Texas Instruments TPS25221DBVT

Overview

TPS25221DBVT from Texas Instruments is a 2.5-V to 5.5-V, 2-A continuous current-limited power-distribution switch in SOT-23-6 package, featuring programmable current limit (275 mA–2.7 A), 70-mΩ typical R_DS(on), 1.5-µs short-circuit response, and reverse-current blocking when disabled - used for USB port protection in laptops, hubs, and set-top boxes.

For engineers reviewing the TPS25221DBVT datasheet, TPS25221DBVT pinout, TPS25221DBVT application, or TPS25221DBVT equivalent, key selection considerations include adjustable overcurrent threshold via external resistor, 8-ms fault deglitching, thermal shutdown at 145°C/165°C, UL 60950/62368 recognition, and ESD robustness (±15-kV air-gap per IEC 61000-4-2).

Technical Context

The TPS25221DBVT integrates an internal charge pump to drive its N-channel MOSFET gate above source potential, enabling full enhancement down to 2.5-V input. Its current-sense amplifier monitors load current continuously and forces the FET into saturation during overload, maintaining constant output current while reducing V_OUT.

It implements dual thermal protection: current-limit-triggered shutdown at 145°C (with 20°C hysteresis) and ambient-triggered shutdown at 165°C. Fault reporting uses an open-drain FAULT pin with 8-ms deglitching for overcurrent events but immediate assertion for overtemperature.

Key Specifications

Pinout & Package

SOT-23-6 package (2.90 mm × 1.60 mm), thermally enhanced with exposed GND-connected pad. Pin 1 = IN, Pin 2 = GND, Pin 3 = EN, Pin 4 = FAULT, Pin 5 = ILIM, Pin 6 = OUT.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-limiting power switch applications.

Compared with TPS25221DBVT, TPS2553DBVR trades programmability for simplicity and reduced BOM count, while TPS25221DRV offers identical functionality in a thermally superior package - choice depends on whether adjustability or thermal performance is the primary constraint.

Availability

TPS25221DBVT is available at Aetrix Electronics and suitable for USB port protection, self-powered hub designs, and consumer electronics power management requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for TPS25221DBVT 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 company specializing in analog, embedded processing, and connectivity technologies, with leadership in power management ICs for computing and consumer applications.

The TPS25221DBVT belongs to TI's USB power-switch product line, designed specifically for robust, standards-compliant USB port protection in laptops, hubs, and entertainment systems - emphasizing programmability, safety certification, and fault resilience.

FAQ

What is the minimum input voltage required for TPS25221DBVT to operate?

The TPS25221DBVT requires a minimum input voltage of 2.5 V to operate, with undervoltage lockout (UVLO) releasing at 2.47 V (typical) and 45 mV hysteresis. Below this threshold, the internal power switch remains disabled to prevent unstable regulation. This ensures clean startup and avoids brownout-induced faults in USB-powered systems where input voltage may sag under load.

How do I calculate the R_ILIM resistor value for a desired current limit on TPS25221DBVT?

For TPS25221DBVT, use the equation I_OS (mA) ≈ 56850 / R_ILIM(kΩ) for nominal threshold, where R_ILIM must be between 20 kΩ and 210 kΩ. For example, to achieve ~1.0 A, select R_ILIM ≈ 56.9 kΩ (1% tolerance). Always verify final setting with worst-case tolerance and temperature drift using Figure 24 from the datasheet, as accuracy is ±6.5% at 1.7 A.

Does TPS25221DBVT support reverse current blocking, and under what conditions?

Yes, TPS25221DBVT provides reverse current blocking when the EN pin is driven low (disabled state), preventing current flow from OUT to IN. This feature is inherent to its N-channel MOSFET architecture with integrated gate control. Reverse blocking does not occur during normal enabled operation - it is strictly active only when the device is turned off, making it suitable for USB bus isolation and preventing backfeed in multi-source systems.

What is the purpose of the 8-ms deglitch on the FAULT pin of TPS25221DBVT?

The 8-ms deglitch on the FAULT pin of TPS25221DBVT filters out transient overcurrent events - such as inrush into 120-µF USB hub capacitance - that would otherwise cause nuisance fault assertions. It ensures FAULT only asserts after sustained overload (>8 ms), improving system reliability. The deglitch is applied only to overcurrent faults; overtemperature faults assert FAULT immediately without delay.

Can TPS25221DBVT be used in a 3.3-V system, and what are the implications?

Yes, TPS25221DBVT supports 3.3-V input operation within its 2.5-V to 5.5-V range. At 3.3 V, R_DS(on) increases slightly (to ~110 mΩ max over temperature), raising conduction loss - e.g., 363 mW at 2 A - which demands careful thermal design. Enable threshold (V_IH = 1.7 V) remains compatible with 3.3-V logic, and all protections (UVLO, thermal, fault) function normally.