STMicroelectronics LDLN025J50R

Overview

LDLN025J50R from STMicroelectronics is a 250 mA ultra-low-noise low-dropout linear regulator in Flip-Chip4 package, delivering 5.0 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 full 250 mA load (Flip-Chip4), and features 6.5 µV_RMS output noise (10 Hz–100 kHz) and 80 dB PSRR at 100 Hz-enabling clean power for RF VCOs and high-resolution ADCs in space-constrained mobile modules.

For engineers reviewing the LDLN025J50R datasheet, LDLN025J50R pinout, LDLN025J50R application, or LDLN025J50R equivalent, this LDO is selected for battery-powered instrumentation requiring sub-12 µA quiescent current, logic-controlled shutdown (<1 µA off-state), and ceramic-capacitor stability without external compensation.

Technical Context

The LDLN025J50R employs a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout and controlled quiescent current during dropout operation. Its internal soft-start and output discharge circuitry prevent inrush spikes and ensure safe power sequencing in multi-rail systems.

Designed for noise-sensitive analog/RF loads, it integrates thermal shutdown (160 °C trip, 20 °C hysteresis) and foldback current limiting (250–500 mA short-circuit current). The enable input features internal 1 MΩ pull-down and logic thresholds of V_IL ≤ 0.4 V / V_IH ≥ 1.2 V, compatible with 1.8 V and 3.3 V GPIOs.

Key Specifications

Pinout & Package

LDLN025J50R is packaged in Flip-Chip4 (0.628 mm × 0.628 mm, 0.410 mm height), a bottom-terminated die-scale package requiring solder paste stencil and reflow-compatible PCB layout per Figure 31 in DS11756 Rev 8.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B502MR-G, LDLN025J50R adds output discharge and thermal protection critical for unattended embedded systems; versus ADM7172ACPZ-5.0-R7, it delivers optimal cost, size, and feature balance for 250 mA mobile/industrial LDO needs without over-engineering.

Availability

LDLN025J50R is available at Aetrix Electronics and suitable for smartphone RF modules, imaging sensor bias supplies, portable instrumentation front-ends, and industrial IoT wireless nodes requiring stable component supply with guaranteed long-term sourcing.

Supply support for LDLN025J50R 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 microcontrollers, power management ICs, sensors, and analog components for automotive, industrial, and consumer markets.

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

FAQ

What is the maximum allowable input voltage for LDLN025J50R?

The absolute maximum input voltage is 7 V, but the recommended operating range is 1.5 V to 5.5 V. Exceeding 5.5 V risks violating the V_OUT + 0.3 V limit (5.3 V max at 5.0 V output) and may trigger internal protection or degrade long-term reliability. Operation above 5.5 V is not characterized or guaranteed per DS11756 Rev 8.

Can LDLN025J50R be used with 0.47 µF output capacitors?

No-DS11756 specifies minimum C_OUT as 0.7 µF for stability. Using 0.47 µF violates the stability region defined in Figure 19 and risks oscillation under load transients, especially at high temperatures or low ESR. Always use ≥0.7 µF X7R ceramic with ESR between 5 mΩ and 500 mΩ.

Does the NC pin require PCB connection?

The NC pin (pin 4 in Flip-Chip4) is not internally connected and has no electrical function. ST recommends connecting it to GND for mechanical reinforcement and thermal dissipation, but it may be left floating if board layout constraints prohibit grounding. No performance impact occurs either way.

How does thermal shutdown behave during continuous overload?

Thermal shutdown activates at T_J = 160 °C with 20 °C hysteresis, forcing the LDO into high-impedance state until junction temperature falls below 140 °C. During sustained overload, this results in intermittent regulation (hiccup mode), limiting average power dissipation and preventing permanent damage per Table 4 and Section 5 of DS11756 Rev 8.