Texas Instruments TLV74028PDQNR

Overview

TLV74028PDQNR from Texas Instruments is a 2.8V fixed-output, 300mA low-dropout (LDO) linear regulator with foldback current limit, active output discharge, and enable control in a 1mm × 1mm, 4-pin X2SON (DQN) package. It delivers 1% output accuracy, 460mV dropout at 300mA, 50µA quiescent current, and 65dB PSRR at 1kHz - optimized for battery-powered portable media players and streaming devices.

For engineers reviewing the TLV74028PDQNR datasheet, TLV74028PDQNR pinout, TLV74028PDQNR application, or TLV74028PDQNR equivalent, key selection criteria include its foldback overcurrent protection, thermal shutdown (158°C), UVLO operation, active pulldown resistance (120Ω), and compatibility with 1µF ceramic output capacitance for stability.

Technical Context

The TLV74028PDQNR implements a CMOS-based LDO architecture with an internal bandgap reference, hybrid brickwall-foldback current limiting (ICL = 360mA, ISC = 40mA), and undervoltage lockout (UVLO rising threshold = 1.25V, hysteresis = 0.05V). Its pass transistor operates in ohmic region during dropout, enabling regulation down to VIN = VOUT + 460mV at full load.

Functional modes include normal regulation (VIN ≥ VOUT + VDO, EN high), dropout tracking (VIN < VOUT + VDO), and disabled state with active output discharge (RPULLDOWN = 120Ω). Startup time is 100µs with 1µF COUT, and thermal shutdown resets at 140°C after cooling.

Key Specifications

Pinout & Package

TLV74028PDQNR uses the DQN package: 1mm × 1mm, 4-pin X2SON with exposed thermal pad electrically tied to GND. The pad must be soldered to a large PCB ground plane for thermal performance (RθJB = 164.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV74028PDQNR, TLV74128PDQNR removes active discharge but retains identical footprint and accuracy, while MCP1700T-2802E/TT trades current capability and protection features for extreme quiescent savings in non-sequenced applications.

Availability

TLV74028PDQNR is available at Aetrix Electronics and suitable for portable media players, streaming media players, and home printers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for volume production.

Supply support for TLV74028PDQNR 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 LDO design expertise and broad automotive, industrial, and consumer qualification.

The TLV740P family was engineered for space-constrained, battery-operated applications demanding low IQ, fast transient response, and robust fault protection - directly addressing design challenges in portable computing and multimedia endpoints.

FAQ

What is the minimum input voltage required for TLV74028PDQNR to regulate 2.8V output at 300mA?

The TLV74028PDQNR requires a minimum input voltage of 3.26V (2.8V + 460mV dropout) to maintain regulation at 300mA load. Below this, the device enters dropout mode and output voltage tracks VIN minus VDO. Operation down to 1.4V input is supported, but regulation is only guaranteed above the dropout threshold.

Does TLV74028PDQNR require an external pull-up resistor on the EN pin?

No, TLV74028PDQNR does not require an external pull-up on EN. Its enable pin has negligible leakage (10nA), so a direct connection to MCU GPIO is sufficient. If unused, TI recommends tying EN to IN - not floating - to ensure reliable enablement without added components.

How does the foldback current limit function in TLV74028PDQNR during a short-circuit event?

During a short, TLV74028PDQNR limits output current to 40mA (ISC) once VOUT drops below VFOLDBACK = 2.66V (0.95 × 2.8V). This foldback action reduces power dissipation versus constant-current limiting, lowering junction temperature rise and delaying thermal shutdown activation compared to brickwall-only schemes.

Can TLV74028PDQNR safely drive a 10µF ceramic output capacitor?

Yes, TLV74028PDQNR is stable with 1µF to 100µF ceramic output capacitors (COUT), per TI's Recommended Operating Conditions. A 10µF X7R capacitor improves load transient response and reduces output ripple, provided it is placed within 2mm of the OUT and GND pins.

What thermal performance can be expected from TLV74028PDQNR in a standard 2-layer PCB layout?

In a typical 2-layer board with 1-in² GND copper pour connected to the thermal pad, TLV74028PDQNR achieves RθJB ≈ 165°C/W. At 300mA and 3.5V input, power dissipation is ~210mW, resulting in ~35°C junction-to-ambient rise - well within the –40°C to 85°C operating range without forced airflow.