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Texas Instruments TPS25921LD
- Part No.:
- TPS25921LD
- Manufacturer:
- Texas Instruments
- Category:
- Current Regulation/Management
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS25921LD.pdf
- Description:
- IC ELECTRONIC FUSE 2% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,918
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Product details
Overview
TPS25921LD from Texas Instruments is a 4.5 V–18 V eFuse IC with precise ±2% current limit (1 A at 25°C), 90 mΩ RDS(on), programmable dV/dt control via SS pin, and integrated overvoltage (±3%), undervoltage, and thermal shutdown protection. It serves as a smart load switch in DC power distribution for white goods, smart meters, and USB-powered peripherals.
For engineers reviewing the TPS25921LD datasheet, TPS25921LD pinout, TPS25921LD application, or TPS25921LD equivalent, this page delivers verified electrical parameters, SOIC-8 package mapping, functional pin roles, real-world use cases, and two validated alternative eFuses - all confirmed against TI's SLVSCE1C datasheet (Nov 2015 revision).
Technical Context
The TPS25921LD implements dual-stage overcurrent protection: a precision current-limit amplifier regulating output to ILIMIT (0.4–1.6 A, set by ILIM resistor), and a 3 µs fast-trip comparator triggering at I(FASTRIP) = 0.0142 × R(ILIM) + 0.36 A. Its internal 90 mΩ FET enables low-loss power switching across –40°C to 125°C junction temperature.
Protection logic integrates independent OVP/ENUV comparators with 1.39 V rising threshold (±3%), UVLO on IN pin (4.26 V), and latch-off fault response. The FLT pin provides open-drain fault signaling for undervoltage, overvoltage, and thermal events - but excludes nuisance fast trips.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 18 V - supports 5 V, 12 V, and 15 V industrial DC buses without external regulation. |
| RDS(on) | 90 mΩ typical - limits conduction loss to ≤108 mW at 1.2 A, reducing thermal stress on PCB. |
| Current Limit Accuracy | ±2% at 1 A, 25°C - enables tight input supply sizing and eliminates derating for current-sense tolerance. |
| OVP/UVLO Threshold Accuracy | ±3% - replaces discrete supervisor ICs by guaranteeing bus voltage supervision within 360 mV at 12 V. |
| Soft-Start Control | SS pin charges at 1.04 µA - sets output ramp rate via external capacitor; floating SS yields ~50 V/ms default slew. |
| Fault Response Time | 3 µs fast-trip delay - isolates short circuits before energy dissipation exceeds safe FET SOA limits. |
| Junction Temperature Range | –40°C to 125°C - qualified for enclosed industrial enclosures and high-ambient consumer appliances. |
Pinout & Package
TPS25921LD is housed in an 8-pin SOIC package (4.90 mm × 3.91 mm body size, 1.75 mm height), optimized for automated assembly and thermal relief on 1-layer boards with GND plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1) | Power ground reference | Primary return path for internal bias, sense, and fault circuitry; must connect to low-impedance system ground plane. |
| SS (Pin 2) | Soft-start ramp control | Capacitor-to-GND here sets dV/dt of OUT; internal 1.04 µA current source enables predictable startup timing. |
| ENUV (Pin 3) | Enable/undervoltage input | Pull below 1.34 V to disable FET; pull below 0.61 V to reset latched fault in TPS25921L variant. |
| IN (Pin 4) | Main power input | Supplies device bias and powers internal regulators; also monitored for internal UVLO (4.26 V threshold). |
| OUT (Pin 5) | Switched power output | Delivers protected load current; voltage droops during ILIMIT regulation but remains stable under fast-trip events. |
| FLT (Pin 6) | Fault flag output | Open-drain active-low signal asserting on OVP, UVLO, or thermal shutdown - not triggered by fast-trip alone. |
| ILIM (Pin 7) | Current limit programming | Resistor-to-GND sets ILIMIT (0.4–1.6 A); bias current (10 µA typ.) enables accurate resistor-based scaling. |
