STMicroelectronics LD39030SJ15R

Overview

LD39030SJ15R from STMicroelectronics is a 300 mA low-noise, low-quiescent-current LDO voltage regulator with fixed 1.5 V output, 200 mV typical dropout at full load, ±2.0% output accuracy at 25 °C, and operation from 1.5 V to 5.5 V input. It integrates logic-controlled shutdown, internal soft-start (100 μs), thermal/short-circuit protection, and supports 1 μF ceramic output capacitance - deployed in battery-powered portable electronics requiring stable, quiet power for RF or analog circuitry.

For engineers reviewing the LD39030SJ15R datasheet, LD39030SJ15R pinout, LD39030SJ15R application, or LD39030SJ15R equivalent, key selection criteria include ultra-low IQ (20 μA typ. no-load), 30 μVRMS noise (1–100 kHz), flip-chip 4-bump package footprint, enable threshold compatibility with 1.5 V logic, and guaranteed 300 mA output across –40 °C to 125 °C junction temperature.

Technical Context

The LD39030SJ15R uses a bandgap reference trimmed to 1.22 V and a PMOS pass transistor architecture enabling ultra-low dropout and high PSRR (62 dB @ 1 kHz). Its internal soft-start limits inrush current without external components, and the enable pin provides precise logic-level control (VEN low = shutdown, <0.4 V; high = active, >0.9 V).

Stability is ensured with ≥1 μF ceramic COUT and ESR <2 Ω at 100 kHz; it delivers 30 μVRMS output noise over 1–100 kHz and maintains static line regulation of 0.01 %/V and load regulation of 0.002 %/mA - critical for powering noise-sensitive ADCs, PLLs, and RF front-ends in compact portable systems.

Key Specifications

Pinout & Package

LD39030SJ15R uses a flip-chip 4-bump package (0.8 mm × 0.8 mm, 0.4 mm pitch), optimized for minimal PCB area and thermal performance (R_thJA = 180 °C/W). The bump layout matches standard 4-pad SMD footprints with solder mask defined pads per Figure 23 in DocID18103 Rev 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B152MR-G and RT9013-15GB, LD39030SJ15R uniquely combines 200 mV dropout, 30 μVRMS noise, 100 μs soft-start, and 125 °C junction rating in a 0.8×0.8 mm flip-chip package - delivering superior thermal headroom, lower system noise, and smaller total solution size for high-density portable designs.

Availability

LD39030SJ15R is available at Aetrix Electronics and suitable for mobile phone baseband power, digital still camera sensor biasing, cordless phone RF transceiver supply, and PDA application processor core regulation requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for LD39030SJ15R 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, sensors, and analog devices for industrial, automotive, and consumer markets.

LD39030SJ15R belongs to ST's LD39030 series of ultra-low-noise, low-IQ LDOs engineered specifically for battery-powered portable electronics where efficiency, noise immunity, and miniaturization are critical design drivers.

FAQ

What is the minimum input voltage required for LD39030SJ15R to maintain 1.5 V output at 300 mA?

The LD39030SJ15R requires VIN ≥ 1.7 V to sustain 1.5 V output at 300 mA, based on its typical 200 mV dropout voltage (1.5 V + 0.2 V = 1.7 V). At –40 °C to 125 °C, maximum dropout rises to 300 mV, so VIN ≥ 1.8 V is recommended for full-temperature guarantee. Input below 1.5 V is prohibited per absolute maximum ratings.

Can LD39030SJ15R operate stably with a 1 μF X5R ceramic capacitor on the output?

Yes - LD39030SJ15R is explicitly characterized and guaranteed stable with 1 μF X5R/X7R ceramic capacitors having ESR ≤ 2 Ω at 100 kHz. The device's internal compensation eliminates need for series resistance or larger capacitance, reducing BOM count and PCB area versus older LDO architectures.

How does the enable pin behave during power-up, and what logic levels activate the device?

The EN pin is active-high with guaranteed thresholds: device enables when VEN > 0.9 V (typ.) and shuts down when VEN < 0.4 V (max.). Input leakage is 0.1–100 nA, allowing direct connection to GPIOs without pull-up resistors. Turn-on time is 100 μs from EN crossing 0.9 V to VOUT reaching 95% of 1.5 V.

Is LD39030SJ15R qualified for automotive applications?

No - LD39030SJ15R is not AEC-Q100 qualified and is explicitly excluded from safety-critical, automotive, or aerospace use per ST's disclaimer. Its –40 °C to 125 °C junction rating supports industrial and portable consumer applications, but it lacks automotive-grade screening, qualification testing, or PPAP documentation.