STMicroelectronics L5050STR

Overview

L5050STR from STMicroelectronics is a dual-output, electrically isolated 5 V low-dropout linear voltage regulator in SO-8 package, AEC-Q100 qualified for automotive use. It delivers 2×50 mA DC output current, maintains ±2% output voltage accuracy over −40 °C to +150 °C, and features two independent enable inputs (EN1/EN2), thermal shutdown, and short-circuit protection. Used in body control modules and ADAS domain controllers requiring redundant 5 V supplies.

For engineers reviewing the L5050STR datasheet, L5050STR pinout, L5050STR application, or L5050STR equivalent, key selection criteria include dual isolated 5 V outputs with independent enables, 500 mV max dropout at 100 mA pulsed, 5 µA quiescent current per channel when disabled, and SO-8 footprint compatibility with automotive thermal and reliability requirements.

Technical Context

The L5050STR implements two independent p-channel MOSFET-based LDO regulators in a single SO-8 package, each with dedicated input (VS1/VS2), ground (GND1/GND2), output (VO1/VO2), and enable (EN1/EN2) terminals. This architecture enables true electrical isolation between outputs-no shared internal reference or power path-supporting fault-tolerant dual-rail designs.

Each regulator uses a pre-trimmed 2.5 V bandgap reference and adaptive quiescent current control, reducing I_qn to 5 µA per channel when disabled and scaling up to 2.2 mA under full 100 mA pulsed load. Protection includes foldback current limiting, thermal shutdown at 150 °C (10 °C hysteresis), and robust ESD tolerance (±750 V CDM).

Key Specifications

Pinout & Package

Package: SO-8 (Small Outline, 8-pin), ECOPACK® compliant, tape-and-reel (TR) packaging. Thermal resistance R_thJA = 94 °C/W on 1-layer FR4 (77 mm × 86 mm, 2 cm² copper).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLE42744DV33 and TPS7B8750QKVURQ1, the L5050STR uniquely integrates two fully isolated 5 V LDOs with independent enables in one SO-8 package-reducing BOM count, PCB area, and inter-channel coupling risk in ASIL-B/C automotive systems.

Availability

L5050STR is available at Aetrix Electronics and suitable for automotive body control modules, ADAS domain controllers, infotainment head units, and electronic power steering systems requiring stable component supply with AEC-Q100 compliance and long-term production continuity.

Supply support for L5050STR 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 automotive, industrial, and power management ICs, with broad manufacturing scale and automotive-grade quality systems.

The L5050 series belongs to ST's automotive LDO portfolio, designed specifically for redundant, isolated 5 V regulation in harsh-environment vehicle electronics where functional safety and thermal resilience are mandatory.

FAQ

What is the maximum allowable pulsed output current per channel?

The L5050STR supports up to 100 mA pulsed current per channel (VO1 or VO2), with pulse duration constrained by thermal limits. At TJ = 125 °C, current limitation drops to ~170 mA (Figure 13); sustained 100 mA pulses require adequate PCB copper area (≥2 cm²) and ambient <85 °C to avoid thermal shutdown activation.

Can VS1 and VS2 be connected to the same input source?

Yes - VS1 and VS2 may be tied together for a common-input configuration (Figure 20), simplifying power routing. However, GND1 and GND2 must remain physically separate on the PCB to preserve electrical isolation between VO1 and VO2 outputs.

Is an external capacitor required on the EN pins?

No external capacitor is required on EN1 or EN2. The enable inputs have built-in hysteresis (800 mV) and leakage current <10 µA (Table 6). For noise immunity in high-EMI environments, a 100 pF capacitor to GND per EN pin is optional but not specified in the datasheet.

Does the L5050STR support reverse-battery protection?

No - the L5050STR lacks integrated reverse-polarity protection. External protection (e.g., series Schottky diode or ideal diode controller) is required if the application risks −12 V battery connection. Absolute maximum rating for VS is −0.3 V (Table 3), beyond which permanent damage may occur.