Texas Instruments LP2992ILDX-3.3

Overview

LP2992ILDX-3.3 from Texas Instruments is a fixed-output, micropower, ultra-low-dropout linear regulator delivering 3.3 V at up to 250 mA with ±0.5% output accuracy (new chip), 30 µV_RMS output noise (with 10 nF bypass capacitor), and 70 dB PSRR at 1 kHz - designed for noise-sensitive analog and low-voltage MCU power rails in battery-powered industrial systems.

For engineers reviewing the LP2992ILDX-3.3 datasheet, LP2992ILDX-3.3 pinout, LP2992ILDX-3.3 application, or LP2992ILDX-3.3 equivalent, this page delivers verified specifications, SOT-23-5 pin functions, thermal and transient performance data, and real-world substitution guidance - all grounded in TI's SNVS171L production datasheet (Feb 2025 revision).

Technical Context

The LP2992ILDX-3.3 employs a CMOS pass transistor architecture with internal bandgap reference and soft-start circuitry, enabling controlled inrush current and stable regulation down to 2.5 V input. Its BYPASS pin connects to an external 10 nF capacitor to reduce reference noise, directly enabling the 30 µV_RMS noise spec.

It integrates overcurrent limiting (300–350 mA peak), thermal shutdown, and active-high ON/OFF enable logic with 0.72 V low-threshold and 0.85 V high-threshold (new chip), supporting precise system-level power sequencing in motor control and RF subsystems.

Key Specifications

Pinout & Package

LP2992ILDX-3.3 is packaged in a 5-pin SOT-23 (DBV) case measuring 2.9 mm × 2.8 mm, with exposed pad not present (legacy DBV variant). Pin 1 is IN; Pin 2 is GND; Pin 3 is ON/OFF; Pin 4 is BYPASS; Pin 5 is OUT.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, 250 mA LDO applications.

Compared with TSS721AIDR, LP2992ILDX-3.3 delivers 30 µV_RMS noise via its dedicated BYPASS pin - critical for RF and precision analog - while TPS7A2033PDBVR offers lower noise and higher current but mandates PCB redesign due to 6-pin WSON packaging and distinct pinout.

Availability

LP2992ILDX-3.3 is available at Aetrix Electronics and suitable for industrial motor drives, active antenna systems, land mobile radios, and home appliance control boards requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for LP2992ILDX-3.3 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 power management ICs, with decades of expertise in high-reliability industrial and automotive power solutions.

The LP2992 belongs to TI's micropower LDO family engineered for ultra-low-noise, wide-input, and thermally robust operation in space-constrained industrial and RF applications - prioritizing noise suppression, dropout efficiency, and system-level protection.

FAQ

What is the minimum input voltage required for LP2992ILDX-3.3 to maintain regulation at full load and high temperature?

The LP2992ILDX-3.3 requires a minimum input voltage of 3.525 V (3.3 V + 225 mV dropout) at 250 mA and 25°C. At –40°C to +125°C junction temperature, the worst-case dropout rises to 340 mV, so VIN(MIN) = 3.64 V is required to sustain regulation across temperature and full load per TI's SNVS171L datasheet Section 5.5.

Can LP2992ILDX-3.3 operate without the BYPASS capacitor, and what impact does omitting it have?

Yes, LP2992ILDX-3.3 functions without the BYPASS capacitor, but output noise increases from 30 µV_RMS to approximately 120 µV_RMS (per Figure 5-23/5-24). The BYPASS pin is optional for basic regulation but mandatory to achieve the specified low-noise performance - especially in ADC reference, PLL, or RF bias applications.

What is the thermal resistance (RθJA) of the LP2992ILDX-3.3 in its SOT-23-5 package, and how does it affect power dissipation?

The LP2992ILDX-3.3 in the DBV (SOT-23-5) package has RθJA = 178.6°C/W (new chip, JEDEC 2s2p board). At 250 mA load with 5 V input, power dissipation is (5 V – 3.3 V) × 0.25 A = 0.425 W, resulting in ~76°C junction rise above ambient - well within the 125°C max TJ limit when ambient stays below 49°C. Layout with copper pour improves thermal performance.

Does LP2992ILDX-3.3 support reverse current protection, and how is output disconnection handled during shutdown?

LP2992ILDX-3.3 does not include reverse current protection. However, when disabled via the ON/OFF pin, it activates an internal output pulldown circuit that actively discharges the OUT pin through GND - preventing floating outputs and ensuring clean power-down sequencing in multi-rail systems without external bleed resistors.

Is LP2992ILDX-3.3 compatible with ceramic output capacitors under 2.2 µF, and what is the minimum stable value?

TI specifies a minimum 2.2 µF ceramic output capacitor for stability across all operating conditions. While 1 µF may work in some cases (per Section 5.3), derating to 50% means effective capacitance must remain ≥1 µF at bias - so 2.2 µF is the validated minimum. Using smaller values risks instability, especially under load transients or temperature extremes.