STMicroelectronics LD1117V50C

Overview

LD1117V50C from STMicroelectronics is a fixed-output 5.0 V, low-dropout linear voltage regulator delivering up to 800 mA output current with 1.0 V typical dropout at 100 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 logic.

For engineers reviewing the LD1117V50C datasheet, LD1117V50C pinout, LD1117V50C application, or LD1117V50C equivalent, this page delivers verified package mapping (SOT-223), thermal resistance data (R_thJA = 110 °C/W), minimum stability capacitor requirement (10 µF), dropout behavior across load (1.10–1.30 V at 800 mA), and real-world substitution guidance against LM1117-5.0 and MIC5205-5.0.

Technical Context

The LD1117V50C 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 trimming circuitry achieve tight output accuracy without external resistors.

It integrates thermal shutdown and current limiting, operates over –40 °C to +125 °C junction temperature, and maintains regulation with input-to-output differentials as low as 1.1 V at full 800 mA load - making it suitable for 5 V rail generation from 6.5–15 V sources in space-constrained PCBs.

Key Specifications

Pinout & Package

LD1117V50C is supplied in SOT-223 package (TO-261AA), with exposed thermal pad electrically connected to V_OUT. The package supports surface-mount reflow and provides optimized thermal performance for high-current LDO applications in compact designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM1117-5.0 and MIC5205-5.0, LD1117V50C uniquely balances high current (800 mA), low dropout (1.1 V), tight tolerance (±1 %), and strong PSRR (75 dB) in a thermally capable SOT-223 package - making it optimal for industrial and automotive post-regulation where both performance and reliability are non-negotiable.

Availability

LD1117V50C is available at Aetrix Electronics and suitable for industrial PLCs, USB-C power delivery sinks, embedded microcontroller core rails, and automotive body control modules requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LD1117V50C 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, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets with emphasis on power management and analog integration.

The LD1117 series belongs to ST's high-reliability linear regulator product line, engineered specifically for cost-sensitive industrial and automotive applications demanding robust thermal performance, tight output accuracy, and long-term supply stability.

FAQ

What is the minimum input voltage required for LD1117V50C to maintain regulation at 800 mA?

The LD1117V50C requires a minimum input voltage of 6.1 V to sustain 5.0 V output at 800 mA load, based on its maximum dropout voltage of 1.1 V at that current and temperature (–40 °C to +125 °C). At room temperature, dropout is typically 1.0 V, allowing operation from 6.0 V. Input below 6.0 V risks output collapse under full load.

Can LD1117V50C be used with ceramic output capacitors?

Yes - LD1117V50C is stable with ceramic capacitors as low as 10 µF, with no minimum ESR requirement. This eliminates the need for bulkier tantalum or aluminum electrolytic capacitors and supports compact, high-reliability designs. ST's datasheet explicitly validates ceramic use in Figures 3 and 4.

How does the thermal performance of SOT-223 compare to DPAK for LD1117V50C at 800 mA?

In SOT-223, R_thJA is 110 °C/W versus 100 °C/W for DPAK (TO-252). At 800 mA with 1.1 V dropout (0.88 W dissipation), SOT-223 yields ~97 °C rise above ambient - acceptable with moderate copper pour. DPAK reduces rise by ~9 °C but requires larger footprint; SOT-223 remains preferred for space-constrained boards where thermal margin is sufficient.

Is LD1117V50C qualified for automotive applications?

LD1117V50C is not AEC-Q100 qualified. The "C" suffix denotes extended temperature grade (–40 °C to +125 °C), but it lacks automotive-specific stress testing, failure analysis, and PPAP documentation. For automotive body control modules, ST recommends the AEC-Q100 qualified LD1117AV50 (same pinout, tighter initial tolerance) instead.