Texas Instruments LP2985AIM5-3.2/NOPB

Overview

LP2985AIM5-3.2/NOPB from Texas Instruments is a micropower, ultra-low-dropout linear regulator delivering 150 mA output current with 3.2 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 stable low-noise supply rails.

For engineers reviewing the LP2985AIM5-3.2/NOPB datasheet, LP2985AIM5-3.2/NOPB pinout, LP2985AIM5-3.2/NOPB application, or LP2985AIM5-3.2/NOPB equivalent, key selection considerations include its SOT-23-5 package, ON/OFF logic control interface, compatibility with low-ESR ceramic capacitors (≥2.2 µF), <1 µA shutdown quiescent current, and thermal/overcurrent protection - all critical for space-constrained, energy-sensitive designs.

Technical Context

The LP2985AIM5-3.2/NOPB uses a vertically integrated PNP (VIP) process to achieve ultra-low dropout (280–575 mV at 150 mA over temperature) and low ground current (75 µA at 1 mA, 850 µA at 150 mA). Its internal reference and feedback loop ensure 1% output voltage accuracy across –40°C to 125°C junction temperature.

It integrates an active ON/OFF control input (logic-high enable, <0.15 V disable threshold), a dedicated BYPASS pin for noise reduction via external 10-nF capacitor, and foldback current limiting with thermal shutdown - enabling robust operation in transient-load and fault conditions without external circuitry.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90 mm × 1.60 mm body, 0.95 mm height, gull-wing leads - optimized for high-density PCB layouts in handheld and wearable devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2985AIM5-3.2/NOPB, TLS820B0LDV50 provides automotive reliability but mismatches voltage and adds complexity, while MCP1700-3302E/TO offers lower quiescent current but sacrifices noise performance, enable control, and SOT-23 compactness - making LP2985AIM5-3.2/NOPB optimal for portable 3.2 V systems demanding precision, low noise, and dynamic power control.

Availability

LP2985AIM5-3.2/NOPB is available at Aetrix Electronics and suitable for cellular phones, portable medical sensors, industrial handheld terminals, and IoT edge nodes requiring stable component supply with consistent parametric performance and long-term lifecycle support.

Supply support for LP2985AIM5-3.2/NOPB 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 battery-powered portable electronics, emphasizing ultra-low dropout, micropower operation, low noise, and ceramic-capacitor compatibility to simplify design and extend runtime.

FAQ

What is the minimum input voltage required for LP2985AIM5-3.2/NOPB to regulate 3.2 V at 150 mA?

The LP2985AIM5-3.2/NOPB requires a minimum input voltage of 3.48 V (3.2 V + 280 mV typical dropout) to maintain regulation at 150 mA load. Over temperature, the maximum dropout rises to 575 mV, so 3.775 V input ensures regulation across –40°C to 125°C junction range. The recommended minimum VIN is 3.1 V per datasheet, but that applies only at lighter loads.

Can LP2985AIM5-3.2/NOPB operate with a 1-µF output capacitor?

No - LP2985AIM5-3.2/NOPB requires a minimum 2.2 µF ceramic output capacitor for stability, as specified in the datasheet. Using 1 µF risks oscillation or poor transient response due to insufficient phase margin. The device is optimized for ≥2.2 µF with ESR ≤50 mΩ; increasing capacitance improves load-step immunity without penalty.

How does the BYPASS pin on LP2985AIM5-3.2/NOPB reduce output noise?

The BYPASS pin connects to an internal low-noise reference buffer; adding a 10-nF ceramic capacitor between BYPASS and GND shunts high-frequency reference noise, lowering total output noise from ~120 µV_RMS to 30 µV_RMS (300 Hz–50 kHz). Omitting this capacitor degrades noise performance but does not affect regulation or stability.

Is LP2985AIM5-3.2/NOPB compatible with tantalum output capacitors?

While the LP2985AIM5-3.2/NOPB can technically operate with tantalum capacitors, it is explicitly designed and characterized for ceramic capacitors with ESR as low as 5 mΩ. Tantalum caps introduce higher ESR and potential surge-current failure modes; TI recommends ceramic (X5R/X7R) for guaranteed stability, size efficiency, and reliability - especially in portable applications.

What happens to LP2985AIM5-3.2/NOPB when the ON/OFF pin is left floating?

The ON/OFF pin has no internal pull-up or pull-down; if left floating, its voltage is undefined and may drift into the indeterminate region (0.15–1.6 V), causing erratic enable/disable behavior or partial conduction. The datasheet mandates active termination - tie to VIN via resistor or direct connection if always-on operation is intended, or drive with clean logic signal for controlled shutdown.