STMicroelectronics LDL112D18R

Overview

LDL112D18R from STMicroelectronics is a 1.2 A low-dropout linear regulator with fixed 1.8 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 ceramic output capacitors as small as 1 µF-ideal for USB-powered devices and battery-powered point-of-load regulation.

For engineers reviewing the LDL112D18R datasheet, LDL112D18R pinout, LDL112D18R application, or LDL112D18R equivalent, key selection criteria include dropout voltage under 1.2 A load, sub-1 µA shutdown current, thermal/short-circuit protection behavior, and compatibility with 1 µF ceramic COUT in space-constrained DFN6 (2x2) or SO8-batwing packages.

Technical Context

The LDL112D18R uses a PMOS pass transistor architecture enabling true reverse current blocking and ultra-low quiescent current (35 µA typ. at no load). Its internal bandgap reference (800 mV) and error amplifier regulate output via feedback to maintain ±2.0% accuracy across –40 °C to 125 °C junction temperature.

Enable logic control (EN pin) directly gates the internal bias network, reducing total supply current to ≤1 µA in off mode. Thermal shutdown triggers at 165 °C with 20 °C hysteresis, while current limiting caps short-circuit output at 1.4–2 A-both functions are fully internal and require no external components.

Key Specifications

Pinout & Package

LDL112D18R is available in SO8-batwing and DFN6 (2x2) mm packages. Both use identical 6-pin functional mapping: VIN, GND, EN, VOUT, NC, and exposed pad (connected to GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B182MR-G and AP2204K-18GN, LDL112D18R uniquely combines 1.2 A capability, 300 mV dropout at full load, reverse current blocking, and thermal shutdown in a single monolithic device-making it the only drop-in solution for compact, battery-critical 1.8 V systems demanding robustness and scalability.

Availability

LDL112D18R is available at Aetrix Electronics and suitable for USB-powered devices, battery-powered point-of-load regulation, and low-voltage microcontroller cores requiring stable component supply with long-term manufacturability.

Supply support for LDL112D18R 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 LDL112 series was developed specifically for ultra-low-power, high-reliability linear regulation in space- and energy-constrained applications-including wearables, IoT edge nodes, and automotive body electronics-where reverse current blocking and sub-1 µA shutdown are mandatory.

FAQ

What is the minimum input voltage required for LDL112D18R to maintain 1.8 V output at 1.2 A?

The minimum input voltage is determined by dropout: at 1.2 A, typical dropout is 350 mV (max 600 mV per datasheet Table 4). Thus, VIN must be ≥2.15 V (1.8 V + 350 mV) to guarantee regulation. For worst-case design, use 2.4 V (1.8 V + 600 mV) to accommodate temperature and process variation.

Can LDL112D18R be used with a 0.47 µF ceramic output capacitor?

No. The datasheet specifies a minimum of 1 µF ceramic capacitor for stability across all operating conditions (Section 7, Figure 25). Using 0.47 µF risks oscillation or poor transient response, especially under 1.2 A load steps. Always use ≥1 µF X5R/X7R ceramic with ESR <10 mΩ.

Does the exposed pad on the DFN6 (2x2) package require a dedicated thermal via array?

Yes. The exposed pad must be soldered to a solid GND plane with ≥4 thermal vias (0.3 mm diameter, spaced ≤1 mm apart) to achieve the specified R_thJA of 65 °C/W. Omitting vias raises junction temperature by >20 °C at 1.2 A, risking thermal shutdown in enclosed enclosures.

Is reverse current protection active when the EN pin is pulled low?

Yes. Reverse current blocking is inherent to the PMOS pass transistor architecture and remains fully active in shutdown mode (EN = GND). As confirmed in Section 6.3, the MOSFET gate and bulk are switched to VOUT, physically interrupting all conduction paths from VOUT to VIN-even when VOUT exceeds VIN by >100 mV.