Texas Instruments LP2985AIM5X-2.5

Overview

LP2985AIM5X-2.5 from Texas Instruments is a micropower, ultra-low-dropout linear regulator in SOT-23-5 package delivering 150 mA output current with 2.5 V fixed output voltage, 1% accuracy (A-grade), 300 mV typical dropout at full load, and 30 µV_RMS output noise (300 Hz–50 kHz) when using a 10 nF bypass capacitor - designed for battery-powered portable electronics requiring low quiescent current and high PSRR.

For engineers reviewing the LP2985AIM5X-2.5 datasheet, LP2985AIM5X-2.5 pinout, LP2985AIM5X-2.5 application, or LP2985AIM5X-2.5 equivalent, key selection considerations include its 75 µA quiescent current at 1 mA load, ON/OFF logic control interface, stability with 5 mΩ ESR ceramic capacitors, and thermal shutdown/overcurrent protection - critical for space-constrained, low-noise power rails in handheld devices.

Technical Context

The LP2985AIM5X-2.5 uses a vertically integrated PNP (VIP) process to achieve ultra-low dropout (280–575 mV at 150 mA across temperature) and low ground current (850 µA typical at 150 mA). Its internal reference and feedback loop ensure 1% output voltage accuracy over –40°C to 125°C junction temperature and line/load regulation of ±0.014%/V.

It features an active ON/OFF control pin (logic-high enable, <0.15 V disable threshold), dedicated BYPASS pin for noise reduction, and foldback current limiting that caps short-circuit current at 400 mA while enabling 350 mA peak output under nominal conditions - all within a thermally optimized SOT-23-5 package with R_θJA = 169.0°C/W.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90 mm × 1.60 mm body, 0.95 mm height, gull-wing leads; rated for –40°C to 125°C junction temperature and 169.0°C/W junction-to-ambient thermal resistance on standard PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2985AIM5X-2.5, TCS2117-2.5 trades noise performance for marginally lower dropout, while MCP1700T-2502E/MB sacrifices enable functionality and low-noise capability for higher output current and lower unit cost - making LP2985AIM5X-2.5 optimal for battery-powered systems demanding simultaneous low noise, precise enable control, and ultra-low dropout.

Availability

LP2985AIM5X-2.5 is available at Aetrix Electronics and suitable for cellular phones, Bluetooth audio modules, portable medical sensors, and industrial handheld scanners requiring stable component supply, long-lifecycle support, and guaranteed parametric compliance.

Supply support for LP2985AIM5X-2.5 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 connectivity technologies, with decades of expertise in power management IC design and manufacturing.

The LP2985-N product line was engineered specifically for micropower, ultra-low-noise, ultra-low-dropout regulation in space-constrained portable electronics - emphasizing battery longevity, signal integrity, and robustness across wide temperature and load ranges.

FAQ

What is the minimum input voltage required for LP2985AIM5X-2.5 to regulate 2.5 V output?

The LP2985AIM5X-2.5 requires a minimum input voltage of 3.1 V under recommended operating conditions - defined as the greater of 3.1 V or V_OUT(MAX) + rated dropout voltage (575 mV max at 150 mA and full temperature range). Below this, regulation is not guaranteed and output voltage will track input.

Can LP2985AIM5X-2.5 operate without the BYPASS capacitor?

Yes, LP2985AIM5X-2.5 functions normally without the BYPASS capacitor, delivering 2.5 V output with standard LDO performance. However, omitting the 10 nF ceramic capacitor between BYPASS and GND increases output noise from 30 µV_RMS to approximately 100 µV_RMS, which may impact noise-sensitive analog circuits.

What output capacitor value and type are required for stable operation of LP2985AIM5X-2.5?

LP2985AIM5X-2.5 requires a minimum 2.2 µF ceramic output capacitor with ESR ≤5 mΩ for guaranteed stability across 1 mA–150 mA load and –40°C to 125°C. Larger values (e.g., 4.7 µF or 10 µF) improve transient response and PSRR without compromising stability.

How does the ON/OFF pin of LP2985AIM5X-2.5 behave during power-up?

During power-up, the LP2985AIM5X-2.5 remains disabled until the ON/OFF pin voltage exceeds 1.6 V (min) across temperature. If left floating or weakly pulled, unpredictable startup may occur; TI recommends actively terminating ON/OFF to VIN via a resistor or direct connection if enable control is unused.

Is LP2985AIM5X-2.5 compatible with ceramic input capacitors?

Yes, LP2985AIM5X-2.5 is fully compatible with ceramic input capacitors. A minimum 1 µF X5R or X7R ceramic capacitor placed ≤1 cm from the IN pin to GND is required for stability and EMI suppression; no ESR requirement applies, but capacitance must remain ≥1 µF over temperature and bias.