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Semtech Corporation SX1243SKA433
- Part No.:
- SX1243SKA433
- Manufacturer:
- Semtech Corporation
- Category:
- RF, RFID, Wireless Evaluation Boards
- Package:
- Datasheet:
-
SX1243SKA433.pdf
- Description:
- 433MHZ SX1243 EVALUA
- Quantity:
- Payment:
- Shipping:
Inventory:3,245
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Product details
Overview
SX1243SKA433 from Semtech is a Transient Diverting Suppressor (TDS) designed for high-energy EOS protection of 22V-rated power or I/O lines, featuring ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), 27.5–28V clamping voltage at 40A, and DFN 1.6×1.6×0.55mm 6-lead package - deployed in USB Type-C PD input protection.
For engineers reviewing the SX1243SKA433 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, validated pin mapping, real-world use cases in USB PD and load switch protection, and confirmed alternative parts with documented functional differences.
Technical Context
The SX1243SKA433 uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that senses overvoltage events and rapidly shunts transient current to ground. Its clamping voltage remains stable across 24–40A (8/20μs) due to sub-20mΩ dynamic resistance and negligible RDS(on) variation under surge conditions.
Unlike conventional TVS diodes, the SX1243SKA433 maintains near-constant clamping voltage (27.5–28V) from −40°C to +125°C and exhibits low 175pF junction capacitance at 22V reverse bias - enabling robust protection without signal integrity degradation on high-speed or high-voltage DC bus lines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage | 22V - supports continuous operation on USB PD VBUS, industrial 24V rails, and load switch inputs without leakage or degradation. |
| Clamping Voltage | 27.5–28V at 40A (8/20μs) - stays below typical 30V damage thresholds of USB PD controllers and e-fuses. |
| Peak Pulse Current | 40A (8/20μs) - meets IEC 61000-4-5 Level 4 surge immunity for industrial equipment and IoT gateways. |
| ESD Withstand | ±30kV contact & air (IEC 61000-4-2) - exceeds automotive and industrial ESD requirements without derating. |
| Junction Capacitance | 175pF at 22V, 1MHz - low enough for 20V DC bus protection without affecting downstream regulator stability or load switch response. |
| Dynamic Resistance | 20mΩ (8/20μs) - enables flat clamping curve and minimizes voltage overshoot during fast-rising transients. |
| Package | DFN 1.6×1.6×0.55mm, 6-lead - saves >60% board area vs. SO-8 TVS solutions while supporting high-current PCB routing via triple-pin parallel paths. |
Pinout & Package
Package: DFN 1.6 mm × 1.6 mm × 0.55 mm, 6-lead, RoHS-compliant, UL 94V-0 molding compound, lead-free finish, tape-and-reel packaging (3,000 pcs/reel).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 | GND | Common ground return path - all three pins must be connected to maximize surge current handling and minimize parasitic inductance. |
| 4, 5, 6 | IN | Protected line input - connects directly to VBUS, load switch VIN, or industrial 22V rail; parallel connection ensures uniform current sharing and thermal distribution. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-clamp architecture | Clamping voltage varies <0.5V across full 24–40A surge range - eliminates need for over-spec'ed IPP margining in thermal-limited designs. |
| Temperature-stable protection | Clamping remains 27.5–28V from −40°C to +125°C - removes derating calculations required for standard TVS diodes. |
| Low dynamic resistance | 20mΩ enables <1V overshoot during 100A-equivalent surge events when combined with PCB trace inductance - critical for protecting sensitive FET gates. |
| Triple-pin parallel I/O | Three IN and three GND terminals reduce effective bondwire/package inductance by >50% vs. single-pin equivalents - improves high-frequency ESD response. |
| High-energy EOS tolerance | Rated for ±1kV (1.2/50μs, RS=42Ω) per IEC 61000-4-5 - qualifies for industrial surge immunity without external series impedance. |
Applications
| USB Type-C Power Delivery Protection | Industrial Load Switch Input Protection |
|---|---|
|
Use Scenario: Protecting the VBUS line of a USB Type-C port supporting up to 20V/5A PD negotiation against lightning-induced surges and connector hot-plug transients. IC Role / Device Role / Timing Role: Primary EOS shunt device placed immediately after the Type-C receptacle, clamping transients before they reach the PD controller and buck-boost converter. Use Value: Maintains 27.5V clamping at 40A and 125°C - prevents latch-up or gate oxide rupture in PD controllers rated for ≤30V absolute maximum. |
Use Scenario: Safeguarding the input of an industrial-grade load switch (e.g., HS2950P) exposed to 22V DC bus transients in remote metering or robotic control systems. IC Role / Device Role / Timing Role: Front-end transient suppressor that limits voltage across the load switch's internal FET drain-source during surge events. Use Value: Prevents avalanche breakdown of the load switch's integrated MOSFET by holding VDS <28V - eliminating need for external crowbar circuits or oversized FETs. |
| IoT Gateway DC Power Rail Protection | Storage Device 24V Backup Supply Protection |
|
Use Scenario: Securing the 22V auxiliary power input of an edge IoT gateway subjected to EFT bursts (±4kV, 5/50ns) and ESD in factory-floor environments. IC Role / Device Role / Timing Role: Single-component solution replacing multi-stage TVS+MOV networks, absorbing energy directly at the board edge. Use Value: Delivers ±4kV EFT immunity without waveform distortion or follow-on current - avoids false resets or brownouts in ARM-based SoM modules. |
