STMicroelectronics LD39130SJ25R

Overview

LD39130SJ25R from STMicroelectronics is a 2.5 V fixed-output, 300 mA ultra-low-dropout linear regulator in Flip-chip 4-bump (0.69 × 0.69 mm, 0.4 mm pitch) package. It delivers ±1.0% output voltage accuracy at 25 °C, 300 mV typical dropout at 300 mA, and operates from 1.4 V to 5.5 V input. Its automatic green mode reduces quiescent current to 1 µA under light load, making it ideal for battery-powered digital still cameras and portable media players.

For engineers reviewing the LD39130SJ25R datasheet, LD39130SJ25R pinout, LD39130SJ25R application, or LD39130SJ25R equivalent, key selection criteria include dropout voltage at full load, green-mode quiescent current, thermal shutdown threshold (160 °C), output discharge resistance (100 Ω), and compatibility with 330 nF ceramic output capacitors.

Technical Context

The LD39130SJ25R integrates an auto-switching green/normal mode control logic that transitions between ultra-low-power operation (1 µA IQ) and fast-transient-response mode (45 µA IQ) based on load current thresholds (IGL = 1–2 mA, IGH = 10 mA). Its internal bandgap reference and error amplifier stabilize the 2.5 V output with <0.2 %/V line regulation in normal mode.

Unlike the DFN6 version, the LD39130SJ25R (Flip-chip CSP) omits the GM and ADJ pins - it operates exclusively in automatic green mode with no user disable option. The device includes internal soft-start (100 µs turn-on time), output discharge path (RON = 100 Ω), current foldback (50 mA short-circuit limit), and thermal shutdown (160 °C, 20 °C hysteresis).

Key Specifications

Pinout & Package

LD39130SJ25R uses the Flip-chip 4-bump package (0.69 × 0.69 mm, 0.4 mm pitch), optimized for minimal PCB footprint and thermal performance (R_thJA = 130 °C/W). This CSP variant has no GM or ADJ pins - only IN, GND, EN, and OUT terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B252MR-G and RT9013-25GB, the LD39130SJ25R uniquely combines ultra-small Flip-chip packaging, integrated output discharge, and precise green-mode transition thresholds - optimizing for space-constrained, battery-life-critical imaging systems.

Availability

LD39130SJ25R is available at Aetrix Electronics and suitable for digital still cameras, portable media players, and cordless phone handsets requiring stable component supply, long-term lifecycle support, and high-volume traceability.

Supply support for LD39130SJ25R 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 specializing in power management, analog, and microcontroller technologies for automotive, industrial, and consumer markets.

The LD39130S family targets ultra-low-power portable electronics, emphasizing minimal quiescent current, small-footprint packaging, and intelligent power-state adaptation for battery longevity.

FAQ

What is the minimum input voltage required for LD39130SJ25R to regulate 2.5 V output?

The LD39130SJ25R requires VIN ≥ VOUT + VDROP = 2.5 V + 0.3 V = 2.8 V to maintain regulation at 300 mA load. At lighter loads, dropout decreases - e.g., 150 mV at 100 mA - allowing operation down to 1.4 V input, though output will not be regulated below VIN − VDROP.

Does LD39130SJ25R require an external resistor divider for 2.5 V output?

No. LD39130SJ25R is a fixed-output variant; the "25" in the part number denotes 2.5 V. It does not include an ADJ pin and therefore requires no external resistors - unlike the adjustable LD39130S version which uses an ADJ pin and external divider.

Can LD39130SJ25R be used with a 100 nF output capacitor?

No. The datasheet specifies minimum COUT = 330 nF for stability, and recommends 1 µF for optimal transient response. A 100 nF capacitor falls outside the stable region defined in Figure 32 (Stability Plan vs. COUT/ESR) and may cause oscillation or poor load regulation.

How does the EN pin behave during power-down, and what happens to the output voltage?

When EN is pulled low, the LD39130SJ25R enters shutdown mode (<0.1 µA I_STANDBY) and activates its internal 100 Ω discharge MOSFET between OUT and GND, actively pulling the output voltage to near-zero within microseconds - preventing floating or slow decay that could disrupt downstream logic.