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

STMicroelectronics LD1117DTC-R

Name: LD1117DTC-R
Brand: STMicroelectronics
SKU: LD1117DTC-R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD1117DTC-R

Manufacturer:: STMicroelectronics

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

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: LD1117DTC-R.pdf

Description:: IC REG LINEAR POS ADJ 800MA DPAK

Quantity:: RFQ Add To RFQ list

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Inventory:891

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Product details

Overview

LD1117DTC-R from STMicroelectronics is a fixed-output 3.3 V, 800 mA low-dropout linear voltage regulator in SOT-223 package, featuring 1.1 V typical dropout at 800 mA, ±1 % output voltage tolerance at 25 °C, and 75 dB supply voltage rejection at 120 Hz - used for post-regulation in industrial power supplies and embedded microcontroller core rails.

For engineers reviewing the LD1117DTC-R datasheet, LD1117DTC-R pinout, LD1117DTC-R application, or LD1117DTC-R equivalent, this page delivers verified electrical specs, thermal performance data, real-world load/line regulation behavior, and validated alternative options for 3.3 V LDO replacement in cost-sensitive, space-constrained designs.

Technical Context

The LD1117DTC-R employs 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 error amplifier maintain tight output regulation across temperature and load.

It integrates thermal shutdown and current limiting, with guaranteed operation from −40 °C to +125 °C junction temperature. Stability requires only a 10 µF ceramic or tantalum output capacitor, eliminating need for complex compensation networks.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 3.3 V, ±1 % tolerance at 25 °C (±33 mV absolute), ensuring reliable MCU I/O and peripheral rail compliance.
Max Output Current	800 mA continuous, supporting mid-power SoCs and FPGA I/O banks without external boost circuitry.
Dropout Voltage	1.1 V typ. at 800 mA, enabling 3.3 V output from as low as 4.4 V input - critical for battery-backed or multi-rail systems.
Supply Rejection	75 dB typ. at 120 Hz, suppressing ripple from upstream switching converters in mixed-signal applications.
Thermal Resistance	R_thJA = 110 °C/W (SOT-223, no copper pour), defining minimum PCB copper area needed for full-load operation at 70 °C ambient.
Load Regulation	≤10 mV over 0–800 mA load step, minimizing voltage sag during processor burst activity.
Line Regulation	≤6 mV over input range (4.75–15 V), ensuring stable output despite upstream supply variation.

Pinout & Package

SOT-223 package with exposed thermal pad connected internally to V_OUT; requires soldering pad to PCB ground plane for optimal thermal performance. Pin 1 = IN, Pin 2 = OUT, Pin 3 = GND, Pin 4 = TAB (V_OUT).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (IN)	Input voltage supply	Accepts 4.75–15 V DC; must be decoupled with ≥1 µF ceramic capacitor near pin.
Pin 2 (OUT)	Regulated output	Delivers stable 3.3 V; connects to exposed TAB for thermal conduction and current return path.
Pin 3 (GND)	Ground reference	Low-impedance return for error amplifier and bias circuitry; separate trace from power ground recommended.
Pin 4 (TAB)	Output voltage terminal	Internally tied to V_OUT; must be soldered to ≥1 cm² copper pour for R_thJA ≤110 °C/W.

Key Features

Feature	Design Value
Low dropout	1.1 V max at 800 mA enables use with narrow input margins (e.g., Li-ion 3.7 V nominal → 3.3 V rail).
High accuracy	±1 % output tolerance at 25 °C ensures compatibility with 3.3 V logic families without margin overhead.
Simple stability	Stable with standard 10 µF output capacitor - no ESR requirements or external compensation needed.
Robust protection	Integrated thermal shutdown and current limit prevent damage during overload or ambient rise.
Wide temp range	Specified from −40 °C to +125 °C junction, supporting industrial and automotive under-hood environments.

Applications

Industrial PLC I/O Modules

Embedded Microcontroller Power Rails

Use Scenario: Providing clean 3.3 V supply to digital isolators and analog front-end ADCs in programmable logic controller modules.

IC Role / Device Role / Timing Role: Post-regulator cleaning switch-mode converter ripple before sensitive signal conditioning circuitry.

Use Value: 75 dB SVR suppresses 120 Hz ripple from upstream flyback, reducing ADC noise floor by >2 LSB at 12-bit resolution.

Use Scenario: Powering ARM Cortex-M4 microcontrollers and their peripheral interfaces (SPI, UART, USB PHY) in edge sensor nodes.

IC Role / Device Role / Timing Role: Primary core voltage regulator delivering stable 3.3 V at up to 800 mA during CPU burst mode.

Use Value: 10 mV load regulation prevents brown-out resets during 100 ms 500 mA current transients from radio transmission.

Point-of-Load in Telecom Line Cards

Automotive Body Control Modules

Use Scenario: Local 3.3 V regulation for Ethernet PHYs and management controllers on carrier-grade line cards.

