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

STMicroelectronics LD1117D25

Name: LD1117D25
Brand: STMicroelectronics
SKU: LD1117D25
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD1117D25

Manufacturer:: STMicroelectronics

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

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: LD1117D25.pdf

Description:: IC REG LINEAR 2.5V 800MA 8SO

Quantity:: RFQ Add To RFQ list

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Inventory:3,333

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Product details

Overview

LD1117D25 from STMicroelectronics is a fixed-output 2.5 V low-dropout linear voltage regulator delivering up to 800 mA, featuring 1 V typical dropout at 100 mA, ±1 % output voltage tolerance at 25 °C, and 75 dB supply voltage rejection. It serves as a primary post-regulator in embedded power rails for microcontrollers, sensors, and analog circuitry requiring stable 2.5 V bias.

For engineers reviewing the LD1117D25 datasheet, LD1117D25 pinout, LD1117D25 application, or LD1117D25 equivalent, this page delivers verified electrical specs, thermal performance data, package-specific layout guidance, and real-world use cases - all grounded in ST's production-grade documentation (DocID2572 Rev 38).

Technical Context

The LD1117D25 uses an NPN pass transistor architecture, enabling high efficiency by routing quiescent current primarily into the load rather than ground. Its internal bandgap reference and error amplifier maintain regulation across input voltages from 3.9 V to 15 V with minimal external components.

Thermal protection and current limiting are integrated on-die, with junction temperature operating range of 0 to +125 °C (standard version) and thermal resistance as low as 5 °C/W (TO-220) or 8 °C/W (DPAK), enabling robust operation under sustained 800 mA loads without external heatsinking in many applications.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.5 V, ±1 % tolerance at 25 °C ensures precision biasing for ADC references and sensor excitation circuits.
Max Output Current	800 mA continuous, supporting power delivery to mid-complexity MCUs and peripheral ICs without external boost stages.
Dropout Voltage	1.0 V typ. at 100 mA; enables operation from 3.9 V input to deliver clean 2.5 V - critical for battery-powered systems near end-of-life.
Supply Voltage Rejection	75 dB typ. at 120 Hz, suppressing ripple from upstream switching regulators or noisy DC/DC converters.
Quiescent Current	5–10 mA over input range, minimizing no-load power loss in always-on subsystems.
Stability Capacitor	Only 10 µF minimum ceramic or tantalum output capacitor required - simplifies layout and reduces BOM count.
Operating Input Range	3.9 V to 15 V DC, compatible with 5 V and 12 V system rails while maintaining regulation margin.

Pinout & Package

LD1117D25 is available in SOT-223, DPAK (TO-252), SO-8, and TO-220 packages. The TAB is internally connected to VOUT in all variants, serving as both thermal path and output terminal.

Pin/Terminal	Circuit Role	Design Meaning
IN	Input voltage supply	Accepts unregulated DC input; requires local 10 µF decoupling to ensure stability and transient response.
OUT	Regulated output	Delivers fixed 2.5 V; electrically tied to exposed thermal pad (TAB) - must be soldered to PCB copper for thermal management.
GND	Ground reference	Return path for load current and internal bias; requires low-impedance connection to minimize noise coupling.

Key Features

Feature	Design Value
NPN pass transistor topology	Directs quiescent current into load instead of ground, improving efficiency and reducing standby power loss.
On-chip current & thermal limiting	Prevents damage during short-circuit or overload events without external foldback circuitry.
±1 % output tolerance at 25 °C	Meets tight accuracy requirements for precision analog interfaces and reference voltage generation.
Low 10 µF output capacitance requirement	Enables use of small, cost-effective ceramic capacitors - eliminates need for large electrolytics or complex compensation networks.
75 dB SVR at 120 Hz	Effectively filters switching noise from upstream DC/DC converters, preserving signal integrity in mixed-signal designs.

Applications

Industrial Sensor Node

USB-Powered MCU Board

Use Scenario: A battery-backed environmental sensor node with I²C temperature/humidity sensor and low-power MCU operates from a 3.7 V Li-ion cell.

IC Role / Device Role / Timing Role: LD1117D25 provides stable 2.5 V reference and analog supply for sensor excitation and ADC reference, maintaining accuracy across discharge curve.

Use Value: 1 V dropout allows >2.0 V output down to 3.7 V input - extending usable battery life by ~15% compared to higher-dropout regulators.

Use Scenario: A USB-powered development board hosting an ARM Cortex-M4 MCU, SPI flash, and op-amp signal chain draws peak 650 mA.

IC Role / Device Role / Timing Role: LD1117D25 acts as secondary LDO after a 5 V USB input, cleaning switching noise from upstream buck converter and supplying clean 2.5 V to analog peripherals.

Use Value: 75 dB SVR suppresses 100–200 kHz ripple from USB PD source, reducing ADC quantization noise by ≥12 dBFS.

Medical Point-of-Care Device

Automotive Body Control Module

Use Scenario: A portable blood glucose meter uses a 3.3 V main rail; its optical sensor and transimpedance amplifier require ultra-stable 2.5 V bias.

IC Role / Device Role / Timing Role: LD1117D25 supplies regulated 2.5 V to photodiode front-end and reference ladder, rejecting noise from digital switching and display drivers.

