STMicroelectronics LDL1117S30R

Overview

LDL1117S30R from STMicroelectronics is a fixed 3.0 V, 1.2 A low-dropout linear voltage regulator in SOT223 package, featuring 350 mV typical dropout at full load, 87 dB PSRR at 120 Hz, and ±2% output accuracy at 25°C. It operates from 2.6 V to 18 V input, supports industrial temperature range (−40°C to +125°C), and integrates thermal shutdown, current limiting, and SOA protection - ideal for DC-DC post-regulation in motherboard point-of-load systems.

For engineers reviewing the LDL1117S30R datasheet, LDL1117S30R pinout, LDL1117S30R application, or LDL1117S30R equivalent, this page delivers verified electrical specs, validated SOT223 terminal mapping, real-world use cases in SMPS secondary regulation and consumer power rails, and technically grounded alternative part comparisons.

Technical Context

The LDL1117S30R employs a PNP pass transistor architecture enabling stable 3.0 V output with minimal dropout across its 1.2 A load range. Its internal bandgap reference and error amplifier deliver tight line/load regulation (≤15 mV load variation) and low output noise (60 µV_RMS, 10 Hz–100 kHz).

Thermal protection activates at 175°C junction temperature with 25°C hysteresis, while SOA-based current limiting caps peak output at ~2 A depending on (VIN−VOUT). The device requires only 1 µF input and 4.7 µF ceramic output capacitance for guaranteed stability across −40°C to +125°C.

Key Specifications

Pinout & Package

SOT223 package with exposed tab thermally and electrically connected to VOUT; standard 3-pin configuration optimized for thermal dissipation in space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDL1117S33R and TLV1117-33CDCYR, the LDL1117S30R uniquely delivers precise 3.0 V output with industry-leading 87 dB PSRR and sub-0.5 mA quiescent current - critical for noise-sensitive digital loads and energy-efficient industrial designs where voltage margin is tight.

Availability

LDL1117S30R is available at Aetrix Electronics and suitable for consumer power rails, industrial SMPS post-regulation, and motherboard point-of-load applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LDL1117S30R 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, and analog devices for industrial, automotive, and consumer markets.

The LDL1117 series belongs to ST's high-PSRR LDO portfolio, engineered specifically for noise-critical post-regulation in switched-mode power supplies and embedded systems demanding precision, reliability, and thermal robustness.

FAQ

What is the minimum input voltage required for stable 3.0 V output at 1.2 A?

The LDL1117S30R requires VIN ≥ VOUT + VDROP = 3.0 V + 0.6 V = 3.6 V for guaranteed regulation at 1.2 A (max dropout is 600 mV per datasheet Table 4). At 25°C and light load, it can operate down to 2.6 V input, but full-load performance mandates ≥3.6 V input to avoid dropout.

Can the LDL1117S30R replace a 3.3 V LDO in an existing design?

No - the LDL1117S30R is a fixed 3.0 V device and cannot substitute for 3.3 V logic rails without verifying downstream component voltage tolerance. Its pinout and thermal characteristics match other LDL1117 variants, but output voltage mismatch risks undervoltage lockout or functional failure in 3.3 V–rated ICs.

Is an external bypass capacitor required for noise reduction?

No external bypass capacitor is required beyond the specified 4.7 µF ceramic output capacitor. The 60 µV_RMS noise performance is achieved with standard X5R/X7R MLCCs; adding a small (1–10 nF) NP0/C0G capacitor in parallel may further reduce high-frequency noise but is not necessary for datasheet compliance.

How does the thermal shutdown behave during sustained overload?

When junction temperature reaches 175°C (typ.), the device shuts down completely. It remains off until temperature falls to ~150°C (25°C hysteresis), then resumes normal operation automatically. This auto-retry behavior prevents permanent latch-up while protecting against prolonged thermal stress during intermittent overloads.