STMicroelectronics LDLN025M15R

Overview

LDLN025M15R from STMicroelectronics is a 250 mA ultra-low-noise low-dropout linear regulator in SOT23-5L package, delivering 1.5 V output with ±2% accuracy across -40 °C to +125 °C, 12 μA quiescent current at no-load, 250 mV dropout at full load, and 6.5 μVRMS output noise (10 Hz–100 kHz). It powers noise-sensitive analog circuitry in battery-constrained portable systems.

For engineers reviewing the LDLN025M15R datasheet, LDLN025M15R pinout, LDLN025M15R application, or LDLN025M15R equivalent, this page delivers verified electrical specs, validated package mapping, confirmed thermal and PSRR performance, and real-world use context for RF, imaging, and precision analog subsystems.

Technical Context

The LDLN025M15R employs a bandgap-referenced error amplifier with internal soft-start and logic-controlled enable, supporting fast turn-on (80–150 μs) and sub-1 μA shutdown current. Its bias generator maintains stable quiescent current control even in dropout, extending runtime in deep-battery scenarios.

Designed for ceramic-capacitor stability, it achieves 80 dB PSRR at 100 Hz and 60 dB at 100 kHz while rejecting supply ripple across VCO bias rails, ADC reference paths, and image sensor analog front-ends-without requiring external compensation.

Key Specifications

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 2.95 mm × 1.60 mm × 1.45 mm body, exposed pad for thermal enhancement (must be connected to GND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise LDO applications.

Compared with XC6210B152MR and ADP125ARHZ-1.5-R7, the LDLN025M15R uniquely balances 250 mA drive, 6.5 μVRMS noise, integrated discharge, and SOT23-5L compactness-making it optimal for space-constrained, ultra-low-phase-noise RF and imaging subsystems.

Availability

LDLN025M15R is available at Aetrix Electronics and suitable for smartphone camera modules, portable instrumentation ADCs, VCO bias supplies, and RF front-end LNA bias circuits requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LDLN025M15R 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 power management, analog, MEMS, and microcontrollers, with manufacturing facilities across Europe, Asia, and the Americas.

The LDLN025 series belongs to ST's ultra-low-noise LDO product line, engineered specifically for noise-critical analog and RF subsystems in portable and automotive electronics where PSRR, dropout, and quiescent current are design-critical.

FAQ

What is the minimum input voltage required for LDLN025M15R to regulate at 1.5 V?

The LDLN025M15R requires VIN ≥ VOUT + dropout voltage. At 250 mA load and +25 °C, typical dropout is 120 mV, so minimum VIN is 1.62 V. Over temperature and process variation, worst-case dropout reaches 250 mV, requiring VIN ≥ 1.75 V for guaranteed regulation across -40 °C to +125 °C.

Can LDLN025M15R be used with 0.47 μF output capacitors?

No. The datasheet specifies minimum COUT = 0.7 μF for stability across all operating conditions. Using 0.47 μF risks oscillation or poor transient response, especially under load steps. Recommended values are 1 μF X7R ceramic with ESR ≤500 mΩ, placed within 2 mm of the VOUT and GND pins.

Does the NC pin on SOT23-5L require PCB connection?

Pin 4 in the SOT23-5L package is unconnected internally and may be left floating. However, ST recommends connecting it to GND for improved mechanical reliability and thermal conduction. It must never be tied to VIN or VOUT, as no internal isolation exists beyond physical separation.

How does the output discharge feature behave during enable toggling?

When EN transitions from high to low, the internal 230 Ω discharge path activates within 1 μs, discharging a 1 μF output capacitor from 1.5 V to <100 mV in ≈120 μs. Discharge stops immediately upon EN rising, and no discharge occurs during normal regulation or startup.