STMicroelectronics LD39015J25R

Overview

LD39015J25R from STMicroelectronics is a 150 mA ultra-low-noise, low-quiescent-current LDO voltage regulator with 2.5 V fixed output, 90 mV typical dropout at 100 mA, ±2.0% output accuracy at 25 °C, and stable operation with 1 µF ceramic output capacitor. It operates from 1.5 V to 5.5 V input and features logic-controlled shutdown (EN pin), enabling <1 µA off-mode current - ideal for battery-powered portable electronics requiring clean, efficient power delivery.

For engineers reviewing the LD39015J25R datasheet, LD39015J25R pinout, LD39015J25R application, or LD39015J25R equivalent, key selection criteria include dropout voltage under load, noise performance in sensitive analog/RF sections, quiescent current across temperature, EN logic thresholds, and compatibility with miniature flip-chip packaging in space-constrained designs.

Technical Context

The LD39015J25R uses a bandgap-referenced feedback loop with internal trimming to maintain tight output regulation across -40 °C to +125 °C junction temperature. Its flip-chip architecture minimizes parasitic inductance, supporting fast transient response and high PSRR (74 dB at 1 kHz) without external compensation.

Enable control is TTL- and CMOS-compatible: EN < 0.4 V forces shutdown (<1 µA I_Q), while EN > 0.9 V enables regulation. Internal thermal and short-circuit protection operate autonomously without external circuitry, limiting output current to ~200 mA and shutting down above 160 °C with 20 °C hysteresis.

Key Specifications

Pinout & Package

LD39015J25R uses a Flip-chip 4-bump package (1.1 × 1.1 mm, 0.65 mm typical height), optimized for minimal PCB footprint and thermal resistance (R_thJA = 180 °C/W). No external heatsink required for ≤150 mA loads at ambient ≤85 °C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B25MR-G and BD39015FVM-C, LD39015J25R offers the smallest footprint (1.1 × 1.1 mm), lowest dropout (90 mV), and lowest noise (54 µV_RMS) - making it optimal for miniaturized, battery-critical, and noise-sensitive applications where board area and efficiency are constrained.

Availability

LD39015J25R is available at Aetrix Electronics and suitable for wearable health sensors, Bluetooth Low Energy modules, and industrial wireless sensor nodes requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for LD39015J25R 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 industrial, automotive, and consumer markets.

LD39015J25R belongs to ST's LD39xx ultra-low-noise LDO family, engineered specifically for space-constrained, battery-powered portable electronics demanding high PSRR, sub-µA shutdown, and ceramic-capacitor stability.

FAQ

Is LD39015J25R compatible with 1 µF ceramic output capacitors?

Yes - the LD39015J25R is explicitly designed and characterized for stability with 1 µF ceramic capacitors (X5R/X7R), as confirmed in Table 5 and Figure 7 of the datasheet. This eliminates the need for larger or more expensive capacitor types and simplifies layout in compact designs.

What is the maximum input voltage the LD39015J25R can tolerate?

The absolute maximum DC input voltage is 6 V (per Table 3), but the recommended operating range is 1.5 V to 5.5 V. Exceeding 5.5 V risks violating safe operating area limits and may trigger internal protection or cause premature wear, even if not immediately destructive.

Does LD39015J25R require an input capacitor?

Yes - a minimum 1 µF ceramic input capacitor is required for stability and transient suppression, as specified in the Typical Application circuit (Figure 3) and Section 3 of the datasheet. Omitting it may cause oscillation or excessive line-transient overshoot during load changes.

How does the EN pin behave over temperature?

The EN pin logic thresholds are specified across -40 °C to +125 °C: V_EN(L) ≤ 0.4 V (max) and V_EN(H) ≥ 0.9 V (min). This guarantees reliable shutdown and activation across full automotive and industrial temperature ranges without external level-shifting.