Texas Instruments TPS25921AD

Overview

TPS25921AD from Texas Instruments is a 4.5 V–18 V eFuse IC with precise current limiting, overvoltage protection (OVP), undervoltage lockout (UVLO), and programmable soft-start. It features 90 mΩ R_DS(on), ±2% current limit accuracy at 1 A (25°C), and an open-drain FLT fault flag. Used in white goods, smart meters, and USB power switches for robust hot-swap and inrush control.

For engineers reviewing the TPS25921AD datasheet, TPS25921AD pinout, TPS25921AD application, or TPS25921AD equivalent, this page delivers verified electrical specs, SOIC-8 package mapping, functional timing behavior, thermal shutdown recovery mode, and real-world load-switching design implications - all confirmed against TI's SLVSCE1C revision C datasheet.

Technical Context

The TPS25921AD integrates a precision current-sense amplifier, fast-trip comparator (3 µs response), and thermal shutdown circuitry (155°C trip, 20°C hysteresis). Its dual overcurrent thresholds-programmable ILIMIT (0.4–1.6 A) and I_FASTRIP (1.42×R_ILIM + 0.36 A)-enable differentiated overload vs. short-circuit handling without external components.

It implements programmable dV/dt via SS pin (capacitor-to-GND), gain of 4.86 V/V from SS to OUT, and independent OVP/ENUV resistor-divider inputs with ±3% threshold accuracy. The device operates across –40°C to 125°C junction temperature and supports auto-retry fault recovery (TPS25921A variant).

Key Specifications

Pinout & Package

TPS25921AD 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 dissipation on 1-layer boards with GND plane (R_θJA = 120.8°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar eFuse applications.

Compared with TPS25921L, TPS25921AD provides automatic recovery from thermal faults - critical for unattended appliances - while TPS25942ARVCR trades soft-start flexibility for higher voltage rating and lower R_DS(on), making it unsuitable for cost-sensitive 12 V consumer designs requiring dV/dt control.

Availability

TPS25921AD is available at Aetrix Electronics and suitable for white goods, smart metering, and USB-C power delivery applications requiring stable component supply, long-term lifecycle support, and full traceability.

Supply support for TPS25921AD 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The TPS25921x product line was designed specifically for intelligent DC power distribution - integrating precise current limiting, voltage supervision, and fault reporting into a single SOIC-8 eFuse for space-constrained, high-reliability systems.

FAQ

What is the maximum input voltage rating for the TPS25921AD?

The TPS25921AD has an absolute maximum input voltage rating of 20 V continuous and 22 V for 10 ms transients. Its recommended operating range is 4.5 V to 18 V. Exceeding 20 V risks permanent damage per Absolute Maximum Ratings (Section 7.1). Always verify input rail stability and transient suppression in the final design before deploying TPS25921AD.

How do I set the current limit to 1.2 A on the TPS25921AD?

To set ILIMIT = 1.2 A on the TPS25921AD, connect a 75.2 kΩ resistor from ILIM (Pin 7) to GND. This value derives from Equation 4 in the datasheet: ILIMIT = 10.73×10⁻³ × R_ILIM − 0.018, solved for R_ILIM. Use 1% tolerance metal-film resistors and route the ILIM trace away from noisy signals to maintain ±2% accuracy.

Does the TPS25921AD support adjustable overvoltage protection?

Yes, the TPS25921AD supports adjustable OVP via an external resistor divider from IN to OVP (Pin 8) to GND. With ±3% threshold accuracy and 1.39 V internal reference, a 100 kΩ/10.2 kΩ divider sets OVP to 15.0 V. Tie OVP to GND to disable the function. Do not leave the pin floating - it must be actively terminated.

What is the purpose of the SS pin on the TPS25921AD, and how do I use it?

The SS (soft-start) pin on the TPS25921AD controls output voltage ramp rate via an external capacitor to GND. With 1 µA internal charge current and 4.86 V/V gain, a 1.2 nF capacitor yields ~3 ms ramp time to 12 V. Leaving SS floating defaults to ~50 V/ms slew rate. Avoid routing SS near switching nodes to prevent noise-induced dV/dt errors.

Is the TPS25921AD RoHS-compliant and lead-free?

Yes, the TPS25921AD is RoHS-compliant and lead-free, meeting JEDEC J-STD-020 moisture sensitivity level 3 (MSL-3) and TI's Green Packaging standards. Full compliance documentation, including substance declarations and test reports, is available in the TPS25921A product folder on ti.com.