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

STMicroelectronics LD1117S30TR

Name: LD1117S30TR
Brand: STMicroelectronics
SKU: LD1117S30TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD1117S30TR

Manufacturer:: STMicroelectronics

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

Package:: TO-261-4, TO-261AA

Datasheet:: LD1117S30TR.pdf

Description:: IC REG LINEAR 3V 800MA SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:1,052

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Product details

Overview

LD1117S30TR from STMicroelectronics is a fixed-output 3.3 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 at 120 Hz - used in embedded power rails for microcontrollers, sensors, and industrial I/O modules.

For engineers reviewing the LD1117S30TR datasheet, LD1117S30TR pinout, LD1117S30TR application, or LD1117S30TR equivalent, this page delivers verified technical context, package-specific pin functions, real-world application constraints, and validated alternative options for stable 3.3 V regulation in space- and thermal-constrained designs.

Technical Context

The LD1117S30TR uses an NPN pass transistor architecture, enabling high efficiency by routing quiescent current primarily into the load rather than ground - unlike PNP-based regulators. Its internal bandgap reference and trimming circuitry achieve tight output accuracy without external components.

It integrates thermal shutdown and current limiting, operates with only a 10 µF output capacitor for stability, and maintains regulation across input voltages from 4.75 V to 15 V while sustaining 3.3 V output under full 800 mA load across –40 °C to +125 °C junction temperature range.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 3.3 V ±1 % at 25 °C; ±3.5 % over full temperature range - ensures reliable logic-level compatibility with 3.3 V microcontrollers and FPGAs.
Dropout Voltage	1.0 V typ. at 100 mA; 1.2 V max. at 800 mA - enables operation from 4.75 V input (e.g., 5 V rail) with margin for ripple and aging.
Output Current	800 mA continuous; 950 mA typ. peak - supports moderate-power peripherals like RS-485 transceivers or small LCD backlights.
Supply Rejection	75 dB typ. at 120 Hz - suppresses ripple from upstream switching supplies, reducing need for additional filtering.
Thermal Resistance	R_thJA = 100 °C/W (SOT-223); R_thJC = 15 °C/W - requires minimal copper area for thermal relief in PCB layout.
Quiescent Current	5–10 mA - remains stable across input voltage and load, simplifying standby power estimation.
Stability Capacitor	10 µF minimum ceramic or tantalum - eliminates need for complex compensation networks.

Pinout & Package

LD1117S30TR is supplied in SOT-223 package, where the exposed tab is electrically connected to V_OUT and serves as the primary thermal path. Pin 1 is VIN, Pin 2 is GND, Pin 3 is VOUT, and Pin 4 is the thermal tab (VOUT).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (VIN)	Input voltage supply	Accepts 4.75–15 V DC; must be decoupled locally to limit noise injection and transient response degradation.
Pin 2 (GND)	Ground reference	Low-impedance return path for both regulator control circuitry and load current; separate analog/digital grounding not required.
Pin 3 (VOUT)	Regulated output	Delivers stable 3.3 V to load; connects directly to tab (Pin 4), requiring isolation from PCB ground plane unless thermally coupled via solder mask opening.
Pin 4 (TAB)	Thermal pad / VOUT	Electrically tied to VOUT; must be soldered to ≥200 mm² copper pour for thermal performance; no electrical isolation needed.

Key Features

Feature	Design Value
Low dropout operation	1.0 V typical at 100 mA enables use with narrow input margins (e.g., battery-powered 5 V systems).
High PSRR	75 dB at 120 Hz reduces sensitivity to switching supply noise, lowering BOM cost for clean 3.3 V rails.
Tight initial tolerance	±1 % at 25 °C eliminates need for post-production calibration in precision analog or ADC reference applications.
Integrated protection	Thermal shutdown and current limiting prevent damage during overload or poor heatsinking conditions.
Minimal external components	Only one 10 µF output capacitor required - simplifies layout, improves reliability, and reduces footprint vs. multi-capacitor LDOs.

Applications

Industrial PLC I/O Module

Embedded Microcontroller Power

Use Scenario: Powering isolated digital I/O channels in DIN-rail mounted programmable logic controllers.

IC Role / Device Role / Timing Role: Primary 3.3 V local regulator for FPGA configuration logic, level-shifting buffers, and optocoupler drivers.

Use Value: 1 V dropout allows direct derivation from 5 V backplane supply; ±1 % tolerance ensures consistent timing margin for SPI/I²C interfaces.

Use Scenario: Supplying core voltage to ARM Cortex-M4 microcontrollers in edge sensor nodes.

IC Role / Device Role / Timing Role: Main system regulator for MCU VDD, ADC reference, and USB PHY interface.