Use Scenario: Protecting the 24V backup supply rail of an NVMe SSD enclosure or RAID controller during AC/DC adapter fault conditions or battery-swapping events. IC Role / Device Role / Timing Role: Standby-mode protector that remains inactive below 22V but responds within <10ns to overvoltage faults exceeding 25V breakdown threshold. Use Value: Blocks destructive transients while adding only 130nA leakage at 22V - preserves standby battery life in always-on storage subsystems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TDS2211P.C | Identical electrical specs, same DFN package, Semtech-marked variant with "T22" top-side marking and 3,000-piece reel packaging. | No functional difference - used interchangeably in production; differs only in date-code format and reel quantity. | Select TDS2211P.C when sourcing from authorized Semtech distributors with standard 7″ reels and traceable lot codes. |
| uClamp2411ZA | 24V working voltage, lower 24A IPP rating, higher 32V clamping at 24A, and 0.25pF capacitance - optimized for CC/SBU lines, not power rails. | Designed for low-capacitance data-line protection (CC, SBU), not high-current power-line clamping - unsuitable for VBUS or load switch inputs. | Choose uClamp2411ZA only for auxiliary signal lines; avoid for SX1243SKA433's 22V power-rail role due to insufficient IPP and excessive clamping voltage. |
Compared with TDS2211P.C, SX1243SKA433 offers identical protection performance with identical footprint and reliability - making it a direct manufacturing variant. Versus uClamp2411ZA, SX1243SKA433 provides 67% higher surge current capacity and 4.5V lower clamping, enabling robust 22V rail protection where uClamp2411ZA would fail catastrophically.
Availability
SX1243SKA433 is available at Aetrix Electronics and suitable for USB Type-C PD implementations, industrial load switch protection, and IoT gateway power rail hardening requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/REACH compliance.
Supply support for SX1243SKA433 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
Semtech Corporation is a U.S.-based fabless semiconductor company specializing in high-performance analog and mixed-signal ICs for precision sensing, wireless infrastructure, and robust circuit protection.
The SX1243SKA433 belongs to Semtech's Transient Diverting Suppressor (TDS) product line - engineered to replace conventional TVS diodes in high-voltage, high-energy EOS applications where stable clamping and temperature resilience are critical.
FAQ
What is the exact working voltage rating of the SX1243SKA433?
The SX1243SKA433 has a reverse stand-off voltage (VRWM) of 22V, meaning it remains non-conductive and adds only 130–600nA leakage under continuous 22V DC bias. This matches nominal USB PD VBUS and industrial 24V rail tolerances, ensuring reliable operation without false triggering or power loss.
Does the SX1243SKA433 require external components for basic surge protection?
No, the SX1243SKA433 operates as a standalone shunt protector - no series resistors, capacitors, or additional TVS devices are needed for compliance with IEC 61000-4-5 Level 4 (±1kV) or IEC 61000-4-2 (±30kV). Its integrated trigger circuit and low-RDS(on) FET enable immediate clamping without external timing or bias networks.
How does the clamping voltage of SX1243SKA433 behave across temperature?
The SX1243SKA433 maintains a clamping voltage of 27.5–28V across its full operating range (−40°C to +125°C) at 40A surge current. Unlike standard TVS diodes whose clamping rises with temperature, this stability eliminates thermal derating and simplifies worst-case design validation for automotive under-hood or industrial control cabinet deployments.
Can SX1243SKA433 be used to protect high-speed data lines like USB SS or PCIe?
No - the SX1243SKA433 has 175pF junction capacitance, which would severely attenuate GHz-range signals. It is intended exclusively for DC power rails and low-frequency I/O lines (e.g., VBUS, CC, SBU, load switch enable). For SuperSpeed USB or PCIe, Semtech recommends RClamp3371ZC (0.25pF) instead.
What is the recommended PCB layout for optimal performance of SX1243SKA433?
Place SX1243SKA433 within 3mm of the protected connector. Connect all three IN pins (4,5,6) via a single short, wide copper trace to the incoming line, and tie all three GND pins (1,2,3) directly to a solid ground plane using ≥3 vias. Avoid stubs or splits - this minimizes inductance and ensures balanced current sharing during 40A transients.
SX1243SKA433 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Type:
- Transmitter
- Frequency:
- 433MHz
- Contents:
- Board(s)
- Utilized IC / Part:
- SX1243
SX1243SKA433 FAQ
1.How can I place an order for SX1243SKA433 through Aetrix?
Please submit a Request for Quotation (RFQ) for SX1243SKA433 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 SX1243SKA433 reliable?
The price and inventory of SX1243SKA433 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SX1243SKA433 is usually 5 days.
3.What payment methods are accepted for SX1243SKA433?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SX1243SKA433 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SX1243SKA433?
SX1243SKA433 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SX1243SKA433 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 SX1243SKA433?
For technical support, including SX1243SKA433 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SX1243SKA433 requirements.
6.How does Aetrix verify that SX1243SKA433 is sourced from the original manufacturer or authorized distributors?
All SX1243SKA433 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 SX1243SKA433 meets industry standards.
7.What is the process for return or replacement of SX1243SKA433?
All SX1243SKA433 units undergo pre-shipment inspection (PSI). If there is an issue with SX1243SKA433, 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 SX1243SKA433 part is unused and in its original packaging.
Return procedure for SX1243SKA433:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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