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onsemi 1SMA30CAT3
- Part No.:
- 1SMA30CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA30CAT3.pdf
- Description:
- TVS DIODE 30VWM 48.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,411
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Product details
Overview
1SMA30CAT3 from ON Semiconductor is a bidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed for clamping high-energy transients in DC power rails and signal lines. It features a 30 V working peak reverse voltage (VRWM), 48.4 V clamping voltage at 8.3 A peak pulse current, and <1 ns response time. It is used in automotive power supply protection and industrial control I/O interfaces.
For engineers reviewing the 1SMA30CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, clamping voltage margin relative to protected IC VMAX, surge current rating under 10/1000 µs waveform, and junction capacitance (210 pF at 0 V) for high-speed signal line compatibility.
Technical Context
This device operates as a bidirectional avalanche diode, conducting symmetrically in both polarities once reverse voltage exceeds breakdown (33.3–36.81 V at 1 mA). Its low zener impedance and fast <1 ns response enable effective suppression of ESD (Class 3 >16 kV HBM) and lightning-induced surges.
The SMA package (Case 403D) supports top-slide or bottom-mount PCB placement with flat handling surface and Pb-free construction. Thermal resistance from junction-to-lead is 50 °C/W, enabling 1.5 W DC dissipation at 75 °C ambient with appropriate copper pad layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 30 V - maximum continuous reverse voltage before clamping begins; must exceed circuit's peak operating voltage |
| VBR @ IT | 33.3–36.81 V @ 1 mA - precise breakdown range defining turn-on threshold under test conditions |
| VC @ IPP | 48.4 V @ 8.3 A - clamping voltage during 10/1000 µs surge; determines maximum stress on downstream components |
| PPK | 400 W @ 1 ms - peak surge power handling capability per non-repetitive pulse |
| CJ | 210 pF @ 0 V - junction capacitance affecting signal integrity on data lines; limits use in >10 Mbps interfaces |
| Response Time | <1 ns - time from overvoltage onset to conduction; ensures protection before sensitive ICs are damaged |
| ESD Rating | Class 3 (>16 kV HBM) - qualifies for robust electrostatic discharge immunity in end-user environments |
Pinout & Package
Package: SMA (Case 403D), surface-mount plastic package with cathode polarity notch (non-polarity-indicating); dimensions: 4.06–4.57 mm length × 2.29–2.92 mm width × 1.97–2.20 mm height.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias; reverse-bias conduction path for negative transients | Connected to lower-potential side of protected node (e.g., GND or signal return) |
| Cathode | Current exit terminal in forward bias; reverse-bias conduction path for positive transients | Connected to higher-potential side (e.g., VCC or signal line); marked by notch on package body |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC-coupled or floating signal lines without polarity constraints (e.g., RS-485, CAN bus) |
| Low-profile SMA package | Enables high-density PCB layouts and automated optical inspection (AOI) due to flat top surface |
| 400 W peak power rating | Withstands IEC 61000-4-5 Level 4 surges (4 kV line-earth) when properly mounted on FR-4 with thermal relief |
| AEC-Q101 qualified (SZ variant) | Validated for automotive under-hood applications including engine control modules and body electronics |
| Pb-free and RoHS compliant | Meets global environmental regulations; compatible with lead-free reflow profiles up to 260°C for 10 seconds |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Suppressing load dump transients (up to 60 V, 100 ms) on 12 V battery-fed ECUs. IC Role / Device Role / Timing Role: Bidirectional TVS placed between VBAT and GND to clamp overvoltage before it reaches LDOs and microcontrollers. Use Value: Limits peak voltage to 48.4 V, preventing damage to 45 V-rated input stages while surviving 400 W surges. | Use Scenario: Guarding 24 V digital input channels against field-wiring induced surges in factory automation. IC Role / Device Role / Timing Role: Standoff device across input terminals to shunt energy from inductive switching noise and accidental 48 V miswiring. Use Value: Clamps within 1 ns to protect optocoupler inputs rated ≤50 V, with 210 pF capacitance avoiding signal edge degradation at 100 kHz scan rates. |
| Medical Equipment ESD Shielding | Telecom Line Interface Protection |
Use Scenario: Protecting front-panel USB and Ethernet ports on diagnostic imaging systems from hospital-grade ESD events. IC Role / Device Role / Timing Role: Secondary-level TVS after common-mode chokes, absorbing residual ±15 kV contact discharge per IEC 61000-4-2. Use Value: Class 3 HBM rating (>16 kV) ensures reliability across repeated clinical handling; bidirectional symmetry avoids polarity errors during assembly. | Use Scenario: Safeguarding RS-232/RS-485 transceivers connected to long external wiring in building management systems. IC Role / Device Role / Timing Role: Differential-line TVS pair (one per line) referenced to local ground, clamping cross-talk and lightning-induced common-mode spikes. Use Value: 30 V VRWM matches typical 25 V RS-485 common-mode range; 48.4 V clamping stays below transceiver absolute max ratings (±60 V). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMA30CAT3G | AEC-Q101 qualified; identical electrical specs but with automotive-specific traceability and PPAP documentation | Required for Tier 1 automotive designs; not necessary for industrial or medical consumer-grade use | Select SZ1SMA30CAT3G only when automotive qualification and change control are mandated |
| 1SMA30AT3G | Unidirectional version; same VRWM, VBR, and PPK, but conducts only in reverse direction | Suitable only for DC-biased lines where polarity is fixed (e.g., +5 V supply rail), not AC or floating signals | Choose 1SMA30AT3G only if circuit topology guarantees unidirectional overvoltage risk and space allows separate GND-referenced placement |
Compared with 1SMA30CAT3, SZ1SMA30CAT3G adds automotive compliance overhead without electrical benefit, while 1SMA30AT3G sacrifices bidirectional protection for slightly lower capacitance (195 pF) - trade-offs that require explicit system-level validation before substitution.
