STMicroelectronics LD39020ADTPU30R

Overview

LD39020ADTPU30R from STMicroelectronics is a high-accuracy, 3.0 V fixed-output linear voltage regulator delivering up to 200 mA with ultra-low dropout (200 mV typ. at 200 mA), ±0.5 % output tolerance at 25 °C, and 20 µA typical quiescent current at no load. It features logic-controlled enable, internal soft-start, optional output discharge MOSFET, and operates across –40 °C to 125 °C - designed for space-constrained, battery-powered systems requiring stable low-noise supply.

For engineers reviewing the LD39020ADTPU30R datasheet, LD39020ADTPU30R pinout, LD39020ADTPU30R application, or LD39020ADTPU30R equivalent, key selection criteria include dropout voltage under 200 mA load, 0.47 µF ceramic capacitor compatibility, thermal shutdown threshold (160 °C), EN pin logic thresholds (0.4 V low / 1 V high), and DFN4 1x1 package footprint constraints.

Technical Context

The LD39020ADTPU30R uses a bandgap-referenced error amplifier and PMOS pass transistor to achieve ultra-low dropout and tight output regulation. Its internal soft-start circuit limits inrush current by controlling output ramp-up over ~100 µs without external components.

It integrates an optional NMOS discharge switch (enabled in AD-series variants) that actively pulls VOUT to GND when EN is low, ensuring rapid output discharge. Protection includes thermal shutdown with 20 °C hysteresis and current limiting (250–350 mA short-circuit current).

Key Specifications

Pinout & Package

LD39020ADTPU30R is packaged in a 4-pin DFN4 1x1 mm, 0.4 mm pitch, thermally enhanced package with exposed thermal pad connected to GND. The compact footprint (1.0 × 1.0 mm) supports high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B302MR-G and RT9013-30GB, LD39020ADTPU30R uniquely combines ±0.5 % accuracy, integrated discharge, and DFN4 1x1 size - making it optimal for space-constrained, high-precision battery systems where controlled power-down sequencing matters.

Availability

LD39020ADTPU30R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, cordless phones, and portable medical devices requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for LD39020ADTPU30R 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 analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

LD39020 belongs to ST's high-accuracy, ultra-low-IQ LDO family targeting battery-powered portable electronics - engineered for minimal footprint, thermal resilience, and seamless integration with ceramic capacitors.

FAQ

What is the minimum input voltage required for LD39020ADTPU30R to maintain regulation at full 200 mA load?

The minimum input voltage is calculated as V_OUT + V_DROP = 3.0 V + 0.35 V = 3.35 V (max dropout at 200 mA and full temperature range). At room temperature, 3.2 V input suffices due to typical 200 mV dropout. Input below 3.35 V risks dropout and output collapse under worst-case conditions.

Can LD39020ADTPU30R operate stably with a 0.22 µF output capacitor?

No - while the device shows stability with ≥220 nF capacitance in ideal lab conditions, ST specifies a minimum of 0.47 µF X5R/X7R ceramic capacitor for guaranteed stability across temperature, input voltage, and load variations per Figure 17. Using 0.22 µF risks oscillation or poor transient response.

Is the thermal pad of the DFN4 1x1 package electrically connected, and how must it be handled on the PCB?

Yes - the thermal pad is internally connected to GND. It must be soldered to a dedicated PCB copper pour tied to the main analog ground plane using ≥4 thermal vias (0.3 mm diameter) to ensure effective heat dissipation and meet R_thJA = 250 °C/W spec. Leaving it floating violates thermal and electrical design requirements.

Does LD39020ADTPU30R require an input capacitor, and what value is recommended?

Yes - a minimum 1 µF X5R/X7R ceramic capacitor is required on the IN pin, placed as close as possible to the pin with short, low-inductance traces to GND. This stabilizes the input impedance and prevents oscillation during load transients; omitting it risks instability or damage under fast-switching loads.