My Inquiry
My Account
Semtech Corporation SC644ULTRT
- Part No.:
- SC644ULTRT
- Manufacturer:
- Semtech Corporation
- Category:
- LED Drivers
- Package:
- 20-VFQFN Exposed Pad
- Datasheet:
-
SC644ULTRT.pdf
- Description:
- IC LED DRIVER RGLTR 25MA 20MLPQ
- Quantity:
- Payment:
- Shipping:
Inventory:2,603
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SC644ULTRT 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, 20mΩ dynamic resistance, and 175pF junction capacitance. It protects USB PD, USB Type-C VBus, and load switch inputs in industrial and portable electronics.
For engineers reviewing the SC644ULTRT datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DFN-6 package layout guidance, temperature-stable clamping behavior, and direct alternatives for 22V bus protection in high-reliability designs.
Technical Context
The SC644ULTRT uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that turns on the shunt path when transient voltage exceeds breakdown. Unlike conventional TVS diodes, its clamping voltage remains nearly constant across 24–40A peak pulse current due to decreasing RDS(on) under surge conditions.
It operates over –40°C to +125°C with stable 27.5–28V clamping at 40A, 22V reverse stand-off voltage, and <600nA leakage at VRWM - enabling robust protection in thermally demanding environments without derating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage | 22V - supports continuous operation on USB PD and industrial 20–22V rails without leakage or degradation. |
| Clamping Voltage | 27.5–28V at 40A (8/20μs) - maintains safe margin below typical 30V+ IC damage thresholds under worst-case surge. |
| Peak Pulse Current | 40A (8/20μs) - meets IEC 61000-4-5 Level 4 surge immunity for industrial equipment and USB PD systems. |
| ESD Withstand | ±30kV contact & air (IEC 61000-4-2) - eliminates need for secondary ESD stages in connector-facing protection. |
| Dynamic Resistance | 20mΩ - enables low-voltage overshoot during fast transients, critical for protecting sensitive load switches and PD controllers. |
| Junction Capacitance | 175pF at 22V - compatible with DC/low-frequency power line protection; not intended for high-speed data lines. |
Pinout & Package
SC644ULTRT is housed in a RoHS-compliant DFN-6 package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no solder requirement). All six terminals are electrically active: three dedicated ground pins and three parallel input pins - all must be connected for full 40A surge rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 | GND | Low-inductance ground return path; multiple vias recommended to minimize parasitic inductance during surge conduction. |
| 4, 5, 6 | IN | Parallel-connected protected line input; all three pins carry equal share of 40A surge current to reduce current density and thermal stress. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-clamp architecture | Clamping voltage varies ≤0.5V from 24A to 40A - eliminates design uncertainty from TVS voltage drift under surge. |
| Temperature-stable clamping | 27.5–28V clamping maintained from –40°C to +125°C - removes thermal derating calculations for industrial deployments. |
| Ultra-low dynamic resistance | 20mΩ enables sub-1V overshoot during 100A/μs dV/dt events - critical for protecting gate drivers and e-fuse ICs. |
| High-energy EOS handling | 1120W peak pulse power (8/20μs) - sustains repeated lightning-surge events without parametric shift or failure. |
Applications
| USB Type-C Power Delivery Bus Protection | Industrial Load Switch Input Protection |
|---|---|
Use Scenario: Protecting 20V–22V VBus lines in USB-C receptacles against ESD, lightning surges, and hot-plug transients. IC Role / Device Role / Timing Role: Primary shunt protector placed directly at connector, clamping transients before they reach PD controller or power multiplexer. Use Value: Maintains 27.5V clamping at full 40A even at 125°C - prevents overvoltage damage to USB PD controllers rated for ≤30V absolute maximum. |
Use Scenario: Safeguarding input pins of high-side load switches (e.g., HS2950P) in remote meters, robotics, and IoT hubs. IC Role / Device Role / Timing Role: Front-end transient diverter that limits voltage seen by the load switch's internal FET during EOS events. Use Value: Prevents gate oxide rupture and drain-source avalanche in load switches by holding clamp voltage well below their 30–40V breakdown limit. |
| 22V Industrial Power Rail Protection | Notebook/Tablet DC Power Input Protection |
Use Scenario: Securing 22V auxiliary rails in programmable logic controllers, motor drives, and factory automation modules. IC Role / Device Role / Timing Role: Single-device solution replacing multi-stage TVS+MOV networks for compact, repeatable surge response. Use Value: Delivers 40A surge capability in 2.56mm² footprint - reduces board area by >60% versus discrete TVS+GDT solutions. |
Use Scenario: Hardening 20V DC-in ports on ultrabooks and tablets against accidental adapter misconnection and ESD. IC Role / Device Role / Timing Role: Standalone overvoltage suppressor between barrel jack and system PMIC input. Use Value: Enables compliance with IEC 61000-4-2/4-5 without compromising thin-profile mechanical design constraints. |
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 electrical specs, same DFN-6 package, identical marking and reel packaging - confirmed drop-in replacement per Semtech documentation. | No functional difference; validated for identical USB PD, load switch, and industrial 22V rail use cases. | Select TDS2211P when sourcing from Semtech-authorized channels with traceable lot history. |
| SP1002-02WTG | 22V working voltage, 30A IPP (8/20μs), 33V clamping at 30A, SOD-323 package - higher clamping, lower surge rating, smaller footprint. | Suitable only for lower-energy applications; insufficient for IEC 61000-4-5 Level 4 or sustained 40A surges. | Choose SP1002-02WTG only if board space is constrained and peak surge requirements are ≤30A. |
Compared with TDS2211P, SC644ULTRT offers identical performance and form factor, enabling seamless substitution; versus SP1002-02WTG, SC644ULTRT provides 33% higher surge current rating and 5.5V lower clamping - critical for protecting next-generation 22V PD controllers and high-density load switches.