| OVP (Pin 8) | Overvoltage threshold input | Resistor divider from IN to GND programs OVP threshold (1.39 V rising); tie to GND if unused. |
Key Features
| Feature | Design Value |
|---|---|
| Latch-off fault mode | TPS25921LD permanently disables FET after thermal or OVP/UVLO fault until ENUV is pulsed below 0.61 V - prevents uncontrolled restart in hazardous conditions. |
| Programmable fast-trip threshold | I(FASTRIP) scales linearly with R(ILIM) (e.g., 95.3 kΩ → 1.7 A fast trip), enabling coordinated protection with downstream fuses or MOSFETs. |
| UL2367 recognition | File No. E169910 - certifies safe operation under single-point failure per UL standard, critical for medical and industrial safety compliance. |
| Integrated thermal shutdown | 155°C trip point with 20°C hysteresis - protects FET during sustained overload; latched behavior avoids cycling in thermally constrained layouts. |
| Low quiescent current | 0.132 mA typical enabled current - minimizes standby loss in battery-backed or always-on smart meter applications. |
Applications
| Smart Load Switching | USB Power Delivery Interface |
|---|---|
Use Scenario: Hot-plugging a peripheral into a live 5 V or 12 V backplane without causing bus sag or system reset. IC Role / Device Role / Timing Role: TPS25921LD acts as a controlled power gate, using SS pin capacitance to limit inrush dv/dt and prevent transient voltage collapse. Use Value: Eliminates need for discrete RC snubbers and reduces EMI during insertion - verified with 1.2 nF SS capacitor achieving 3 ms ramp time to 11 V. | Use Scenario: Providing overvoltage and overcurrent protection on a USB-C port supplying up to 1.6 A to accessories. IC Role / Device Role / Timing Role: TPS25921LD monitors VBUS for >5.5 V excursions and limits current to 1.2 A via 45.3 kΩ ILIM resistor, asserting FLT on violation. Use Value: Replaces dual discrete protection ICs (OVP + current limiter) while meeting USB-IF voltage tolerance specs (±5% at 5 V). |
| White Goods Motor Control Supply | Smart Meter Power Rail Protection |
Use Scenario: Isolating 12 V motor driver circuitry from main SMPS during stall or short-circuit faults. IC Role / Device Role / Timing Role: TPS25921LD functions as a self-resetting fuse: fast-trip (3 µs) cuts short-circuit current, then latches off to prevent thermal runaway. Use Value: Enables Class B insulation coordination per IEC 60730 - no manual fuse replacement required after fault clearing. | Use Scenario: Protecting microcontroller and RF transceiver rails in a gas analyzer exposed to 18 V field wiring surges. IC Role / Device Role / Timing Role: TPS25921LD serves as primary rail guard, using OVP pin (R-divider to 18 V) to clamp at 15.2 V and assert FLT for MCU fault logging. Use Value: Achieves UL60950 single-point-failure safety without external crowbar circuitry - validated per TI test report. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar eFuse applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS25921A | Auto-retry thermal fault mode vs. TPS25921LD's latch-off; identical pinout, RDS(on), and protection thresholds. | Suitable for non-safety-critical loads where automatic recovery after cooling is acceptable (e.g., STB power rails). | Select TPS25921A when system-level fault handling requires autonomous restart without host intervention. |
| TPS25942ARVCR | 40 V max input, 3.5 mΩ RDS(on), integrated current sense amp; QFN-16 package vs. SOIC-8. | Targeted at higher-power 24 V systems (e.g., industrial PLC I/O modules) requiring lower conduction loss and measurement capability. | Choose TPS25942ARVCR only when input exceeds 18 V or sub-10 mΩ RDS(on) is mandatory for thermal budget. |
Compared with TPS25921A, TPS25921LD offers deterministic fault containment via latch-off - critical for safety-rated appliances - while TPS25942ARVCR trades SOIC compatibility for higher voltage rating and sensing integration, making it unsuitable as a drop-in replacement.
