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Semtech Corporation PFM50A
- Part No.:
- PFM50A
- Manufacturer:
- Semtech Corporation
- Category:
- Single Diodes
- Package:
- Axial
- Datasheet:
-
PFM50A.pdf
- Description:
- DIODE GEN PURP 5KV 92MA AXIAL
- Quantity:
- Payment:
- Shipping:
Inventory:9,141
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Product details
Overview
PFM50A 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), and stable 27.5–28V clamping voltage across temperature and current range - deployed in USB Type-C PD input protection and industrial load switch front-end circuits.
For engineers reviewing the PFM50A datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DFN-6 package layout guidance, real-world clamping behavior vs. conventional TVS, and validated alternatives for 22V bus protection in USB PD, IoT, and industrial equipment designs.
Technical Context
The PFM50A uses a surge-rated FET as its primary protection element, activated by an integrated precision trigger circuit that turns on the shunt path when transient voltage exceeds breakdown threshold. Unlike standard TVS diodes, its clamping voltage remains nearly constant due to ultra-low dynamic resistance (20 mΩ) and decreasing RDS(on) under surge conditions.
It operates over –40°C to +125°C with <600 nA reverse leakage at 22V, 175 pF junction capacitance at 22V/1MHz, and meets IEC 61000-4-4 (±4kV EFT), IEC 61000-4-5 (±1kV unsymmetrical, 40A 8/20μs), and IEC 61000-4-2 (±30kV contact/air) standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage | 22 V - defines maximum continuous DC operating voltage of protected line without leakage or conduction. |
| Clamping Voltage | 27.5–28 V at 40A (8/20μs) - ensures downstream ICs (e.g., USB PD controllers) remain below damage threshold during worst-case surges. |
| Peak Pulse Current | 40 A (8/20μs) - supports compliance with IEC 61000-4-5 Level 4 industrial surge immunity requirements. |
| ESD Withstand | ±30 kV contact & air (IEC 61000-4-2) - eliminates need for external ESD staging in high-reliability portable interfaces. |
| Dynamic Resistance | 20 mΩ - enables flat clamping curve and minimizes voltage overshoot during fast-rising transients. |
| Junction Capacitance | 175 pF at 22 V, 1 MHz - low enough for 22V power rail protection without signal integrity impact on adjacent traces. |
Pinout & Package
PFM50A is housed in a RoHS-compliant, halogen-free DFN package measuring 1.6 mm × 1.6 mm × 0.55 mm with exposed thermal pad (no internal thermal pad required; energy dissipated in silicon). All six terminals are surface-mount; pins must be fully connected per layout guidelines to achieve rated surge performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 | GND | Common ground return path for surge current; all three must be soldered and vias used to inner ground plane to minimize inductance. |
| 4, 5, 6 | IN | Protected line input (e.g., VBUS in USB PD); parallel connection ensures current sharing and full 40A rating. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-clamp architecture | Clamping voltage stays within 27.5–28 V from 1A to 40A and –40°C to +125°C - eliminates derating uncertainty in thermal design. |
| FET-based shunt topology | Replaces traditional pn-junction TVS with active switching; avoids thermal runaway and enables higher IPP in same footprint. |
| Low dynamic resistance | 20 mΩ measured between 1A–40A (8/20μs) - reduces voltage overshoot during sub-100ns ESD events. |
| High-energy ESD immunity | ±30 kV contact/air per IEC 61000-4-2 - exceeds automotive and industrial ESD test requirements without external staging. |
Applications
| USB Type-C Power Delivery Protection | Industrial Load Switch Input Protection |
|---|---|
Use Scenario: Protecting 20–22V VBUS lines in USB-C receptacles where PD negotiation occurs and lightning-induced surges may exceed ±1kV. IC Role / Device Role / Timing Role: Primary front-end EOS suppressor placed directly at connector, diverting surge current to ground before reaching PD controller or load switch. Use Value: Maintains clamping at ≤28 V across full temperature range - prevents false OVP trips and guarantees PD controller survival under 40A surge. |
Use Scenario: Safeguarding input of industrial-grade load switches (e.g., HS2950P) in remote meters, robotics, and factory automation systems exposed to 40A lightning surges. IC Role / Device Role / Timing Role: High-current shunt protector placed upstream of load switch FET to limit drain-source voltage during transients. Use Value: Keeps VDS below 30 V during 8/20μs surges - avoids gate oxide damage and ensures load switch functional continuity after event. |
| IoT Edge Node Power Bus Protection | Storage Device 22V Rail Protection |
Use Scenario: Securing 22V auxiliary rails in battery-backed IoT gateways and edge AI modules subjected to ESD during field servicing or cable hot-plug. IC Role / Device Role / Timing Role: Single-device solution for both ESD and surge, replacing multi-stage TVS+MOV approaches in space-constrained PCBs. Use Value: Delivers ±30kV ESD and 40A surge protection in 1.6×1.6mm footprint - reduces BOM count and layout area by >50% vs. discrete TVS arrays. |
Use Scenario: Protecting 22V power inputs in NVMe SSD enclosures and enterprise storage backplanes where transient coupling occurs via shared chassis grounds. IC Role / Device Role / Timing Role: Low-capacitance (175 pF), high-power suppressor isolating transient energy from sensitive PMIC and controller ICs. Use Value: Limits clamping to 28 V while adding only 175 pF to rail - avoids destabilizing 22V buck converters or causing false brown-out detection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TDS2211P | Identical device - same die, same DFN-6 package, same marking code T22; PFM50A is Semtech's alternate orderable part number for TDS2211P. | No functional difference; used interchangeably in USB PD reference designs and industrial schematics. | Select PFM50A when sourcing through authorized distributors using Semtech's secondary part numbering scheme. |
| SMAJ22A | Standard unidirectional TVS diode; 22V VRWM, 35.5V VC @ 24.7A, 1.5W PPPK; no constant-clamp behavior - VC rises with current and temperature. | Higher clamping (≥35.5V) limits use to non-PD 22V rails; unsuitable for high-temp industrial environments where VC drift exceeds safe margin. | Choose only if cost sensitivity outweighs clamping stability; requires thermal derating above 85°C and cannot support 40A surges. |
Compared with TDS2211P (identical function and specs) and SMAJ22A (higher, temperature-sensitive clamping), PFM50A delivers guaranteed 28 V clamping at 40A across –40°C to +125°C - enabling robust, single-component protection for USB PD, industrial load switches, and 22V IoT power rails without layout or thermal compromises.
