STMicroelectronics LD39030DTPU33R

Overview

LD39030DTPU33R from STMicroelectronics is a 3.3 V, 300 mA ultra-low-dropout linear regulator IC with 300 mV typical dropout at full load, ±2.0 % output voltage tolerance at 25 °C, and 20 µA typical quiescent current at no load-designed for space-constrained, battery-powered systems such as mobile phones and digital still cameras.

For engineers reviewing the LD39030DTPU33R datasheet, LD39030DTPU33R pinout, LD39030DTPU33R application, or LD39030DTPU33R equivalent, key selection criteria include its DFN4 1×1 mm package, logic-controlled enable (EN) input, internal soft-start, optional output discharge MOSFET, and guaranteed stability with 0.47 µF ceramic output capacitor.

Technical Context

The LD39030DTPU33R implements a PMOS pass transistor architecture enabling ultra-low dropout (300 mV typ. at 300 mA), low-noise regulation (45 µV_RMS over 10 Hz–100 kHz), and high PSRR (80 dB @ 1 kHz). Its internal soft-start limits inrush current without external components.

It integrates logic-controlled shutdown (EN pin), thermal shutdown (160 °C trigger with 20 °C hysteresis), constant-current limiting, and-on the DT variant-an output discharge MOSFET (RON ≈ 100 Ω) activated during disable to rapidly deplete VOUT capacitance.

Key Specifications

Pinout & Package

LD39030DTPU33R is housed in a thermally enhanced DFN4 1×1 mm package (0.4 mm height) with an exposed thermal pad connected to GND-optimized for minimal footprint and efficient heat dissipation in portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B332MR-G and RT9013-33GB, LD39030DTPU33R uniquely combines sub-350 mV dropout, 20 µA IQ, EN control, and integrated discharge-making it optimal for compact, long-life, sequenced-power battery applications.

Availability

LD39030DTPU33R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and cordless phone systems requiring stable component supply, tight voltage accuracy, and ultra-low quiescent current.

Supply support for LD39030DTPU33R 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, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

The LD39030 belongs to ST's high-accuracy, ultra-low-IQ LDO family-engineered specifically for energy-sensitive portable electronics where battery runtime, PCB area, and power sequencing reliability are critical.

FAQ

What is the minimum input voltage required for LD39030DTPU33R to maintain regulation at 300 mA?

The maximum dropout voltage is 330 mV at 300 mA and full temperature range. Therefore, the minimum input voltage is 3.3 V + 0.33 V = 3.63 V. Below this, output voltage drops proportionally with VIN. This value is validated per Table 5 in DS11386 Rev 5.

Does LD39030DTPU33R require an external capacitor on the EN pin for noise immunity?

No external EN capacitor is required. The EN pin has built-in hysteresis and filtering; electrical characteristics specify V_IL ≤ 0.4 V and V_IH ≥ 1 V across -40 °C to 125 °C, and no external RC network is recommended or used in typical application circuits (Figure 3).

Can LD39030DTPU33R operate stably with a 220 nF output capacitor?

While the control loop remains stable down to 220 nF under ideal conditions, ST recommends ≥0.47 µF (X5R/X7R) for guaranteed stability across temperature, input voltage, and load variations-as confirmed by Figure 17 (Stability Area vs. COUT/ESR) and Section 6.3 of DS11386.

Is the thermal pad of the DFN4 1×1 package electrically connected internally?

Yes-the thermal pad is internally connected to GND. Per Table 1 and Figure 2, the pad must be soldered to a PCB GND plane to ensure proper thermal performance and electrical grounding; failure to do so risks exceeding junction temperature limits and violating absolute maximum ratings.