STMicroelectronics LDLN025J33R

Overview

LDLN025J33R from STMicroelectronics is a 250 mA ultra-low-noise low-dropout (LDO) voltage regulator in Flip-Chip4 package, delivering 3.3 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, and features 6.5 µV_RMS output noise (10 Hz–100 kHz) and 80 dB PSRR at 100 Hz-optimized for powering noise-sensitive RF and analog circuitry in portable devices.

For engineers reviewing the LDLN025J33R datasheet, LDLN025J33R pinout, LDLN025J33R application, or LDLN025J33R equivalent, this LDO is selected for battery-powered systems requiring extended standby life (12 µA quiescent current), clean power for VCOs/ADCs, logic-controlled shutdown (<1 µA off-state), and stable operation with ceramic capacitors.

Technical Context

The LDLN025J33R uses a bandgap-referenced error amplifier and PMOS pass transistor to maintain tight output regulation under varying load (1 mA–250 mA) and input (1.5 V–5.5 V) conditions. Its internal soft-start limits inrush current, while thermal shutdown (160 °C) and foldback overcurrent protection ensure robustness during fault conditions.

Designed for high-PSRR and ultra-low-noise performance, it integrates an output discharge path (230 Ω) and controlled quiescent current behavior in dropout-enabling reliable operation in deep battery discharge scenarios without compromising noise or efficiency.

Key Specifications

Pinout & Package

LDLN025J33R is packaged in Flip-Chip4 (0.41 mm × 0.41 mm, 0.25 mm height), a bottom-terminated die-scale package requiring solder paste stencil optimization and X-ray inspection for assembly validation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B332MR-G and ADP160AUJZ-3.3-R7, LDLN025J33R uniquely combines 250 mA capability, 6.5 µV_RMS noise, and Flip-Chip4 size-making it the only option for space-constrained, high-current, ultra-low-noise mobile RF applications.

Availability

LDLN025J33R is available at Aetrix Electronics and suitable for mobile RF modules, high-speed image sensors, precision ADC reference supplies, and always-on IoT sensor nodes requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LDLN025J33R 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, analog chips, and MEMS sensors for automotive, industrial, and consumer markets.

LDLN025J33R belongs to ST's ultra-low-noise LDO family, engineered specifically for noise-critical analog and RF subsystems in battery-powered portable electronics-prioritizing PSRR, output cleanliness, and quiescent current control over raw efficiency.

FAQ

What is the minimum input voltage required for LDLN025J33R to regulate 3.3 V at 250 mA?

The minimum input voltage is 3.55 V, calculated as V_OUT + V_DROP = 3.3 V + 0.25 V. This assumes worst-case 250 mV dropout at 250 mA and –40 °C to +125 °C operation in Flip-Chip4 package, per Table 4 of DS11756 Rev 8.

Can LDLN025J33R be used with a 1 µF output capacitor only?

Yes-1 µF X7R ceramic is explicitly recommended in Table 5 and validated across the stability region (Figure 19). The device remains stable with ESR between 5 mΩ and 500 mΩ, eliminating need for series resistance or larger capacitance.

Does the NC pin on LDLN025J33R require PCB connection?

No-the NC pin is not internally connected and may be left unconnected or tied to GND for mechanical anchoring. Per Table 1, it serves no electrical function and has no impact on thermal or electrical performance when floating.

How does LDLN025J33R behave during input voltage dropout?

It maintains controlled quiescent current (≤425 µA at 250 mA load, –40 °C to +125 °C) and continues regulation until VIN drops below V_OUT + V_DROP. Unlike conventional LDOs, its I_Q does not spike unpredictably, preserving battery energy during brownout conditions.