onsemi LP2951ACN-3.0G

Overview

LP2951ACN-3.0G from onsemi is a micropower, low-dropout linear voltage regulator with fixed 3.0 V ±0.5% output, 100 mA load capability, 75 µA quiescent current, and integrated error flag and logic-level shutdown. It operates from 4.0 V to 30 V input and is used in battery-powered instrumentation, portable medical devices, and industrial sensor nodes requiring stable low-power regulation.

For engineers reviewing the LP2951ACN-3.0G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 100 mA (≤450 mV), output voltage tolerance (±0.5% at 25°C), thermal shutdown behavior, error comparator threshold accuracy (±5% of V_OUT), and SOIC-8 package compatibility with standard reflow profiles.

Technical Context

The LP2951ACN-3.0G implements a PNP pass transistor architecture with internal 1.235 V bandgap reference, error amplifier, and open-collector error comparator. Its feedback path is internally configured for 3.0 V via precision resistor divider, eliminating external components for fixed-output use.

Shutdown control is TTL/CMOS-compatible (logic "1" ≥2.0 V disables output), and the error output asserts low when V_OUT drops >5% below nominal-e.g., below 2.85 V for this 3.0 V variant-enabling reliable power-on reset or brownout detection without external circuitry.

Key Specifications

Pinout & Package

LP2951ACN-3.0G is housed in an 8-pin SOIC package (Case 751) with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012 compliance. The package supports standard IR reflow and offers 180°C/W junction-to-ambient thermal resistance with minimal PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with LP2951CD-3.0R2G, the LP2951ACN-3.0G delivers tighter output accuracy for precision analog subsystems; versus NCV2951ACDR2G, it lacks AEC-Q100 qualification but offers lower unit cost for industrial and consumer applications.

Availability

LP2951ACN-3.0G is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical devices, and industrial sensor nodes requiring stable component supply with guaranteed long-term availability.

Supply support for LP2951ACN-3.0G 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

onsemi is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The LP2951 family is designed for micropower, low-dropout regulation in space- and energy-constrained systems, emphasizing ultra-low quiescent current, high accuracy, and integrated supervision features like error flag and shutdown.

FAQ

What is the maximum input voltage rating for the LP2951ACN-3.0G?

The LP2951ACN-3.0G has an absolute maximum input voltage rating of 30 V DC, with a peak transient rating of 32 V for durations under 300 ms. Exceeding these limits risks permanent damage. For automotive applications with load dump transients, ensure external clamping or filtering keeps Vin within specification during fault conditions. The LP2951ACN-3.0G itself does not include integrated transient protection.

Does the LP2951ACN-3.0G require an external output capacitor, and what type is recommended?

Yes, the LP2951ACN-3.0G requires a minimum 1.0 µF ceramic output capacitor connected between Pin 1 (Output) and Pin 4 (Ground) for stability. X7R or X5R multilayer ceramic capacitors are recommended due to low ESR and stable capacitance over temperature and bias. Tantalum or aluminum electrolytic capacitors may be used if ESR is ≥1 Ω, but ceramics provide superior transient response and reliability in compact layouts.

How does the error output function on the LP2951ACN-3.0G, and what external components are needed?

The error output (Pin 5) on the LP2951ACN-3.0G is an open-collector comparator that pulls low when V_OUT drops more than 5% below nominal (i.e., ≤2.85 V). It requires an external pull-up resistor-typically 100 kΩ to 1 MΩ-to either V_OUT or another system rail. Pulling up to V_OUT prevents invalid high state during power-down. The LP2951ACN-3.0G sinks up to 400 µA in the active state, sufficient to drive most logic inputs directly.

Can the LP2951ACN-3.0G be used in adjustable-output configurations?

No-the LP2951ACN-3.0G is factory-configured for fixed 3.0 V output using internal resistor divider connections. While the LP2951 family supports adjustable operation via Pins 6 (VO Tap) and 7 (Feedback), the ACN-3.0G variant's internal routing locks the output to 3.0 V. For programmable output, select LP2951ACDR2G or LP2951ACDMR2G and use external resistors per the datasheet equation V_OUT = 1.235 V × (1 + R1/R2).

What is the thermal performance of the LP2951ACN-3.0G in its SOIC-8 package?

In the SOIC-8 (Case 751) package, the LP2951ACN-3.0G has a junction-to-ambient thermal resistance (R_JA) of 180°C/W under standard JEDEC test conditions. With 1 in² of 2-oz copper on the PCB, practical R_JA improves to ~70°C/W. At 100 mA load and 30 V input, worst-case power dissipation is ~2.7 W, requiring careful thermal design. Derate output current above 85°C ambient to avoid exceeding the 150°C maximum junction temperature.