STMicroelectronics LD39020ADTPU33R

Overview

LD39020ADTPU33R from STMicroelectronics is a 3.3 V, ±0.5 % accuracy, 200 mA ultra-low-dropout linear regulator in DFN4 1x1 package, featuring 200 mV typical dropout at full load, 20 µA typical quiescent current at no load, and logic-controlled enable with 0.03 µA standby current-designed for precision power rails in battery-powered mobile phones and digital still cameras.

For engineers reviewing the LD39020ADTPU33R datasheet, LD39020ADTPU33R pinout, LD39020ADTPU33R application, or LD39020ADTPU33R equivalent, key selection criteria include output voltage tolerance (±0.5 %), dropout performance at 200 mA, thermal shutdown threshold (160 °C), soft-start timing (100 µs), and compatibility with 0.47 µF ceramic output capacitors.

Technical Context

The LD39020ADTPU33R integrates a bandgap reference, error amplifier, and PMOS pass transistor in a fully internal compensation architecture stabilized with ≥0.47 µF ceramic output capacitance. Its enable-controlled shutdown disables regulation and activates optional output discharge via an internal MOSFET (RON = 100 Ω).

It delivers regulated 3.3 V output across input voltages from 1.5 V to 5.5 V, with PSRR of 80 dB at 1 kHz and 55 dB at 100 kHz, and maintains stability over −40 °C to +125 °C junction temperature while providing constant-current limiting and thermal foldback protection.

Key Specifications

Pinout & Package

LD39020ADTPU33R is housed in a 1 mm × 1 mm, 0.37 mm height DFN4 1x1 package with exposed thermal pad connected to GND for enhanced thermal dissipation (R_thJA = 250 °C/W). The 4-pin configuration excludes NC and integrates GND directly beneath the die for minimal loop inductance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B332MR-G and RT9013-33GB, LD39020ADTPU33R uniquely combines ±0.5 % accuracy, integrated output discharge, and DFN4 1x1 footprint-making it optimal for space-constrained, precision battery-powered designs requiring controlled power-down behavior.

Availability

LD39020ADTPU33R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and cordless phone systems requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.

Supply support for LD39020ADTPU33R 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, specializing in automotive, industrial, and power management ICs with broad manufacturing and quality certifications.

LD39020ADTPU33R belongs to ST's high-accuracy, ultra-low-I_Q LDO family targeting battery-operated portable electronics where precision regulation, minimal standby loss, and small form factor are critical.

FAQ

What is the minimum output capacitor required for stable operation?

The LD39020ADTPU33R is stable with a minimum 0.47 µF X5R or X7R ceramic capacitor on the output. This value ensures phase margin >45° across −40 °C to +125 °C and full load range. Using smaller capacitors (e.g., 220 nF) may cause instability under temperature or load transients.

Does LD39020ADTPU33R include output discharge functionality?

Yes-LD39020ADTPU33R includes an integrated NMOS discharge switch (RON ≈ 100 Ω) that connects VOUT to GND when the EN pin is driven low. This feature rapidly discharges external output capacitance, preventing residual voltage from interfering with downstream logic sequencing.

What is the thermal performance difference between DFN4 1x1 and SOT23-5L packages?

DFN4 1x1 offers R_thJA = 250 °C/W, while SOT23-5L has R_thJA = 255 °C/W-nearly identical ambient thermal resistance. However, DFN4's exposed thermal pad provides lower R_thJC, enabling better heat transfer to PCB copper layers when properly soldered and thermally anchored.

Can LD39020ADTPU33R operate with input voltage below 3.3 V?

No-it cannot regulate 3.3 V output when input falls below the sum of output voltage and dropout voltage. With 200 mV typical dropout at 200 mA, minimum functional VIN is ~3.5 V. At lighter loads (e.g., 30 mA), dropout drops to 35 mV, allowing operation down to ~3.34 V.