company blog about Mingjiada Electronics Supply LP2981A-33 High-Precision Low-Dropout (LDO) Voltage Regulators, Suitable for Smart Meters and Portable Devices

Mingjiada Electronics supplies the LP2981A-33—a 100mA low-dropout regulator in SOT-23 packaging—in large quantities

LP2981A-33 Product Overview

Shenzhen Mingjiada Electronics Co., Ltd. (hereinafter referred to as ‘Mingjiada’), established in 1996, is a globally leading authorised independent distributor of electronic components, certified to the ISO 9001 Quality Management System and ISO 14001 Environmental Management System standards. With nearly three decades of industry experience and a stock of over 2 million part numbers, Mingjiada Electronics provides a comprehensive range of components and one-stop supply chain solutions for sectors including 5G communications, automotive electronics, industrial automation, the Internet of Things (IoT), artificial intelligence (AI) and consumer electronics.

Mingjiada Electronics currently stocks large quantities of the Texas Instruments LP2981A-33 low-dropout regulator (LDO), which features a compact SOT-23-5 package, a fixed output of 3.3V, and can deliver a continuous load current of up to 100mA. With its ultra-low dropout voltage, low quiescent current, high-precision output and comprehensive protection features, this device is an ideal choice for power management solutions in a wide range of portable and non-portable electronic devices.

Ordering information: LP2981A-33DBVR (taped and reeled, 3,000 pcs/reel)

Specifications

The main technical specifications of the LP2981A-33 are as follows:

Output type: Fixed 3.3 V

Output current Continuous load: 100 mA

Input voltage range Old chip: 2.2 to 16 V

Input voltage range New chip: 2.5 to 16 V

Output voltage accuracy (Class A): ±0.75 %

Voltage Drop (Typical): @100 mA 200 mV

Voltage Drop (Typical): @1 mA 7 mV

Quiescent Current (Typical): @100 mA 600 µA

Shut-down Current (Typical): ON/OFF pin pulled low 0.01 µA

Power Supply Rejection Ratio (PSRR): @1 kHz 63 dB

Noise: 160 µVrms

Operating Temperature Range (Junction Temperature): -40 to +125 °C

Package: SOT-23 5-pin

Package Dimensions: 2.90 × 1.60 mm

Key Features

1. Ultra-Low Dropout

The LP2981A-33 utilises a PNP transistor architecture, delivering a typical dropout voltage of just 200 mV at a full load of 100 mA, and as low as 7 mV at a light load of 1 mA. This characteristic enables it to maintain a stable output even when the difference between the input and output voltages is extremely small, significantly improving power conversion efficiency and making it particularly suitable for battery-powered devices.

2. Low Quiescent Current and Shut-down Function

The device utilises a vertical PNP process, resulting in a quiescent current significantly lower than that of conventional lateral PNP regulators. The typical quiescent current is 600 µA at a full load of 100 mA. When the ON/OFF pin is pulled low, the regulator enters shut-down mode, consuming as little as 0.01 µA (typical), thereby greatly extending battery standby time.

3. High-Precision Output

Class A devices feature an output voltage tolerance of ±0.75 per cent, ensuring high precision and stability for the 3.3 V output. This level of precision meets the stringent supply voltage requirements of low-voltage microcontrollers (MCUs) and processors.

4. Comprehensive Protection Mechanisms

Overcurrent protection: An internal current-limiting circuit prevents damage to the device caused by high load currents, faults or short-circuit events.

Over-temperature protection: Over-temperature shutdown protection prevents damage to the chip due to excessive temperature.

ESD protection: Exceeds the JESD 22 standard, with Human Body Model (HBM) protection up to 2000 V and Machine Model (MM) protection up to 200 V.

5. Fast Transient Response

The device offers fast transient response to changes in supply voltage and load, ensuring output voltage stability under dynamic load conditions.

6. Compact SOT-23 Package

Featuring a 5-pin SOT-23 (DBV) package measuring just 2.90 mm × 1.60 mm, it is ideally suited for portable device designs with limited PCB space.

Typical Applications

The LP2981A-33 is widely used in the following areas:

Smart meters: In battery-powered environments, the ultra-low quiescent current and shutdown function effectively extend battery life

Servo and motor control: Single-axis and multi-axis servo drives

Mobile phones and cameras: Provides a stable 3.3V power supply for baseband processors, image sensors and similar components

Audio and portable speakers: Low-noise output ensures pure sound quality

Telecommunications and networking equipment: Provides a reliable power supply for communication modules

Laptops and PDAs: Peripheral power management

Server power supplies: 12V auxiliary power supply

Residential circuit breakers: Industrial control applications

Furthermore, the LP2981A-33 is also suitable for wearable products such as smartwatches and health monitoring devices, which typically rely on small batteries for power; the LP2981A-33 provides a stable 3.3V output to ensure the devices function correctly.

Typical Application Circuit

The typical application circuit for the LP2981A-33 is very straightforward:

Input Capacitor (CIN): It is recommended to use a capacitor of at least 1 µF at the input (to cover the entire operating temperature range)

Output capacitor (COUT): As a PNP regulator, the LP2981A-33 requires the output capacitor to meet both minimum capacitance and ESR requirements

ON/OFF pin: Must be actively terminated; pulling it low enters shutdown mode

NC pin (Pin 4): Must be left floating; must not be connected

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Why choose Mingjiada Electronics?

Guarantee of genuine products: Mingjiada Electronics specialises in supplying genuine electronic components; all products are traceable

Extensive stock: Over 2 million stock items, covering obscure, scarce and discontinued components

Fast delivery: Thanks to a comprehensive supply chain system and intelligent warehousing, we ensure rapid dispatch

Full product range: Our product range covers everything from high-end chips to basic components

Mingjiada Electronics currently has a large stock of LP2981A-33 / LP2981A-33DBVR. We welcome enquiries from both new and existing customers regarding procurement!

Contact Us

Please visit the Mingjiada Electronics website (www.integrated-ic.com) for further product information and the latest quotations. Mingjiada Electronics – your trusted one-stop partner for electronic component procurement!

Tags: LP2981A-33DBVR, LP2981A-33DBV, LP2981A-33DB, LP2981A-33D, LP2981A-33