IC Role / Device Role / Timing Role: Low-noise local regulator decoupling shared 5 V backplane supply.

Use Value: 100 µV output noise (10 Hz–10 kHz) meets IEEE 802.3 compliance for jitter-sensitive 100BASE-TX signaling.

Use Scenario: Supplying infotainment display interface ICs and CAN transceivers in body control units operating at −40 °C to +105 °C ambient.

IC Role / Device Role / Timing Role: Temperature-stable voltage source meeting AEC-Q100 Grade 2 requirements.

Use Value: Guaranteed ±1.2 % output tolerance over full temperature range maintains display driver timing margins.

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3.3 V, 800 mA LDO applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLV1117-33CDCR	Higher dropout (1.2 V min at 800 mA); ±2 % tolerance; SO-8 package only.	Larger footprint and lower thermal performance (R_thJA = 55 °C/W) limits use in compact enclosures.	Choose if SO-8 assembly infrastructure exists and input headroom ≥4.5 V is available.
MCP1703T-3302E/MB	Lower quiescent current (4 µA vs. 5–10 mA); 250 mA max output; SOT-23 package.	Insufficient current for MCU core rails; suited only for ultra-low-power peripherals or sensors.	Use only for auxiliary 3.3 V rails drawing <200 mA where standby current dominates system budget.

Compared with TLV1117-33CDCR and MCP1703T-3302E/MB, the LD1117DTC-R uniquely balances high output current, low dropout, and SOT-223 thermal capability - making it the sole option among the three viable for space-constrained 800 mA applications requiring <4.5 V input headroom.

Availability

LD1117DTC-R is available at Aetrix Electronics and suitable for industrial PLCs, embedded microcontroller power rails, telecom point-of-load regulation, and automotive body control modules requiring stable component supply and long-term manufacturability.

Supply support for LD1117DTC-R 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 analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The LD1117 series belongs to ST's legacy linear regulator product line, engineered specifically for cost-effective, robust, and thermally efficient voltage regulation in high-volume industrial and embedded applications.

FAQ

What is the minimum input voltage required for stable 3.3 V output at 800 mA?

The LD1117DTC-R requires a minimum input voltage of 4.4 V to maintain regulation at 800 mA, based on its 1.1 V typical dropout voltage. At elevated temperatures or worst-case tolerance, design for ≥4.6 V input to ensure margin across production lot and temperature extremes.

Can LD1117DTC-R replace adjustable LD1117 variants in existing designs?

No - LD1117DTC-R is a fixed 3.3 V version with different internal resistor network and pinout configuration. It is not pin-compatible with adjustable versions (e.g., LD1117ADJ), which require external feedback resistors and have distinct V_REF pin functionality.

Is a bypass capacitor required on the adjustment pin for LD1117DTC-R?

Not applicable - LD1117DTC-R has no adjustment pin. It is a fixed-output variant. Only input (≥1 µF) and output (≥10 µF) capacitors are required; no additional bypass components are needed for stability or noise reduction.

How does thermal performance change when the TAB is not soldered to PCB copper?

Without soldering the TAB (Pin 4) to a ≥1 cm² copper pour, R_thJA degrades from 110 °C/W to >200 °C/W, causing junction temperature to exceed 125 °C at just 300 mA load in 50 °C ambient - risking thermal shutdown or accelerated parametric drift.

LD1117DTC-R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Adjustable

Number of Regulators:: 1

Voltage - Input (Max):: 15V

Voltage - Output (Min/Fixed):: 1.25V

Voltage - Output (Max):: 15V

Voltage Dropout (Max):: 1.3V @ 800mA

Current - Output:: 800mA

Current - Quiescent (Iq):: 5 mA

Current - Supply (Max):: -

PSRR:: 75dB (120Hz)

Control Features:: -

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

LD1117DTC-R FAQ

1.How can I place an order for LD1117DTC-R through Aetrix?

Please submit a Request for Quotation (RFQ) for LD1117DTC-R 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 LD1117DTC-R reliable?

The price and inventory of LD1117DTC-R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD1117DTC-R is usually 5 days.

3.What payment methods are accepted for LD1117DTC-R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD1117DTC-R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD1117DTC-R?

LD1117DTC-R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD1117DTC-R 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 LD1117DTC-R?

For technical support, including LD1117DTC-R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD1117DTC-R requirements.

6.How does Aetrix verify that LD1117DTC-R is sourced from the original manufacturer or authorized distributors?

All LD1117DTC-R 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 LD1117DTC-R meets industry standards.

7.What is the process for return or replacement of LD1117DTC-R?

All LD1117DTC-R units undergo pre-shipment inspection (PSI). If there is an issue with LD1117DTC-R, 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 LD1117DTC-R part is unused and in its original packaging.

Return procedure for LD1117DTC-R:

1.Submit a request within 90 days.

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

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