Texas Instruments TLV71728PDQNR

Overview

TLV71728PDQNR from Texas Instruments is a 150-mA, low-dropout linear regulator with 2.8 V fixed output, 215 mV dropout at full load, 0.5% typical accuracy, 35 µA quiescent current, and active pulldown for rapid output discharge. It serves as a power supply rail generator in battery-powered portable electronics requiring stable low-noise voltage regulation.

For engineers reviewing the TLV71728PDQNR datasheet, TLV71728PDQNR pinout, TLV71728PDQNR application, or TLV71728PDQNR equivalent, key selection criteria include foldback current limiting (40 mA short-circuit limit), stability with ≥0.1 µF ceramic output capacitance, 70 dB PSRR at 1 kHz, UVLO threshold of 1.6 V, and operation across –40°C to +85°C junction temperature.

Technical Context

The TLV71728PDQNR employs a PMOS pass transistor architecture enabling ultra-low dropout and inherent reverse-voltage protection via its body diode. Its internal foldback current limit initiates near 350 mA and reduces output current as VOUT collapses, limiting short-circuit dissipation to ~16 mW at 40 mA.

It integrates an active high-enable logic interface (EN > 0.9 V to enable), undervoltage lockout (UVLO rising = 1.6 V), and a dedicated 120 Ω pulldown resistor on OUT to discharge loads during shutdown - all within a thermally enhanced 1-mm × 1-mm X2SON (DQN) package with exposed thermal pad.

Key Specifications

Pinout & Package

TLV71728PDQNR is housed in a 4-pin, 1.0 mm × 1.0 mm X2SON (DQN) package with wettable flank leads and an exposed thermal pad connected to GND for enhanced thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLS850F28T and AP7361C-28YG-13, TLV71728PDQNR uniquely combines ultra-small X2SON packaging, active pulldown, foldback current limiting, and sub-220 mV dropout - making it optimal for space- and power-constrained portable designs where rapid discharge and fault resilience are mandatory.

Availability

TLV71728PDQNR is available at Aetrix Electronics and suitable for smartphone power management, wearable sensor hubs, industrial handheld terminals, and medical point-of-care devices requiring stable component supply with guaranteed long-term sourcing.

Supply support for TLV71728PDQNR 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 and embedded processing technologies, with leadership in power management ICs and precision analog solutions.

The TLV717P series was designed specifically for portable, battery-powered applications demanding ultra-low quiescent current, small form factor, and robust fault protection - targeting smartphones, wearables, and IoT edge nodes.

FAQ

What is the minimum input voltage required for TLV71728PDQNR to maintain regulation?

The TLV71728PDQNR requires VIN ≥ VOUT + VDO = 2.8 V + 0.215 V = 3.015 V at 150 mA load to remain in regulation. Below this, it enters dropout mode where VOUT = VIN − VDO. The device also enforces UVLO - regulation does not initiate until VIN rises above 1.6 V, regardless of EN state. This ensures clean startup and prevents erratic behavior during brownout conditions.

Does TLV71728PDQNR require an input capacitor for stability?

No, TLV71728PDQNR does not require an input capacitor for stability, but TI strongly recommends a 0.1–1 µF low-ESR ceramic capacitor between IN and GND. This capacitor mitigates voltage spikes caused by source impedance during load transients and improves PSRR and noise rejection. Without it, inductive traces or high-impedance supplies may induce oscillation or overshoot, especially in compact layouts with fast-switching loads.

How does the foldback current limit function in TLV71728PDQNR during a short circuit?

During a short circuit, TLV71728PDQNR's foldback current limit reduces output current from ~350 mA (initiation point) down to ~40 mA (typical short-circuit current). Unlike fixed-current limiters, this behavior lowers power dissipation in the PMOS pass element - (VIN − VOUT) × ILIMIT drops significantly as VOUT collapses. This prevents thermal runaway and allows indefinite short-circuit operation without triggering thermal shutdown, enhancing system safety.

Can TLV71728PDQNR operate without an enable signal connected?

Yes - TLV71728PDQNR can operate without an external enable signal by connecting EN directly to IN. Since the enable threshold is 0.9 V (min), and VIN operates from 1.7 V to 5.5 V, this connection guarantees the device remains enabled whenever input power is present. However, this forfeits shutdown capability and active pulldown functionality, so it should only be used in always-on applications where output discharge is not required.

What is the purpose of the thermal pad on the TLV71728PDQNR DQN package?

The exposed thermal pad on the TLV71728PDQNR's X2SON (DQN) package must be soldered to a PCB GND plane to achieve specified thermal performance. It reduces junction-to-board thermal resistance (R_θJB = 330°C/W) and lowers steady-state die temperature under load. Omitting thermal pad connection degrades R_θJA from 393.3°C/W to >500°C/W, risking thermal shutdown at ≤100 mA - especially critical in sealed enclosures or high ambient temperature environments.