Texas Instruments TLV71721PDQNR

Overview

TLV71721PDQNR from Texas Instruments is a 150-mA, low-dropout linear regulator with 2.1-V fixed output voltage, 215-mV dropout at full load, 0.5% typical DC accuracy, and active pulldown for rapid output discharge. It delivers stable regulation in portable electronics where ultra-low quiescent current (35 µA) and foldback current limiting (40 mA short-circuit limit) are critical for battery life and fault protection.

For engineers reviewing the TLV71721PDQNR datasheet, TLV71721PDQNR pinout, TLV71721PDQNR application, or TLV71721PDQNR equivalent, key selection considerations include its 1-mm × 1-mm X2SON (DQN) package, 0.1-µF minimum stable output capacitance, 70-dB PSRR at 1 kHz, UVLO threshold of 1.6 V, and enable logic compatible with low-voltage GPIOs (EN high = >0.9 V).

Technical Context

The TLV71721PDQNR employs a PMOS pass transistor architecture enabling very low dropout and inherent reverse-current blocking via its integrated body diode. Its foldback current limit initiates near 350 mA and reduces output current as VOUT collapses, limiting power dissipation during shorts to ~16 mW (40 mA × 0.4 V).

It integrates undervoltage lockout (1.6 V rising threshold), active pulldown (120-Ω internal resistor), and operates across –40°C to +85°C junction temperature. Stability is guaranteed with ≥0.1 µF effective ceramic output capacitance, supporting compact, cost-effective bias-voltage-tolerant capacitors without ESR constraints.

Key Specifications

Pinout & Package

TLV71721PDQNR is housed in a 4-pin, 1.00 mm × 1.00 mm X2SON (DQN) package with 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 TLS850F21TAV50 and MCP1702T-2102E/MB, TLV71721PDQNR offers the smallest footprint (1 mm²), lowest dropout (215 mV), and integrated active pulldown-making it optimal for space- and noise-constrained portable designs where rapid output discharge and extended battery runtime are essential.

Availability

TLV71721PDQNR is available at Aetrix Electronics and suitable for smartphone RF front-ends, wearable sensor hubs, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TLV71721PDQNR 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, precision amplifiers, and high-reliability signal chain solutions.

The TLV717P series was designed specifically for portable and battery-powered applications demanding ultra-low quiescent current, small size, and robust fault protection-including foldback current limiting and active output discharge.

FAQ

What is the minimum input voltage required for TLV71721PDQNR to regulate at 2.1 V?

The TLV71721PDQNR requires a minimum input voltage of 2.315 V to maintain regulation at 2.1 V under full 150-mA load, based on its 215-mV dropout specification. At lighter loads, dropout decreases-enabling operation from as low as 2.15 V. Input voltage must also exceed the 1.6-V UVLO threshold to enable startup.

Does TLV71721PDQNR require an input capacitor for stability?

No, TLV71721PDQNR does not require an input capacitor for stability. However, a 0.1-µF to 1-µF low-ESR ceramic capacitor between IN and GND is strongly recommended to improve transient response, suppress source impedance effects, and enhance noise and ripple rejection-especially when the device is remote from the power source or subjected to fast load transients.

Can TLV71721PDQNR be used with non-ceramic output capacitors?

Yes, TLV71721PDQNR can be used with non-ceramic capacitors such as tantalum or polymer, provided the effective capacitance at operating bias voltage and temperature remains ≥0.1 µF. Ceramic X5R/X7R types are preferred due to minimal value and ESR drift over temperature and voltage; other dielectrics must be derated accordingly to ensure stability.

What is the purpose of the active pulldown feature in TLV71721PDQNR?

The active pulldown feature in TLV71721PDQNR uses a 120-Ω internal resistor to rapidly discharge the output node when the EN pin is pulled low. This prevents floating voltages that could cause unintended behavior in downstream logic, eliminates residual charge during power sequencing, and ensures clean, predictable resets-critical in systems with multiple power domains or strict low-power states.

How does the foldback current limit function in TLV71721PDQNR during a short-circuit event?

During a short-circuit, TLV71721PDQNR's foldback current limit reduces output current as VOUT collapses-initiating near 350 mA and settling at ~40 mA when VOUT ≈ 0 V. This limits power dissipation in the PMOS pass element to ~16 mW, preventing thermal shutdown and enabling safe, sustained fault operation without external protection components.