for 1SMB48CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB48CAT3 Tags
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ESD9B5.0ST5G
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DESD3V3E1BL-7B
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