STMicroelectronics LD56100DPU18R

Overview

LD56100DPU18R from STMicroelectronics is a 1 A ultra-low-noise, low-dropout linear voltage regulator with 1.8 V fixed output, 120 mV typical dropout at 1 A/3.3 V, ±1% output accuracy over -40 °C to +85 °C, and 13 µV_RMS noise (10 Hz–100 kHz). It operates from 1.8–5.5 V input and targets precision power rails in camera modules and mobile baseband processors.

For engineers reviewing the LD56100DPU18R datasheet, LD56100DPU18R pinout, LD56100DPU18R application, or LD56100DPU18R equivalent, key selection criteria include its DFN8 (1.2 × 1.6 mm) footprint, logic-controlled shutdown (<0.1 µA standby), internal soft-start, and optional output discharge-critical for battery-powered systems requiring fast transient response and ultra-low EMI.

Technical Context

The LD56100DPU18R implements a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout and high PSRR (70 dB @ 1 kHz). Its feedback loop is internally compensated for stability with ≥1 µF ceramic output capacitors (X5R/X7R).

It integrates dual protection architecture: current-limit foldback (1.1–1.6 A active mode; 0.4 A short-circuit) controlled by LCON pin logic level, and thermal shutdown at 170 °C with 20 °C hysteresis. The EN pin provides TTL/CMOS-compatible enable control with <400 nA input current.

Key Specifications

Pinout & Package

LD56100DPU18R is housed in a thermally enhanced DFN8 package (1.2 mm × 1.6 mm, 0.4 mm pitch), with exposed thermal pad connected to PCB ground for efficient heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B182MR-G and ADP160ACBZ-1.8-R7, LD56100DPU18R delivers 1 A at 120 mV dropout and 13 µV_RMS noise in a 1.2 × 1.6 mm DFN8 - making it uniquely suited for space-constrained, high-performance mobile imaging and connectivity applications where noise, size, and current capability are co-critical.

Availability

LD56100DPU18R is available at Aetrix Electronics and suitable for mobile camera modules, smartphone baseband processors, and wearable health sensor hubs requiring stable component supply across production lifecycles.

Supply support for LD56100DPU18R 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 LD56100 series belongs to ST's high-accuracy, ultra-low-noise LDO portfolio, engineered specifically for battery-powered portable electronics demanding minimal dropout, sub-µA quiescent current, and exceptional PSRR in sub-2 mm² packages.

FAQ

What is the minimum recommended output capacitor value and dielectric type?

The LD56100DPU18R requires a minimum 1 µF ceramic output capacitor. X5R or X7R dielectrics are explicitly recommended due to their stable capacitance and ESR across temperature (-40 °C to +125 °C) and bias voltage, ensuring loop stability and transient performance. NP0/C0G is acceptable but not optimal for ESR-related damping.

How does the LCON pin affect current limiting and thermal behavior?

When LCON is tied to VIN or left floating, the device limits output current to 1.1–1.6 A and short-circuit current to 400 mA. When pulled to GND, those limits reduce to 0.6–0.8 A and 180 mA respectively. This allows designers to trade peak current capability for lower thermal stress and safer operation with marginal PCB copper or smaller capacitors.

Is the output discharge feature enabled by default in LD56100DPU18R?

Yes. The "DPU" suffix in LD56100DPU18R indicates the version with integrated output discharge MOSFET (R_ON = 40 Ω). When EN is driven low, this MOSFET actively discharges the output capacitor to GND within milliseconds, eliminating residual voltage that could cause latch-up or improper power sequencing in multi-rail systems.

Can LD56100DPU18R operate with an input voltage below 1.8 V?

No. The absolute minimum operating input voltage is 1.8 V per datasheet Table 2. Operation below this violates the specified electrical characteristics and may result in unregulated output or loss of regulation. For sub-1.8 V inputs, a different regulator architecture (e.g., charge pump or buck-boost) is required.