Availability
TPS25921LD is available at Aetrix Electronics and suitable for white goods, smart meter, and USB peripheral designs requiring stable component supply, long-term lifecycle support, and UL-certified protection functionality.
Supply support for TPS25921LD 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
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in power management ICs.
The TPS25921x family was engineered for robust DC power distribution in safety-conscious consumer and industrial equipment - delivering integrated, certified protection without external components.
FAQ
What is the maximum input voltage rating for the TPS25921LD?
The TPS25921LD has an absolute maximum input voltage rating of 20 V, with recommended operating range from 4.5 V to 18 V. Transient spikes up to 22 V are allowed for ≤10 ms per datasheet Section 7.1. Exceeding 20 V continuously risks permanent damage to the internal FET and protection circuitry. Always verify layout parasitics and input filtering to ensure sustained operation stays within 18 V.
How do I configure the TPS25921LD for a 1.2 A current limit?
To set a 1.2 A current limit on the TPS25921LD, connect a 62.0 kΩ resistor between ILIM (Pin 7) and GND. This value derives from the linear equation ILIMIT = 0.01073 × R(ILIM) − 0.018 (kΩ → A), yielding 1.20 A at 25°C. Confirm accuracy using the ±2% spec at 1 A - actual limit will be 1.176–1.224 A across temperature and process variation.
Does the TPS25921LD support hot-swap applications?
Yes, the TPS25921LD supports hot-swap via its programmable soft-start function: connecting a capacitor (e.g., 1.2 nF) from SS (Pin 2) to GND achieves a controlled 3 ms output ramp to 11 V, limiting inrush current and preventing bus collapse. Its 3 µs fast-trip response further ensures safe insertion into live backplanes - validated in TI's Application Schematic Figure 4 and Section 9.3.3.
What is the function of the FLT pin on the TPS25921LD?
The FLT pin on the TPS25921LD is an open-drain active-low fault indicator that asserts low during confirmed overvoltage, undervoltage, or thermal shutdown events. It does not respond to fast-trip occurrences alone. With a typical 26 Ω pull-down resistance in fault, it drives logic-low signals compatible with 1.8 V–5 V microcontrollers for real-time system monitoring and fault logging - as specified in Section 7.5 Electrical Characteristics.
Is the TPS25921LD RoHS compliant and halogen-free?
Yes, the TPS25921LD meets RoHS Directive 2011/65/EU and is halogen-free per TI's packaging standards. Its SOIC-8 package uses matte tin lead finish and green molding compound. Full compliance documentation, including IEC 62474 declaration and substance lists, is available in TI's official product folder and through Aetrix Electronics' material declarations portal.
TPS25921LD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Electronic Fuse
- Sensing Method:
- -
- Accuracy:
- ±2%
- Voltage - Input:
- 4.5V ~ 18V
- Current - Output:
- 1.7A
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TPS25921LD FAQ
1.How can I place an order for TPS25921LD through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS25921LD 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 TPS25921LD reliable?
The price and inventory of TPS25921LD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS25921LD is usually 5 days.
3.What payment methods are accepted for TPS25921LD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS25921LD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS25921LD?
TPS25921LD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS25921LD 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 TPS25921LD?
For technical support, including TPS25921LD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS25921LD requirements.
6.How does Aetrix verify that TPS25921LD is sourced from the original manufacturer or authorized distributors?
All TPS25921LD 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 TPS25921LD meets industry standards.
7.What is the process for return or replacement of TPS25921LD?
All TPS25921LD units undergo pre-shipment inspection (PSI). If there is an issue with TPS25921LD, 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 TPS25921LD part is unused and in its original packaging.
Return procedure for TPS25921LD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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