STMicroelectronics LDL112PU12R

Overview

LDL112PU12R from STMicroelectronics is a 1.2 A low-dropout linear regulator with fixed 1.2 V output, 300 mV typical dropout at 1 A, ±2.0% output voltage accuracy at 25 °C, reverse current protection, and logic-controlled shutdown. It operates from 1.6–5.5 V input and supports battery-powered USB devices requiring stable low-voltage point-of-load regulation.

For engineers reviewing the LDL112PU12R datasheet, LDL112PU12R pinout, LDL112PU12R application, or LDL112PU12R equivalent, key selection criteria include dropout voltage under 1.2 A load, quiescent current below 35 µA at no load, thermal shutdown at 165 °C, compatibility with 1 µF ceramic output capacitors, and EN pin logic thresholds for low-power system control.

Technical Context

The LDL112PU12R uses a PMOS pass transistor architecture enabling true reverse current blocking and ultra-low dropout. Its internal bandgap reference (800 mV) feeds an error amplifier that regulates output via feedback to the gate of the PMOS device, supporting both fixed-output and adjustable versions.

It integrates thermal shutdown with 20 °C hysteresis and current limiting (~2 A short-circuit current), and features an enable input with logic-compatible thresholds (V_IL ≤ 0.35 V, V_IH ≥ 1.4 V) referenced to VIN across –40 °C to 125 °C junction temperature range.

Key Specifications

Pinout & Package

LDL112PU12R is packaged in DFN6 (2x2 mm) with exposed thermal pad, optimized for space-constrained portable designs. The package requires GND connection of the exposed pad for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1012-1.2TR and AP7361-12YG-13, LDL112PU12R delivers superior efficiency (300 mV dropout), lower quiescent current (35 µA), and integrated reverse current blocking - making it optimal for battery longevity and system-level fault resilience in compact designs.

Availability

LDL112PU12R is available at Aetrix Electronics and suitable for wearable health monitors, USB-C peripheral hubs, and industrial sensor nodes requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for LDL112PU12R 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 analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The LDL112 series belongs to ST's high-efficiency LDO portfolio, engineered specifically for ultra-low-power battery-operated systems demanding reverse current blocking, ceramic-capacitor stability, and extended temperature operation.

FAQ

What is the minimum input voltage required for LDL112PU12R to maintain regulation at 1.2 A load?

The minimum input voltage is determined by dropout: VIN(min) = VOUT + VDROP = 1.2 V + 0.6 V = 1.8 V (max dropout at 1.2 A and full temperature range). At 25 °C and 1 A, 1.5 V input suffices. Operation below 1.6 V is outside absolute maximum ratings and not functional.

Can LDL112PU12R be used with a 10 µF aluminum electrolytic output capacitor instead of ceramic?

No - the LDL112PU12R is compensated for ceramic capacitors with ESR < 10 mΩ. Aluminum electrolytics have higher ESR (typically 50–200 mΩ) and capacitance drift, risking instability and overshoot. Only 1–10 µF X5R/X7R ceramics are validated per DS10321 Section 7.2.

Does the EN pin require a pull-up resistor when driven by an open-drain GPIO?

Yes - because EN is active-high and has no internal pull-up, an external 10–100 kΩ pull-up to VIN is required when interfaced with open-drain or tri-state drivers. Leaving EN floating risks undefined operation and potential shoot-through or excessive quiescent current.

Is the exposed pad on the DFN6 (2x2) package electrically connected to GND internally?

Yes - the exposed pad is internally tied to GND and serves as the primary thermal and electrical return path. Per DS10321 Table 8 and Figure 35, it must be soldered to a dedicated GND copper area ≥ 25 mm² with ≥4 thermal vias (0.3 mm diameter) to meet R_thJA = 65 °C/W and prevent thermal shutdown under 1.2 A load.