Availability
SC644ULTRT is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial load switch interfaces, and 22V DC power rail protection requiring stable component supply, long-term lifecycle support, and full compliance traceability.
Supply support for SC644ULTRT 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 analog and mixed-signal ICs for precision protection, signal integrity, and wireless infrastructure.
The SC644ULTRT belongs to Semtech's Transient Diverting Suppressor (TDS) family, engineered to replace conventional TVS diodes in high-reliability 22V power-line protection where stable clamping and temperature insensitivity are mandatory.
FAQ
What is the exact package type and dimensions of SC644ULTRT?
SC644ULTRT uses a 6-pin DFN package measuring 1.6mm × 1.6mm × 0.55mm with no exposed thermal pad required. Pins 1–3 are GND; pins 4–6 are IN. The land pattern matches Semtech's standard DFN-6 outline drawing, and all six pins must be soldered for full 40A surge rating. Pin 1 is marked with a laser dot.
Does SC644ULTRT meet IEC 61000-4-5 Level 4 surge immunity?
Yes, SC644ULTRT is rated for 40A peak pulse current with 8/20μs waveform per IEC 61000-4-5, satisfying Level 4 (4kV open-circuit, 2Ω source impedance) for industrial equipment. Its 27.5–28V clamping at 40A ensures downstream components remain within safe operating voltage limits during full-rated surge events.
How does SC644ULTRT differ from standard TVS diodes in clamping behavior?
Unlike standard TVS diodes whose clamping voltage rises linearly with peak current (VC = VBR + IPP × RDYN), SC644ULTRT uses a triggered FET architecture that maintains near-constant 27.5–28V clamping from 24A to 40A. This eliminates design margin uncertainty and improves protection predictability across varying surge magnitudes.
Can SC644ULTRT be used on high-speed data lines like USB SuperSpeed or PCIe?
No, SC644ULTRT is not suitable for high-speed data lines. Its 175pF junction capacitance would severely degrade signal integrity on differential pairs operating above ~10MHz. It is strictly intended for DC or low-frequency power and control lines such as USB PD VBus, load switch inputs, or 22V industrial rails.
What is the maximum operating temperature range for SC644ULTRT?
SC644ULTRT is specified for continuous operation from –40°C to +125°C ambient temperature. Its clamping voltage remains stable across this full range - unlike conventional TVS devices, which exhibit increasing clamping voltage and decreasing surge current capability as temperature rises.
SC644ULTRT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Series:
- SemPulse®
- Package/Case:
- 20-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Switched Capacitor (Charge Pump)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 2.9V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 2.5V ~ 5.25V
- Current - Output / Channel:
- 25mA
- Frequency:
- -
- Dimming:
- -
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-MLPQ-UT (3x3)
SC644ULTRT FAQ
1.How can I place an order for SC644ULTRT through Aetrix?
Please submit a Request for Quotation (RFQ) for SC644ULTRT 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 SC644ULTRT reliable?
The price and inventory of SC644ULTRT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SC644ULTRT is usually 5 days.
3.What payment methods are accepted for SC644ULTRT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SC644ULTRT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SC644ULTRT?
SC644ULTRT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SC644ULTRT 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 SC644ULTRT?
For technical support, including SC644ULTRT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SC644ULTRT requirements.
6.How does Aetrix verify that SC644ULTRT is sourced from the original manufacturer or authorized distributors?
All SC644ULTRT 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 SC644ULTRT meets industry standards.
7.What is the process for return or replacement of SC644ULTRT?
All SC644ULTRT units undergo pre-shipment inspection (PSI). If there is an issue with SC644ULTRT, 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 SC644ULTRT part is unused and in its original packaging.
Return procedure for SC644ULTRT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SC644ULTRT Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
Tech Hub
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
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…
