Texas Instruments TPS78825DBVR

Overview

TPS78825DBVR from Texas Instruments is a 2.5 V, 150-mA low-noise LDO voltage regulator in SOT-23-5 package, featuring programmable slew-rate control via SR pin to limit in-rush current in USB-powered systems. It delivers 56 µV_RMS output noise with 10 µF output capacitor, 150 mV typical dropout at full load, and operates across –40°C to 125°C junction temperature range.

For engineers reviewing the TPS78825DBVR datasheet, TPS78825DBVR pinout, TPS78825DBVR application, or TPS78825DBVR equivalent, key selection criteria include ultra-low quiescent current (17 µA active / 1 µA standby), PMOS pass element architecture, input voltage range (2.7–13.5 V), and explicit USB start-up current control capability.

Technical Context

The TPS78825DBVR uses a PMOS pass transistor-replacing traditional PNP-to achieve low, load-proportional dropout voltage (150 mV @ 150 mA). Its internal 150-kΩ resistor forms an RC filter with external SR capacitor to program output slew rate, directly addressing large-capacitance USB load transients.

It integrates logic-enabled sleep mode (EN pin active-low) for 1 µA standby current, overcurrent limiting (~350 mA peak), and thermal shutdown (~165°C trip). Output stability requires 4.7–10 µF output capacitor with ESR between 0.2 Ω and 10 Ω, per TI's validated design guidance.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9 mm × 1.6 mm × 1.15 mm body, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78825DBVR, TPS78825DBVT offers identical performance in smaller packaging volume but lower unit economics at scale, while TLS850F2BTV50 trades USB-specific in-rush control for automotive robustness and wider input range - making it unsuitable for USB hot-plug compliance without external circuitry.

Availability

TPS78825DBVR is available at Aetrix Electronics and suitable for USB peripheral power management, portable medical sensor nodes, industrial docking stations, and automotive infotainment hubs requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for TPS78825DBVR 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, embedded processing, and connectivity technologies, with decades of LDO design heritage and broad industrial qualification.

The TPS788xx product line was engineered specifically for USB-compliant low-noise, low-quiescent-power regulation in space-constrained portable and embedded systems - prioritizing in-rush control, thermal resilience, and noise performance over generic voltage regulation.

FAQ

What is the minimum input voltage required for stable operation of the TPS78825DBVR?

The TPS78825DBVR requires a minimum input voltage of 2.7 V or (V_O(typ) + 1 V) = 3.5 V, whichever is greater. Since its nominal output is 2.5 V, the effective minimum input is 3.5 V under typical load conditions. This ensures sufficient headroom for the 150 mV typical dropout voltage and maintains regulation across temperature and load variations. The absolute maximum input is 13.5 V.

How does the SR pin on the TPS78825DBVR control in-rush current during USB start-up?

The SR pin on the TPS78825DBVR connects to an internal 150-kΩ resistor forming an RC network with an external capacitor. This network controls the slew rate of the output voltage rise, directly limiting peak in-rush current into large load capacitances (e.g., 10–22 µF USB port decoupling). For example, a 0.01 µF SR capacitor yields ~10 ms startup, while 0.47 µF extends it to ~300 ms - preventing USB host overcurrent faults.

Can the TPS78825DBVR be used with ceramic output capacitors below 4.7 µF?

No - the TPS78825DBVR requires a minimum 4.7 µF output capacitor for guaranteed stability. Capacitors smaller than this value demand extremely tight ESR control (0.2–10 Ω) and increase risk of oscillation. TI explicitly recommends ≥4.7 µF tantalum or ceramic capacitors; multilayer ceramics may require a series resistor to raise ESR into the stable range. Using <4.7 µF voids stability guarantees per the datasheet.

What is the thermal shutdown behavior of the TPS78825DBVR under sustained overload?

When junction temperature exceeds ~165°C, the TPS78825DBVR activates thermal shutdown, disabling the output until die temperature falls below ~140°C. During overload, current limiting engages first (clamping peak output to ~350 mA), causing power dissipation that may trigger thermal shutdown if ambient and PCB thermal resistance prevent adequate heat removal. Recovery is automatic and does not require cycling EN.

Does the TPS78825DBVR support reverse current flow from OUT to IN, and how should it be managed?

Yes - the TPS78825DBVR's PMOS pass element includes a built-in back-channel diode that conducts reverse current when V_IN < V_OUT (e.g., during power-down). This current is not internally limited and can damage upstream sources. To prevent uncontrolled reverse conduction, TI recommends adding an external Schottky diode in series with the IN rail or using an ideal diode controller when bidirectional power paths exist.