STMicroelectronics LD39020ADTPU25R

Overview

LD39020ADTPU25R from STMicroelectronics is a 2.5 V, ±0.5 % accuracy ultra-low-dropout linear regulator delivering up to 200 mA with 200 mV typical dropout at full load, 20 µA typical quiescent current at no load, and logic-controlled enable/shutdown. It operates from 1.5 V to 5.5 V input and is optimized for space-constrained, battery-powered systems such as mobile phone core voltage rails and portable media player audio subsystems.

For engineers reviewing the LD39020ADTPU25R datasheet, LD39020ADTPU25R pinout, LD39020ADTPU25R application, or LD39020ADTPU25R equivalent, key selection criteria include output accuracy tolerance, shutdown current (<0.1 µA), ceramic capacitor compatibility (≥0.47 µF), thermal performance in DFN4 1x1 package, and integrated soft-start/discharge functionality.

Technical Context

The LD39020ADTPU25R employs a bandgap-referenced error amplifier with internal bias generator and thermal protection circuitry. Its enable-controlled NMOS pass transistor supports fast turn-on (100 µs) and integrates an optional discharge MOSFET (enabled in ADT variant) that actively pulls VOUT to GND during shutdown.

Stability is achieved via internal compensation designed for ceramic output capacitors (0.47–22 µF) with ESR <10 Ω; the control loop maintains regulation across –40 °C to 125 °C junction temperature while rejecting supply ripple (80 dB @ 1 kHz, 55 dB @ 100 kHz).

Key Specifications

Pinout & Package

LD39020ADTPU25R is housed in a 4-pin DFN4 1x1 mm package with exposed thermal pad connected to GND. The compact footprint supports high-density portable designs while enabling efficient heat transfer to the PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B252MR-G and RT9013-25GB, LD39020ADTPU25R provides superior accuracy (±0.5 %), integrated discharge, and smaller DFN4 1x1 footprint - making it optimal for next-gen portable devices demanding minimal leakage, fast state transitions, and space efficiency.

Availability

LD39020ADTPU25R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and portable media players requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for LD39020ADTPU25R 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.

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 in space- and power-constrained designs.

FAQ

What is the minimum output capacitance required for stable operation?

The LD39020ADTPU25R is stable with a minimum 0.47 µF X5R or X7R ceramic capacitor on the output. This value ensures robust phase margin across –40 °C to +125 °C and under full 200 mA load transients. Using smaller values risks oscillation, especially at temperature extremes or with high-ESR capacitors.

Does LD39020ADTPU25R support adjustable output voltage?

No - LD39020ADTPU25R is a fixed-output 2.5 V regulator. ST offers other members of the LD39020 family (e.g., LD39020DTPU25R) with ±2 % tolerance and same pinout, but no version supports external resistor programming. Output voltage is laser-trimmed during production and not user-configurable.

How does the output discharge feature behave during shutdown?

When EN is pulled low, the internal discharge MOSFET (RON ≈ 100 Ω) connects VOUT directly to GND, discharging a 10 µF output capacitor from 2.5 V to <0.1 V in under 250 µs. This prevents back-powering of upstream circuitry and ensures deterministic power-down sequencing in multi-rail systems.

Can LD39020ADTPU25R be used with input voltages below 1.5 V?

No - the absolute minimum input voltage is 1.5 V per datasheet specifications. Operation below this threshold may cause loss of regulation, increased dropout, or undefined behavior. For sub-1.5 V inputs, consider ST's LD39200 series or alternative ultra-low-V_IN LDOs with different architecture.