STMicroelectronics LD39130SJ12R

Overview

LD39130SJ12R from STMicroelectronics is a 300 mA ultra-low-quiescent-current linear voltage regulator with fixed 1.2 V output, 300 mV typical dropout at full load, ±1.0% output accuracy at 25 °C, and automatic green mode for battery-powered systems. It operates from 1.4 V to 5.5 V input and delivers stable power to low-power microcontrollers and RF subsystems in portable media players.

For engineers reviewing the LD39130SJ12R datasheet, LD39130SJ12R pinout, LD39130SJ12R application, or LD39130SJ12R equivalent, key selection criteria include its 1 µA green-mode quiescent current, 100 nA enable pin leakage, internal soft-start, output discharge path, and compatibility with 330 nF ceramic output capacitors.

Technical Context

The LD39130SJ12R integrates a bandgap reference, fast-turn-on op-amp control loop, and auto-switching logic between green mode (ultra-low IQ) and normal mode (fast transient response). Its green mode activation threshold is 1–2 mA load current, and deactivation occurs at ~10 mA.

It features internal current foldback limiting (50 mA short-circuit current), thermal shutdown at 160 °C with 20 °C hysteresis, and an integrated 100 Ω output discharge MOSFET activated during shutdown. The device uses a Flip-chip 4-bump 0.69 × 0.69 mm package with 0.4 mm pitch and no GM or ADJ pins-unlike the DFN6 version.

Key Specifications

Pinout & Package

LD39130SJ12R is housed in a 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). Unlike the DFN6 variant, this CSP version omits GM and ADJ pins and operates exclusively in automatic green mode.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with XC6210B122MR-G and RT9080-12GSP, LD39130SJ12R uniquely combines sub-1-µA green-mode IQ, built-in output discharge, and 300 mV dropout in a 0.69 mm² CSP-enabling smaller, longer-life, and more robust battery-powered designs without external support components.

Availability

LD39130SJ12R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, cordless phones, and portable media players requiring stable component supply with long-term lifecycle assurance.

Supply support for LD39130SJ12R 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, microcontrollers, and analog ICs, with manufacturing aligned to ISO 9001 and IATF 16949 standards.

The LD39130S family targets ultra-low-power portable electronics, delivering high-accuracy regulation with adaptive IQ scaling to maximize battery runtime in space-constrained devices.

FAQ

What is the minimum input voltage required for LD39130SJ12R to maintain 1.2 V output at 300 mA?

The minimum input is 1.5 V: with 300 mV typical dropout at full load, VIN must be ≥ VOUT + VDROP = 1.2 V + 0.3 V = 1.5 V. Absolute minimum specified is 1.4 V, but regulation margin drops below 1.5 V under worst-case conditions including temperature and tolerance.

Does LD39130SJ12R require an external resistor divider for output setting?

No. LD39130SJ12R is a fixed-output variant (1.2 V); it has no ADJ pin and does not support adjustable output. The ADJ pin exists only on the DFN6-packaged LD39130S versions-not on the Flip-chip LD39130SJ series.

Can LD39130SJ12R 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 step recovery.

Is the green mode function user-controllable on LD39130SJ12R?

No. The LD39130SJ (Flip-chip) version operates exclusively in automatic green mode-there is no GM pin. Unlike the DFN6 variant, it cannot be forced into permanent normal mode; switching between modes is fully internal and load-triggered.