Availability
1SMA30CAT3 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial PLC digital I/O protection, and medical equipment ESD shielding requiring stable component supply and full traceability.
Supply support for 1SMA30CAT3 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 1SMAxxCAT3G series belongs to ON Semiconductor's SURMETIC® TVS portfolio, engineered specifically for high-reliability transient suppression in harsh environments where surge immunity, thermal stability, and long-term parametric consistency are critical.
FAQ
What is the clamping voltage of the 1SMA30CAT3 under a standard 10/1000 µs surge?
The 1SMA30CAT3 clamps to 48.4 V when subjected to its rated peak pulse current of 8.3 A under the 10/1000 µs waveform defined by R.E.A. This value is measured at TA = 25°C and represents the maximum voltage seen by downstream circuitry during surge events. The 1SMA30CAT3 maintains this clamping performance across its specified operating temperature range, making it suitable for under-hood automotive and industrial control applications where thermal derating must be considered.
Is the 1SMA30CAT3 suitable for protecting high-speed data lines like USB 2.0?
The 1SMA30CAT3 has a junction capacitance of 210 pF at 0 V bias, which exceeds the typical ≤5 pF requirement for full-speed USB 2.0 (480 Mbps) signal integrity. While it can protect low-speed USB 1.1 or RS-232 lines, using the 1SMA30CAT3 on USB 2.0 differential pairs would cause excessive signal attenuation and jitter. For such interfaces, a low-capacitance TVS like the NUP4201MR6T1G (12 pF) is recommended instead of the 1SMA30CAT3.
Does the 1SMA30CAT3 have automotive qualification?
The base 1SMA30CAT3 is not AEC-Q101 qualified; however, its automotive-grade variant SZ1SMA30CAT3G is fully AEC-Q101 qualified and PPAP capable. Both share identical electrical specifications and SMA package dimensions, but only SZ1SMA30CAT3G meets the extended temperature cycling, humidity testing, and traceability requirements for automotive electronics. If your design targets automotive production, specify SZ1SMA30CAT3G - the 1SMA30CAT3 remains appropriate for industrial and medical applications.
How does the 1SMA30CAT3 compare to unidirectional TVS diodes like 1SMA30AT3G?
The 1SMA30CAT3 is bidirectional, meaning it clamps overvoltage in both polarities - essential for AC-coupled or floating nodes like RS-485 or audio lines. In contrast, 1SMA30AT3G conducts only in reverse bias and requires correct orientation relative to DC bias. Their VRWM, VBR, and PPK match, but the 1SMA30CAT3's 210 pF capacitance is slightly higher than the 1SMA30AT3G's 195 pF. System-level polarity and signal type determine whether the 1SMA30CAT3 or 1SMA30AT3G is appropriate.
What PCB layout practices maximize surge handling for the 1SMA30CAT3?
To maximize surge performance, route the 1SMA30CAT3 with minimal trace length (<2 mm) directly across the protected node and ground plane. Use a minimum 1 in² copper pad per terminal (per ON Semiconductor's Case 403D footprint recommendation) to reduce thermal resistance and sustain 400 W pulses. Avoid vias in the current path and ensure solder mask openings fully expose thermal pads. These practices prevent localized overheating and ensure the 1SMA30CAT3 delivers its rated 400 W peak power without bond wire failure or package cracking.
1SMA30CAT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 30V
- Voltage - Breakdown (Min):
- 33.3V
- Voltage - Clamping (Max) @ Ipp:
- 48.4V
- Current - Peak Pulse (10/1000µs):
- 8.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 210pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA30CAT3 FAQ
1.How can I place an order for 1SMA30CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA30CAT3 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 1SMA30CAT3 reliable?
The price and inventory of 1SMA30CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA30CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMA30CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA30CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA30CAT3?
1SMA30CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA30CAT3 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 1SMA30CAT3?
For technical support, including 1SMA30CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA30CAT3 requirements.
6.How does Aetrix verify that 1SMA30CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA30CAT3 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 1SMA30CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMA30CAT3?
All 1SMA30CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA30CAT3, 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 1SMA30CAT3 part is unused and in its original packaging.
Return procedure for 1SMA30CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA30CAT3 Tags
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