STMicroelectronics LD39030SJ33R

Overview

LD39030SJ33R from STMicroelectronics is a 3.3 V, 300 mA low-noise LDO voltage regulator in a flip-chip 4-bump package (0.8 × 0.8 mm, 0.4 mm pitch), featuring 200 mV typical dropout at full load, 20 μA typical quiescent current at no load, and 30 μV_RMS output noise (1 kHz–100 kHz). It delivers stable regulation for battery-powered portable electronics requiring high PSRR (62 dB @ 1 kHz) and logic-controlled shutdown.

For engineers reviewing the LD39030SJ33R datasheet, LD39030SJ33R pinout, LD39030SJ33R application, or LD39030SJ33R equivalent, this page provides verified electrical specs, thermal behavior, soft-start timing, EN-controlled enable logic, and ceramic-capacitor compatibility - all critical for low-power wearable, imaging, and handheld system design.

Technical Context

The LD39030SJ33R employs a bandgap-referenced error amplifier with internal trimming (1.22 V reference), enabling ±2.0% output accuracy at 25 °C and ±3.0% over –40 °C to 125 °C. Its flip-chip construction minimizes parasitic inductance, supporting fast transient response (40 mV_pp load step, 100 μs soft-start).

It integrates thermal shutdown (160 °C trip, 20 °C hysteresis), short-circuit current limiting (~400 mA), and logic-level enable input (V_EN(H) = 0.9 V min, V_EN(L) = 0.4 V max) compatible with 1.2–5.5 V supply domains. PSRR remains ≥62 dB up to 10 kHz before rolling off.

Key Specifications

Pinout & Package

LD39030SJ33R uses a flip-chip 4-bump package (0.8 × 0.8 mm, 0.4 mm pitch), RoHS-compliant and ECOPACK®-qualified, with solderable bumps on underside and no wire bonds - optimized for minimal footprint and thermal resistance (R_thJA = 180 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B332MR-G and RT9013-33GB, LD39030SJ33R uniquely combines ultra-low dropout (200 mV), lowest noise (30 μV_RMS), and integrated soft-start in a 0.8 × 0.8 mm flip-chip - making it optimal for space-constrained, battery-voltage–sensitive, noise-critical portable systems.

Availability

LD39030SJ33R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, wearable health monitors, and Bluetooth LE modules requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LD39030SJ33R 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The LD39030SJ series belongs to ST's high-performance analog LDO portfolio, engineered specifically for ultra-low-power, low-noise portable electronics where battery efficiency, small form factor, and signal integrity are paramount.

FAQ

What is the minimum input voltage required for LD39030SJ33R to maintain regulation?

The LD39030SJ33R operates down to 1.5 V input, but to sustain 3.3 V output at 300 mA, VIN must exceed VOUT + VDROP - i.e., ≥3.5 V (3.3 V + 200 mV typ.). At lighter loads, regulation holds as low as 3.35 V input due to reduced dropout. Below 1.5 V, the device enters undervoltage lockout (VUVLO = 1.45 V typ.) and disables output.

Can LD39030SJ33R be used with a 1 μF ceramic output capacitor only?

Yes - the LD39030SJ33R is explicitly designed for stability with ≥1 μF X5R/X7R ceramic capacitors (ESR <2 Ω @ 100 kHz). No additional bulk capacitance is required. The datasheet confirms stable operation in Figure 21's "Stable Zone" for COUT = 1 μF and ESR ≤ 1.5 Ω, simplifying layout and reducing bill-of-materials cost.

How does the enable pin behave during power-up sequencing?

The EN pin has TTL-compatible thresholds: logic high (>0.9 V) enables regulation with 100 μs soft-start; logic low (<0.4 V) forces shutdown with <1 μA total current. During VIN ramp-up, EN must be held low until VIN exceeds 1.45 V (VUVLO) to prevent premature activation. A pull-down resistor (e.g., 100 kΩ) on EN ensures safe default-off behavior.

Is LD39030SJ33R qualified for automotive applications?

No - the LD39030SJ33R is specified for industrial temperature range (–40 °C to 125 °C) but is not AEC-Q100 qualified, nor intended for automotive safety-critical or cabin-control systems. ST offers automotive-grade variants (e.g., LD39050 series) with extended qualification; this part is intended for consumer and industrial portable equipment only.