Texas Instruments LP2985IM5X-5.7/NOPB

Overview

LP2985IM5X-5.7/NOPB from Texas Instruments is a micropower, ultra-low-dropout linear regulator delivering 150 mA output current with 5.7 V fixed output voltage, 300 mV typical dropout at full load, 1% output accuracy (A-grade), and 30 µV_RMS output noise (with 10 nF bypass capacitor). It serves as a precision, low-noise power supply for battery-powered portable electronics requiring stable voltage under light-to-moderate loads.

For engineers reviewing the LP2985IM5X-5.7/NOPB datasheet, LP2985IM5X-5.7/NOPB pinout, LP2985IM5X-5.7/NOPB application, or LP2985IM5X-5.7/NOPB equivalent, key selection considerations include its SOT-23-5 package footprint, ON/OFF logic control interface, ceramic-capacitor stability down to 5 mΩ ESR, shutdown quiescent current < 0.01 µA, and thermal/overcurrent protection for robust operation in space-constrained embedded systems.

Technical Context

The LP2985IM5X-5.7/NOPB uses a vertically integrated PNP (VIP) process to achieve ultra-low dropout (280–575 mV at 150 mA across 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 tolerance over –40°C to 125°C junction temperature.

It integrates an active ON/OFF control input (logic-high enable, <0.15 V disable threshold), BYPASS pin for noise filtering via external 10 nF capacitor, and foldback current limiting with thermal shutdown. Stability is guaranteed with ≥2.2 µF ceramic output capacitors having ESR as low as 5 mΩ - eliminating need for tantalum or electrolytic types.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90 mm × 1.60 mm body size, surface-mount, thermally enhanced plastic case with exposed pad not present (standard DBV).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, 5 V–6 V LDO applications.

Compared with LP2985IM5X-5.7/NOPB, MCP1703T-5002E/MB offers higher current but sacrifices 5.7 V precision and noise performance, while TPS7A2057PDBVR delivers superior noise and dropout but removes integrated ON/OFF control - increasing design complexity for power-gated systems.

Availability

LP2985IM5X-5.7/NOPB is available at Aetrix Electronics and suitable for cellular modems, portable medical sensors, industrial handheld terminals, and smart camera modules requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.

Supply support for LP2985IM5X-5.7/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 ICs for industrial, automotive, and consumer markets.

The LP2985-N product line was designed specifically for micropower, ultra-low-noise, ultra-low-dropout regulation in space-constrained, battery-powered portable electronics - emphasizing ceramic-capacitor compatibility, sub-µA shutdown, and high accuracy across temperature.

FAQ

What is the minimum input voltage required for LP2985IM5X-5.7/NOPB to regulate 5.7 V output?

The LP2985IM5X-5.7/NOPB requires a minimum input voltage of 5.98 V (5.7 V + 280 mV typical dropout) to maintain regulation at 150 mA load. At lighter loads, dropout drops to 7 mV (1 mA), allowing operation from as low as 5.707 V. The datasheet specifies 3.1 V minimum VIN only for higher-output-voltage variants; for LP2985IM5X-5.7/NOPB, the practical lower limit is defined by dropout plus VOUT.

Can LP2985IM5X-5.7/NOPB operate without the BYPASS capacitor?

Yes, LP2985IM5X-5.7/NOPB functions normally without the BYPASS capacitor, delivering 5.7 V output with standard specifications. However, omitting the 10 nF capacitor increases output noise from 30 µV_RMS to approximately 75 µV_RMS. The BYPASS pin is optional - it enhances noise performance but is not required for basic regulation or stability.

Is LP2985IM5X-5.7/NOPB compatible with 2.2 µF X5R ceramic capacitors on the output?

Yes, LP2985IM5X-5.7/NOPB is explicitly characterized and guaranteed stable with 2.2 µF ceramic output capacitors having ESR as low as 5 mΩ - matching typical X5R dielectric behavior. The device's internal compensation eliminates need for ESR-based stabilization, making X5R, X7R, and other low-ESR ceramics fully suitable without derating or parallel combinations.

What happens to LP2985IM5X-5.7/NOPB when the ON/OFF pin is left floating?

Leaving the ON/OFF pin floating on LP2985IM5X-5.7/NOPB risks undefined operation due to lack of internal pull-up/down. The datasheet mandates active termination: tie to VIN for always-on operation or drive with a clean logic signal. Floating may cause erratic enable/disable behavior, increased ground current, or failure to start - always connect ON/OFF to a defined voltage per Section 7.4.2.

Does LP2985IM5X-5.7/NOPB support reverse input-output voltage conditions?

No, LP2985IM5X-5.7/NOPB does not support reverse input-output voltage. The internal PNP pass transistor includes a parasitic diode from IN to OUT. If V_OUT > V_IN, this diode becomes forward-biased, causing uncontrolled current flow, potential overheating, and possible device damage. Input voltage must always be ≥ output voltage during operation and startup.