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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics LK112M25TR

Name: LK112M25TR
Brand: STMicroelectronics
SKU: LK112M25TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LK112M25TR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: SC-74A, SOT-753

Datasheet:: LK112M25TR.pdf

Description:: IC REG LINEAR 2.5V 150MA SOT23-5

Quantity:: RFQ Add To RFQ list

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Inventory:1,679

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Product details

Overview

LK112M25TR from STMicroelectronics is a 2.5 V fixed-output, low-noise, low-dropout linear voltage regulator with integrated shutdown control and internal PNP pass transistor. It delivers up to 150 mA output current, maintains 350 mV dropout at full load, draws only 250 µA quiescent current in ON mode and <0.1 µA in OFF mode, and achieves 30 µV_rms output noise (10 Hz–80 kHz) with 0.1 µF bypass capacitor - ideal for powering precision analog sensors and RF front-ends in battery-operated IoT nodes.

For engineers reviewing the LK112M25TR datasheet, LK112M25TR pinout, LK112M25TR application, or LK112M25TR equivalent, key selection criteria include its 2.5 V fixed output, SOT23-5L package footprint, TTL/CMOS-compatible SHDN pin, thermal/current protection, and ultra-low noise performance under light-to-moderate loads.

Technical Context

The LK112M25TR implements a PNP-based LDO architecture enabling low dropout (290 mV typ. at 150 mA) while maintaining stability with minimal external capacitance (2.2 µF output, 1 µF input). Its shutdown circuit accepts logic-level control (ON ≥1.8 V, OFF ≤0.6 V), reducing quiescent current to sub-100 nA in disable state.

Noise performance is actively managed via a dedicated Bypass pin accepting a 0.1 µF capacitor to suppress internal reference and error amplifier noise, achieving 30 µV_rms across 10 Hz–80 kHz bandwidth. Internal current limiting and thermal shutdown (trip at ~150 °C) provide fault resilience without external components.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.5 V ±2 % - stable reference-grade supply for ADCs, op-amps, and RF ICs without external feedback.
Max Output Current	150 mA - sufficient for microcontroller cores, sensor signal chains, and low-power wireless transceivers.
Dropout Voltage	290 mV typ. at 150 mA - enables operation from 2.79 V input, supporting single-cell Li-ion or two-cell alkaline systems.
Quiescent Current	250 µA max. in ON mode; 0.1 µA in OFF mode - extends battery life in sleep-wake cycling applications.
Output Noise	30 µV_rms (10 Hz–80 kHz, 0.1 µF bypass) - meets stringent noise requirements of precision instrumentation and GHz-band RF receivers.
Line Regulation	0.7–20 mV over VIN = VOUT+1 V to VOUT+6 V - ensures stable output despite battery voltage sag or supply ripple.
Thermal Shutdown	Activates at ~150 °C junction temperature - protects device and PCB during overload or poor heatsinking.

Pinout & Package

Supplied in compact SOT23-5L package (2.95 mm × 1.60 mm × 1.30 mm), optimized for space-constrained portable designs and offering R_thJA = 255 °C/W for passive thermal management.

Pin/Terminal	Circuit Role	Design Meaning
1 - SHDN	Logic-controlled enable input	Active-high TTL/CMOS-compatible shutdown pin; ≥1.8 V enables regulation, ≤0.6 V disables output and reduces I_q to <0.1 µA.
2 - GND	Power and thermal reference	Internally connected to die attach flag to minimize thermal resistance and improve power dissipation capability.
3 - Bypass	Noise reduction node	Accepts 0.1 µF capacitor to shunt reference amplifier noise, directly lowering output RMS noise to 30 µV.
4 - OUT	Regulated output terminal	Delivers stable 2.5 V to load; requires ≥2.2 µF ceramic output capacitor for stability per datasheet.
5 - IN	Unregulated input supply	Accepts 2.5 V–14 V input; for 2.5 V output, minimum valid input is V_OUT + 0.5 V = 3.0 V.

Key Features

Feature	Design Value
Ultra-low noise regulation	30 µV_rms output noise with 0.1 µF bypass cap - eliminates need for post-LDO filtering in sensitive analog stages.
Sub-µA shutdown current	0.1 µA max. I_q in OFF state - preserves battery charge during extended system sleep modes.
Integrated protection	Auto-recovering current limit and thermal shutdown - prevents damage during short-circuit or ambient overheating without external circuitry.
Wide input voltage range	Operates from 3.0 V to 14 V for 2.5 V output - supports diverse input sources including buck-boost converters and multi-cell batteries.
Small-footprint packaging	SOT23-5L (2.95 × 1.60 mm) - enables high-density layouts in wearables, medical patches, and compact sensor modules.

Applications

Wearable Health Sensors

Industrial Wireless Transmitters

Use Scenario: Powering ultra-low-power ECG/PPG analog front-ends in chest-worn monitors with coin-cell batteries.

IC Role / Device Role / Timing Role: Provides clean, stable 2.5 V bias to instrumentation amplifiers and 16-bit SAR ADCs, rejecting supply noise from digital MCU switching.

Use Value: 30 µV_rms noise ensures <1 LSB noise floor for 16-bit conversion at 1 kSPS, extending usable battery life via 0.1 µA shutdown current.

