STMicroelectronics LDLN025J25R

Overview

LDLN025J25R from STMicroelectronics is a 250 mA ultra-low-noise low-dropout (LDO) voltage regulator in Flip-Chip4 package, delivering 2.5 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 circuits in portable electronics.

For engineers reviewing the LDLN025J25R datasheet, LDLN025J25R pinout, LDLN025J25R application, or LDLN025J25R 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 1 µF ceramic capacitors.

Technical Context

The LDLN025J25R employs a bandgap-referenced error amplifier with internal soft-start and thermal foldback protection. Its control loop is optimized for stability with low-ESR ceramic output capacitors (0.7–10 µF, ESR 5–500 mΩ), eliminating need for external compensation.

It integrates logic-controlled enable (VIH = 1.2 V, VIL = 0.4 V), output discharge (230 Ω internal pull-down), and controlled quiescent current regulation during dropout-ensuring predictable I_Q behavior from no-load to full 250 mA across –40 °C to +125 °C.

Key Specifications

Pinout & Package

LDLN025J25R is supplied in Flip-Chip4 package (0.41 mm height, 0.628 mm × 0.628 mm footprint), requiring solder-reflow assembly and 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 ultra-low-noise LDO applications.

Compared with XC6210B252MR-G, LDLN025J25R delivers 5.5 µV_RMS lower noise and 50 mV lower dropout-enabling tighter input voltage margins. Versus ADM7172ACPZ-2.5-R7, it trades 0.8 µV_RMS noise for +50 mA current capability and broader ceramic capacitor compatibility.

Availability

LDLN025J25R is available at Aetrix Electronics and suitable for smartphone RF modules, precision instrumentation, medical imaging sensors, and automotive camera systems requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LDLN025J25R 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, and analog/mixed-signal devices for industrial, automotive, 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 battery-constrained portable electronics-prioritizing PSRR, dropout, and quiescent current over raw speed or feature count.

FAQ

What is the minimum input voltage required for LDLN025J25R to maintain 2.5 V output at 250 mA?

The datasheet specifies a maximum dropout voltage of 250 mV at 250 mA for the Flip-Chip4 package. Therefore, the minimum input voltage is 2.5 V + 0.25 V = 2.75 V. Operation below this will cause output voltage collapse or regulation loss, confirmed across –40 °C to +125 °C per Table 4.

Can LDLN025J25R be used with 0.47 µF output capacitors?

No-ST specifies a minimum output capacitance of 0.7 µF (Table 5). Using 0.47 µF violates the stability region defined in Figure 19 and risks oscillation or poor transient response, as verified in typical characteristics (Figures 24–26). Always use ≥0.7 µF X7R/X5R ceramic with 5–500 mΩ ESR.

Does the NC pin on LDLN025J25R require PCB routing or grounding?

The NC pin (pin 4 in Flip-Chip4) is not internally connected. Per Table 1 and DS11756 page 3, it may be left floating or connected to GND for mechanical reinforcement-but it carries no electrical function and must not be tied to any active signal or voltage rail.

How does the thermal shutdown behave during sustained overload?

Thermal shutdown activates at TJ = 160 °C with 20 °C hysteresis (Table 4). During sustained overload, the device cycles between regulation and shutdown-limiting average power dissipation. Recovery occurs only after junction cools below 140 °C, preventing damage but causing output voltage interruption until thermal equilibrium is restored.