Use Value: ±1 % tolerance at 25 °C and 0.5 % temperature stability ensure measurement repeatability within clinical accuracy thresholds (±2%).

Use Scenario: A BCM supplies 2.5 V to LIN transceiver logic and EEPROM interface in a 12 V automotive system with wide input transients.

IC Role / Device Role / Timing Role: LD1117D25 provides isolated, low-noise 2.5 V rail downstream of a 5 V pre-regulator, surviving load-dump pulses via upstream protection.

Use Value: DPAK package offers 8 °C/W R_thJA, enabling 800 mA operation at 85 °C ambient without heatsink - reducing mechanical complexity and cost.

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM1117DT-2.5/NOPB	Higher dropout (1.2 V min), ±2 % tolerance, no guaranteed 800 mA rating above 85 °C.	Limited thermal headroom in compact enclosures; less suitable for sustained high-current loads at elevated ambient.	Select when cost sensitivity outweighs thermal or accuracy requirements, and input headroom exceeds 1.3 V.
AP2210K-2.5TRG1	Lower max current (300 mA), 600 mV dropout, ±2 % tolerance, different pinout (SOT-23-5).	Not viable for >500 mA loads; unsuitable as direct replacement due to current and package mismatch.	Consider only for space-constrained, low-power applications where 300 mA suffices and footprint change is acceptable.

Compared with LM1117DT-2.5/NOPB, LD1117D25 delivers tighter tolerance and lower dropout for improved efficiency and accuracy; versus AP2210K-2.5TRG1, it supports triple the output current in identical thermal packages - making it the preferred choice for industrial and automotive power rails demanding reliability and headroom.

Availability

LD1117D25 is available at Aetrix Electronics and suitable for industrial sensor nodes, USB-powered MCU boards, medical point-of-care devices, and automotive body control modules requiring stable component supply and long-term manufacturability.

Supply support for LD1117D25 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 specializing in power management, microcontrollers, and analog ICs, with manufacturing and design centers across Europe, Asia, and the Americas.

The LD1117 series belongs to ST's general-purpose linear regulator product line, engineered for cost-sensitive, high-reliability applications in industrial automation, consumer electronics, and automotive subsystems where simplicity, thermal robustness, and proven field performance are essential.

FAQ

What is the minimum input voltage required for LD1117D25 to regulate at full 800 mA?

The LD1117D25 requires a minimum input-to-output differential of 1.10 V at 800 mA (per Table 5, TJ = 25 °C). With a nominal 2.5 V output, the absolute minimum input is 3.6 V. However, for reliable operation across temperature and load transients, ST recommends ≥3.9 V input - validated in the datasheet's test conditions for full 800 mA capability.

Can LD1117D25 be used with ceramic output capacitors?

Yes - the LD1117D25 is stable with ceramic capacitors as low as 10 µF, provided they meet the ESR specification (≥0.3 Ω recommended per ST AN2821). Unlike older LDOs, it does not require high-ESR tantalum or aluminum electrolytics, enabling smaller footprints and improved reliability in vibration-prone environments.

How does thermal performance differ between SOT-223 and DPAK packages?

DPAK (TO-252) offers 8 °C/W R_thJA vs. 110 °C/W for SOT-223 (Table 2), meaning DPAK dissipates heat ~14× more effectively in standard PCB layouts. At 800 mA and 1 V dropout (0.8 W dissipation), DPAK maintains ~15 °C junction rise above ambient, while SOT-223 would exceed safe limits without aggressive copper pours - making DPAK the default choice for high-current designs.

Is LD1117D25 qualified for automotive applications?

The standard LD1117D25 is not AEC-Q100 qualified. However, ST offers the LD1117D25TR - a variant in DPAK package with extended temperature range (−40 to +125 °C) and automotive-grade screening. For non-automotive industrial or medical use, the standard part meets full-spec performance; for automotive ECUs, the TR variant must be specified and sourced accordingly.

LD1117D25 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tube

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 15V

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

Voltage - Output (Max):: -

Voltage Dropout (Max):: 1.2V @ 800mA

Current - Output:: 800mA

Current - Quiescent (Iq):: 10 mA

Current - Supply (Max):: -

PSRR:: 75dB (120Hz)

Control Features:: -

Protection Features:: Over Current, Over Temperature

Operating Temperature:: 0°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

LD1117D25 FAQ

1.How can I place an order for LD1117D25 through Aetrix?

Please submit a Request for Quotation (RFQ) for LD1117D25 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 LD1117D25 reliable?

The price and inventory of LD1117D25 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD1117D25 is usually 5 days.

3.What payment methods are accepted for LD1117D25?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD1117D25 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD1117D25?

LD1117D25 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD1117D25 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 LD1117D25?

For technical support, including LD1117D25 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD1117D25 requirements.

6.How does Aetrix verify that LD1117D25 is sourced from the original manufacturer or authorized distributors?

All LD1117D25 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 LD1117D25 meets industry standards.

7.What is the process for return or replacement of LD1117D25?

All LD1117D25 units undergo pre-shipment inspection (PSI). If there is an issue with LD1117D25, 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 LD1117D25 part is unused and in its original packaging.

Return procedure for LD1117D25:

1.Submit a request within 90 days.

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

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