Use Scenario: Supplying LoRaWAN or NB-IoT transceiver ICs in remote environmental sensor nodes deployed for >10-year field life.

IC Role / Device Role / Timing Role: Delivers regulated 2.5 V to RF power amplifier and crystal oscillator circuits during transmit bursts and deep-sleep cycles.

Use Value: 290 mV dropout allows operation down to 2.79 V input, maximizing energy extraction from aging primary cells; shutdown pin synchronizes with MCU sleep states.

Portable Test Equipment

Automotive Cabin Sensors

Use Scenario: Biasing precision voltage references and DACs in handheld multimeters and calibrators powered by rechargeable Li-ion packs.

IC Role / Device Role / Timing Role: Acts as low-noise post-regulator after a switching DC/DC stage, suppressing switching ripple before analog signal paths.

Use Value: 55 dB PSRR at 400 Hz rejects buck converter ripple; ±2 % output tolerance ensures traceable measurement accuracy without calibration drift.

Use Scenario: Powering MEMS accelerometers and humidity sensors in automotive HVAC or occupancy detection modules within AEC-Q200-compliant assemblies.

IC Role / Device Role / Timing Role: Supplies 2.5 V to sensor signal conditioning ICs in non-safety-critical cabin subsystems operating across -40 °C to +125 °C junction range.

Use Value: Thermal shutdown and current limiting protect against wiring faults; 0.09 mV/°C tempco minimizes sensor offset drift over temperature.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLV70225DBVR	2.5 V fixed, 300 mA, 225 mV dropout @ 300 mA, 35 µV_rms noise, no dedicated bypass pin	Higher current capacity but higher noise floor and no Bypass pin for noise tuning	Select when >150 mA load or smaller dropout is required; accept higher noise or add external RC filter.
MCP1703T-2502E/MB	2.5 V fixed, 250 mA, 600 mV dropout @ 250 mA, 40 µV_rms noise, no shutdown pin	Lacks enable/shutdown functionality and has higher dropout and noise than LK112M25TR	Choose only if shutdown control is unnecessary and board space permits larger dropout margin.

Compared with TLV70225DBVR and MCP1703T-2502E/MB, the LK112M25TR uniquely combines sub-µA shutdown, dedicated noise-bypass pin, and 290 mV dropout in SOT23-5L - making it optimal for ultra-low-power, noise-sensitive applications where precise enable control and minimal external components are critical.

Availability

LK112M25TR is available at Aetrix Electronics and suitable for wearable health monitors, industrial wireless transmitters, and portable test equipment requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.

Supply support for LK112M25TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.

The LK112 series belongs to ST's precision linear regulator product line, engineered specifically for ultra-low-noise, low-quiescent-current power delivery in battery-powered and signal-integrity-critical applications.

FAQ

What is the minimum input voltage required for LK112M25TR to regulate at 2.5 V?

The LK112M25TR requires a minimum input voltage of V_OUT + 0.5 V = 3.0 V for proper regulation at 2.5 V output. This is specified in the datasheet for V_OUT > 2 V. Below 3.0 V, dropout behavior begins and output voltage drops linearly with input.

Can the Bypass pin be left unconnected?

No - leaving the Bypass pin floating degrades noise performance. The datasheet specifies a 0.1 µF ceramic capacitor must be placed between Bypass and GND to achieve the rated 30 µV_rms output noise. Omitting it results in higher broadband noise due to unfiltered reference amplifier output.

Does LK112M25TR require an input capacitor?

Yes - a minimum 1 µF ceramic input capacitor is required for stability and transient response, as confirmed in Section 4 (Electrical Characteristics) of the datasheet. It suppresses source impedance effects and prevents oscillation during load steps.

Is LK112M25TR qualified for automotive use?

No - the LK112M25TR is not AEC-Q100 qualified and is not recommended for automotive applications. Its datasheet explicitly excludes use in automotive environments, and its qualification scope covers industrial and consumer temperature ranges (–40 °C to +125 °C junction), not automotive-grade reliability testing.

LK112M25TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: SC-74A, SOT-753

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 14V

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.35V @ 150mA

Current - Output:: 150mA

Current - Quiescent (Iq):: 250 µA

Current - Supply (Max):: -

PSRR:: 55dB (400Hz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -30°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

LK112M25TR FAQ

1.How can I place an order for LK112M25TR through Aetrix?

Please submit a Request for Quotation (RFQ) for LK112M25TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LK112M25TR reliable?

The price and inventory of LK112M25TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LK112M25TR is usually 5 days.

3.What payment methods are accepted for LK112M25TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LK112M25TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LK112M25TR?

LK112M25TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LK112M25TR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LK112M25TR?

For technical support, including LK112M25TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LK112M25TR requirements.

6.How does Aetrix verify that LK112M25TR is sourced from the original manufacturer or authorized distributors?

All LK112M25TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LK112M25TR meets industry standards.

7.What is the process for return or replacement of LK112M25TR?

All LK112M25TR units undergo pre-shipment inspection (PSI). If there is an issue with LK112M25TR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LK112M25TR part is unused and in its original packaging.

Return procedure for LK112M25TR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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