Availability
PFM50A is available at Aetrix Electronics and suitable for USB Type-C PD interfaces, industrial load switch inputs, and 22V IoT power bus protection requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for PFM50A 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 protection, sensing, and signal integrity.
PFM50A belongs to Semtech's Transient Diverting Suppressor (TDS) product line - engineered specifically to replace conventional TVS diodes in high-voltage, high-surge industrial and USB PD applications where stable clamping and temperature resilience are critical.
FAQ
What is the exact package type and dimensions of the PFM50A?
The PFM50A is supplied in a 6-pin DFN package measuring 1.6 mm × 1.6 mm × 0.55 mm with exposed pad. Pin 1 is marked by a laser dot; pins 1–3 are GND, pins 4–6 are IN. Full connection of all six terminals is mandatory to achieve the rated 40A peak pulse current capability per the official Semtech datasheet for PFM50A.
Does the PFM50A meet IEC 61000-4-5 surge immunity standards?
Yes, the PFM50A is rated for ±1 kV (1.2/50 μs voltage, 8/20 μs current, RS = 42 Ω) and 40 A (8/20 μs) per IEC 61000-4-5, making it suitable for Level 4 industrial surge protection. Its constant-clamp architecture ensures compliance remains valid across –40°C to +125°C ambient, unlike standard TVS devices whose clamping degrades with temperature.
How does the clamping voltage of the PFM50A compare to standard TVS diodes at 40A?
The PFM50A clamps at 27.5–28 V at 40A (8/20 μs), whereas a typical 22V TVS like SMAJ22A clamps at ≥35.5 V under identical conditions - a 7.5–8 V advantage. This margin prevents overvoltage damage to USB PD controllers and industrial load switches, especially at elevated temperatures where TVS clamping rises further.
Can the PFM50A be used for bidirectional signal line protection?
No - the PFM50A is a unidirectional suppressor intended for 22V DC power or I/O lines referenced to ground. It is not designed for AC or bidirectional data lines (e.g., USB SS, DP/DM). For those, Semtech recommends low-capacitance TVS devices such as RClamp3371ZC, as specified in the PFM50A's official application notes.
Is the PFM50A pin-compatible with other Semtech TDS devices?
The PFM50A shares the same DFN-6 footprint and pinout (GND on pins 1–3, IN on pins 4–6) with TDS2211P and TDS2411P, but voltage ratings differ: TDS2411P is rated for 24V VRWM. Substituting PFM50A for TDS2411P in a 24V system risks premature conduction; always verify working voltage match before replacement.
PFM50A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Series:
- -
- Package/Case:
- Axial
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 5000 V
- Current - Average Rectified (Io):
- 92mA
- Voltage - Forward (Vf) (Max) @ If:
- 12.5 V @ 25 mA
- Speed:
- Small Signal =< 200mA (Io), Any Speed
- Reverse Recovery Time (trr):
- 250 ns
- Current - Reverse Leakage @ Vr:
- 500 nA @ 5000 V
- Capacitance @ Vr, F:
- 2pF @ 50V, 1KHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- Axial
- Operating Temperature - Junction:
- -
PFM50A FAQ
1.How can I place an order for PFM50A through Aetrix?
Please submit a Request for Quotation (RFQ) for PFM50A 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 PFM50A reliable?
The price and inventory of PFM50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PFM50A is usually 5 days.
3.What payment methods are accepted for PFM50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PFM50A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PFM50A?
PFM50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PFM50A 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 PFM50A?
For technical support, including PFM50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PFM50A requirements.
6.How does Aetrix verify that PFM50A is sourced from the original manufacturer or authorized distributors?
All PFM50A 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 PFM50A meets industry standards.
7.What is the process for return or replacement of PFM50A?
All PFM50A units undergo pre-shipment inspection (PSI). If there is an issue with PFM50A, 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 PFM50A part is unused and in its original packaging.
Return procedure for PFM50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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