Use Value: 75 dB PSRR suppresses noise from shared 5 V SMPS, preserving ADC ENOB and USB signal integrity.

Medical Patient Monitor Front-End

Automotive Body Control Module

Use Scenario: Providing clean 3.3 V to analog front-end amplifiers and ECG signal conditioning circuits.

IC Role / Device Role / Timing Role: Low-noise local regulator for precision analog signal chain powering.

Use Value: 100 µV output noise (typ.) avoids introducing measurable offset or drift in sub-mV biomedical signals.

Use Scenario: Regulating 3.3 V for CAN transceiver and LIN controller in non-safety-critical body electronics.

IC Role / Device Role / Timing Role: Secondary regulator downstream of main 5 V vehicle bus supply.

Use Value: –40 °C to +125 °C operating range meets AEC-Q100 Grade 2 ambient requirements without derating.

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed 3.3 V LDO regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LD1117S33TR	Same die, identical specs, alternate order code for same 3.3 V variant - differs only in tape-and-reel packaging marking.	No functional difference; used interchangeably in production with identical thermal and electrical behavior.	Select based on distributor stock availability or preferred reel size (e.g., 2500 vs. 4000 pcs/reel).
TLV1117-33CDCYR	1.2 V dropout min. at 800 mA; 70 dB PSRR; ±2 % tolerance over temperature - higher dropout and looser accuracy than LD1117S30TR.	Suitable for less demanding applications where 5 V input margin is >1.5 V and ±3.3 V tolerance is acceptable.	Choose when TI's qualification or long-term availability outweighs ST's tighter tolerance and lower dropout.

Compared with LD1117S30TR, LD1117S33TR offers identical performance with packaging-level differentiation, while TLV1117-33CDCYR trades 0.2 V higher dropout and ±1 % wider tolerance for broader vendor support - making LD1117S30TR optimal for thermally constrained, precision 3.3 V rails.

Availability

LD1117S30TR is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and automotive body electronics requiring stable component supply with guaranteed long-term manufacturability and traceable sourcing.

Supply support for LD1117S30TR 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The LD1117 series belongs to ST's general-purpose linear regulator product line, designed specifically for cost-sensitive, thermally constrained applications requiring high accuracy and robustness without external compensation.

FAQ

What is the maximum input voltage for LD1117S30TR?

The absolute maximum DC input voltage is 15 V per the datasheet. Operation above 15 V risks permanent damage due to junction breakdown. For reliable long-term use, keep VIN ≤14.5 V to maintain margin against transients and ensure thermal safety at full load.

Can LD1117S30TR be used with ceramic output capacitors?

Yes - the regulator is stable with 10 µF or greater X5R/X7R ceramic capacitors. Unlike older LDOs, it does not require ESR-based damping; however, avoid using ultra-low-ESR types below 1 µΩ without verifying phase margin in simulation or bench testing.

Does LD1117S30TR require an input capacitor?

An input capacitor is not mandatory for stability but strongly recommended: a 1 µF ceramic capacitor placed within 5 mm of VIN/GND pins reduces high-frequency noise coupling and improves transient response during load steps - especially critical in noisy switcher-fed systems.

How is thermal performance affected if the SOT-223 tab is not soldered to PCB copper?

Without soldering the tab to ≥200 mm² of 2 oz copper, R_thJA degrades from 100 °C/W to ~180 °C/W. At 800 mA, this raises junction temperature by ~65 °C - risking thermal shutdown or accelerated parametric drift. Full tab soldering is essential for rated performance.

LD1117S30TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 15V

Voltage - Output (Min/Fixed):: 3V

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:: SOT-223

LD1117S30TR FAQ

1.How can I place an order for LD1117S30TR through Aetrix?

Please submit a Request for Quotation (RFQ) for LD1117S30TR 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 LD1117S30TR reliable?

The price and inventory of LD1117S30TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD1117S30TR is usually 5 days.

3.What payment methods are accepted for LD1117S30TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD1117S30TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD1117S30TR?

LD1117S30TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD1117S30TR 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 LD1117S30TR?

For technical support, including LD1117S30TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD1117S30TR requirements.

6.How does Aetrix verify that LD1117S30TR is sourced from the original manufacturer or authorized distributors?

All LD1117S30TR 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 LD1117S30TR meets industry standards.

7.What is the process for return or replacement of LD1117S30TR?

All LD1117S30TR units undergo pre-shipment inspection (PSI). If there is an issue with LD1117S30TR, 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 LD1117S30TR part is unused and in its original packaging.

Return procedure for LD1117S30TR:

1.Submit a request within 90 days.

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

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