STMicroelectronics LDLN025J28R

Overview

LDLN025J28R from STMicroelectronics is a 250 mA ultra-low-noise low-dropout (LDO) voltage regulator in Flip-Chip4 package, delivering 2.8 V output with ±2% accuracy across line, load, and temperature. It operates from 1.5 V to 5.5 V input, achieves 250 mV dropout at 250 mA, and features 6.5 µV_RMS output noise and 80 dB PSRR at 100 Hz-optimized for powering noise-sensitive RF and analog circuits in portable devices.

For engineers reviewing the LDLN025J28R datasheet, LDLN025J28R pinout, LDLN025J28R application, or LDLN025J28R equivalent, this LDO is selected for battery-powered imaging sensors, VCO biasing, precision ADC references, and mobile RF modules where quiescent current (12 µA no-load), output discharge, and ceramic-capacitor stability are critical design requirements.

Technical Context

The LDLN025J28R employs a bandgap-referenced error amplifier with internal soft-start and controlled quiescent current regulation during dropout, enabling extended runtime in deep-discharge battery conditions. Its architecture integrates thermal shutdown (160 °C trip), overcurrent limiting (~250–500 mA), and logic-controlled enable with internal 1 MΩ pulldown.

Stability is guaranteed with 1 µF ceramic input/output capacitors (ESR 5–500 mΩ); the device does not require external compensation. The output discharge feature actively pulls VOUT to GND when EN is low, preventing floating rail issues in power-sequenced systems.

Key Specifications

Pinout & Package

LDLN025J28R is packaged in Flip-Chip4 (0.41 mm × 0.63 mm, 0.25 mm height), a bottom-terminated die-scale package requiring soldered exposed pad connection to GND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B282MR-G and ADP160AUJZ-2.8-R7, LDLN025J28R delivers superior noise/PSRR performance, full 250 mA capability, and integrated discharge-making it the only choice for RF-sensitive, high-accuracy, and battery-constrained designs requiring guaranteed sub-µA shutdown.

Availability

LDLN025J28R is available at Aetrix Electronics and suitable for smartphone camera modules, VCO power supplies, portable medical sensors, and industrial IoT nodes requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LDLN025J28R 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The LDLN025 series belongs to ST's ultra-low-noise LDO product line, engineered specifically for powering noise-critical analog and RF circuitry in space-constrained, battery-operated portable electronics.

FAQ

What is the minimum input voltage required for LDLN025J28R to regulate 2.8 V output?

The LDLN025J28R requires VIN ≥ VOUT + 1 V (i.e., ≥3.8 V) for guaranteed specifications per datasheet test conditions-but it remains functional down to 1.5 V input. At VIN = 3.0 V, dropout is 200 mV (typical), so regulation holds with 2.8 V output as long as VIN stays above 3.0 V. Below that, output drops linearly.

Can LDLN025J28R be used with 0.47 µF output capacitors?

No-0.47 µF is below the minimum recommended 0.7 µF output capacitance. Using 0.47 µF risks instability and degraded transient response, especially under load steps. The datasheet specifies 0.7–10 µF ceramic capacitors with 5–500 mΩ ESR; 1 µF is the validated value for all performance curves.

Does the NC pin on LDLN025J28R require PCB routing or grounding?

The NC pin is not internally connected and has no electrical function. It may be left unconnected or tied to GND for mechanical reinforcement during reflow. No PCB trace routing is required, and connecting it to GND does not affect electrical performance or thermal behavior.

How does the output discharge feature behave during fast enable/disable cycling?

The internal 230 Ω discharge path activates within 1 µs of EN falling below V_IL, pulling VOUT to GND in <10 µs for 1 µF load. During rapid toggling (>10 kHz), residual charge may cause brief voltage rebound, but the device maintains safe discharge behavior across its full -40 °C to +125 °C operating range per characterization data.