Texas Instruments TPS78825DBVT

Overview

TPS78825DBVT from Texas Instruments is a 2.5 V, 150-mA low-noise LDO voltage regulator in a 5-pin SOT-23 (DBV) package, featuring programmable slew-rate control via the SR pin to limit in-rush current during USB power-up. It delivers 56 µVRMS output noise with a 10 µF output capacitor, 150 mV typical dropout at 150 mA, and only 17 µA quiescent current under load - optimized for portable USB-powered devices requiring stable, low-noise rail generation.

For engineers reviewing the TPS78825DBVT datasheet, TPS78825DBVT pinout, TPS78825DBVT application, or TPS78825DBVT equivalent, key selection considerations include its PMOS pass element architecture, 1 µA standby current, ±2.5% output voltage accuracy over temperature and load, and explicit stability requirements for 4.7–10 µF output capacitors with 0.2–10 Ω ESR.

Technical Context

The TPS78825DBVT uses a PMOS pass transistor instead of a traditional PNP, enabling ultra-low dropout (150 mV @ 150 mA) directly proportional to load current. Its internal 150 kΩ resistor forms an RC filter with an external capacitor on the SR pin to program output voltage slew rate - critical for managing in-rush into large USB load capacitances.

It integrates active-low enable (EN), thermal shutdown, and current limiting (350 mA peak), with operation across –40°C to 125°C junction temperature. The device requires no input capacitor but specifies strict output capacitor ESR (0.2–10 Ω) and minimum 4.7 µF capacitance for loop stability - deviations risk oscillation per Figures 12–13.

Key Specifications

Pinout & Package

TPS78825DBVT is housed in a 5-pin SOT-23 (DBV) surface-mount package with standard JEDEC MO-178AC outline, 1.6 mm × 2.9 mm footprint, and 1.0 mm height. Pin 1 (IN) is located at the top-left corner when the marking dot is oriented top-left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78825DBVT, TPS78833DBVT offers identical performance at 3.3 V output and drop-in PCB compatibility, while MCP1700T-2502E/MB trades away slew control and noise performance for lower quiescent current and cost - making it viable only in non-USB, low-noise-tolerant designs.

Availability

TPS78825DBVT is available at Aetrix Electronics and suitable for USB peripheral power, portable medical sensors, industrial I/O modules, and automotive diagnostic tools requiring stable component supply with guaranteed long-term sourcing.

Supply support for TPS78825DBVT 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and personal electronics markets.

The TPS788xx product line was designed specifically for USB-powered portable equipment, emphasizing low-noise regulation, in-rush current control, and ultra-low quiescent current in miniature SOT-23 packaging.

FAQ

What is the minimum input voltage required for TPS78825DBVT to regulate 2.5 V at 150 mA?

The minimum input voltage for TPS78825DBVT is calculated as VO(max) + VDO(max). With VO(max) = 2.575 V and VDO(max) = 300 mV (per datasheet Table), VI(min) = 2.875 V. However, the datasheet explicitly states the absolute minimum VI is 2.7 V - so 2.875 V is the practical minimum for full 150 mA regulation. Below that, dropout behavior begins.

Can TPS78825DBVT operate with a 1 µF output capacitor?

No - the TPS78825DBVT requires a minimum 4.7 µF output capacitor with ESR between 0.2 Ω and 10 Ω for closed-loop stability. Using 1 µF violates the design requirement and risks oscillation, as confirmed by Figures 12–13 showing instability regions below 4.7 µF. Solid tantalum or multilayer ceramic caps meeting ESR specs are acceptable.

Does TPS78825DBVT support reverse current protection?

TPS78825DBVT does not include reverse current blocking. Its PMOS pass transistor has an intrinsic body diode that conducts from OUT to IN when VI < VO (e.g., during power-down). This can cause backfeed into upstream supplies. External protection - such as a series Schottky diode or ideal diode controller - is required if reverse current must be prevented.

What is the purpose of the SR pin on TPS78825DBVT, and how is it used?

SR (Slew Rate) is an input pin connected internally to a 150 kΩ resistor. Adding an external capacitor (0.01–0.47 µF) creates an RC network that slows the output voltage ramp during startup, limiting in-rush current into large load capacitances - essential for compliance with USB 2.0 port current limits. Larger C(SR) yields slower startup (e.g., 300 ms with 0.47 µF).

Is TPS78825DBVT RoHS compliant and lead-free?

Yes - TPS78825DBVT is RoHS compliant and features NiPdAu (NIPDAU) lead finish. Per TI's Packaging Information Addendum, it carries MSL Level-1 rating (unlimited floor life) and is qualified for reflow up to 260°C peak. The part marking "PGZI" and tape-and-reel packaging (250 units) confirm full production status and environmental compliance.