STMicroelectronics LDL212PU50R

Overview

LDL212PU50R from STMicroelectronics is a high-PSRR, low-dropout linear regulator IC delivering 1.2 A output current with 350 mV typical dropout at full load, fixed 5.0 V output, and input voltage range of 2.5 V to 18 V. It features undervoltage lockout, enable control, thermal/current/power protection, and operates from –40 °C to 125 °C - used in DC-DC post-regulation and SMPS secondary-side filtering.

For engineers reviewing the LDL212PU50R datasheet, LDL212PU50R pinout, LDL212PU50R application, or LDL212PU50R equivalent, this device is selected for stable point-of-load regulation where high PSRR (87 dB @ 120 Hz), tight output accuracy (±2% at 25 °C), and low quiescent current (250–380 µA) are critical in industrial and consumer power rails.

Technical Context

The LDL212PU50R implements a bandgap-referenced op-amp control loop with internal bias generator and RC-filtered feedback path. Its architecture supports both fixed-output (5.0 V) and adjustable configurations via dedicated SENSE/ADJ pin functionality.

It integrates UVLO with 2.4 V turn-on threshold and 200 mV hysteresis, logic-level enable (VEN low = shutdown, <0.4 V), and thermal shutdown at 175 °C with 25 °C hysteresis. Protection includes foldback current limiting and SOA-based power limitation.

Key Specifications

Pinout & Package

LDL212PU50R is available in SO-8 batwing plastic micropackage and DFN6 (3x3) packages. Pin functions are identical across variants; exposed pad must be connected to GND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with TSDR212PU50R, LDL212PU50R trades automotive qualification for broader commercial availability and lower unit cost; versus LDL112PU50R, it delivers 2.4× higher output current and 15 dB better PSRR - critical for noise-sensitive, high-current loads.

Availability

LDL212PU50R is available at Aetrix Electronics and suitable for industrial motor control, smart energy metering, automotive infotainment, and programmable logic controller applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LDL212PU50R 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The LDL212 belongs to ST's high-PSRR, low-dropout linear regulator product line, engineered specifically for post-regulation in switched-mode power supplies and noise-critical analog subsystems in harsh thermal environments.

FAQ

What is the minimum input voltage required for stable 5.0 V output at 1.2 A?

The LDL212PU50R requires VIN ≥ VOUT + VDROP(MAX). With 700 mV maximum dropout (SO-8 package, full temperature range), minimum input is 5.7 V. At 25 °C and typical 350 mV dropout, 5.35 V suffices. Input below 5.3 V risks dropout and output collapse under full load.

Can LDL212PU50R be used with ceramic output capacitors only?

Yes - the device is stable with 4.7 µF ceramic output capacitors having ESR ≥ 0.01 Ω (per Figure 30). ST specifies stability with X5R/X7R types; no tantalum or electrolytic capacitor is required, reducing board area and improving reliability.

How does the SENSE pin function in the fixed-output LDL212PU50R?

In fixed-output versions like LDL212PU50R, the SENSE pin must be shorted to VOUT. This configures the internal feedback divider for 5.0 V regulation. Leaving it floating or connecting to another node invalidates output accuracy and may cause instability or overvoltage.

Is thermal derating required for continuous 1.2 A operation in SO-8 package?

Yes - SO-8 has θ_JA = 55 °C/W. At 1.2 A with 350 mV dropout (0.42 W dissipation), ambient must stay ≤ 85 °C to keep junction ≤ 125 °C. For full-load operation above 85 °C ambient, use DFN6 (3x3) (θ_JA = 55 °C/W) or add copper pour and airflow.