STMicroelectronics LD39020ATPU33R

Overview

LD39020ATPU33R from STMicroelectronics is a high-accuracy, 3.3 V fixed-output linear voltage regulator delivering up to 200 mA with 200 mV typical dropout at full load, ±0.5 % output voltage tolerance at 25 °C, and ultra-low 20 µA quiescent current at no load - designed for power-sensitive battery-operated systems such as digital still cameras and portable media players.

For engineers reviewing the LD39020ATPU33R datasheet, LD39020ATPU33R pinout, LD39020ATPU33R application, or LD39020ATPU33R equivalent, key selection criteria include dropout performance under 200 mA load, thermal shutdown behavior at 160 °C, soft-start timing (100 µs), enable logic compatibility (0.4 V low / 1 V high thresholds), and ceramic capacitor stability down to 0.47 µF.

Technical Context

The LD39020ATPU33R employs a bandgap-referenced error amplifier and internal PMOS pass transistor to regulate output voltage with high line/load regulation (0.02 %/V and 10 mV respectively) and low noise (45 µV_RMS, 10 Hz–100 kHz). Its integrated soft-start circuit limits inrush current without external components.

Logic-controlled enable (EN) input supports system-level power sequencing, while optional output discharge MOSFET (not present in AT variant) is omitted here - confirmed by order code "ATPU33R" indicating no auto-discharge function and ±0.5 % accuracy grade. Thermal protection triggers at 160 °C with 20 °C hysteresis.

Key Specifications

Pinout & Package

LD39020ATPU33R is available in SOT23-5L package (2.95 mm × 1.60 mm × 1.45 mm) with exposed pad not connected internally. Pin assignment is identical across variants: Pin 1 = IN, Pin 2 = GND, Pin 3 = EN, Pin 4 = NC (no connect), Pin 5 = OUT.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD39020ATPU33R, XC6210B332MR-G lacks current headroom for camera sensor loads, while BD39020MUV-LB sacrifices 0.5 % accuracy and adds 10 µA IQ - making the ST part optimal for designs demanding tight regulation and lowest possible standby drain.

Availability

LD39020ATPU33R is available at Aetrix Electronics and suitable for digital still cameras, portable media players, and cordless phone systems requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability in extended temperature environments.

Supply support for LD39020ATPU33R 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, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The LD39020 series belongs to ST's high-accuracy, ultra-low-I_Q LDO portfolio - engineered specifically for space-constrained, battery-powered applications where dropout, noise, and standby current are critical system-level constraints.

FAQ

Is LD39020ATPU33R RoHS-compliant and halogen-free?

Yes. LD39020ATPU33R is manufactured in STMicroelectronics' ECOPACK2-compliant SOT23-5L package, meeting RoHS Directive 2011/65/EU and halogen-free requirements per IEC 61249-2-21. Full compliance documentation is available in ST's official product change notices and material declarations.

Does LD39020ATPU33R require an external discharge resistor for the output?

No. The "AT" suffix confirms this variant lacks the internal output discharge MOSFET (present only in "ADT" or "DT" versions). When disabled, the output floats; if rapid discharge is required, an external 100 kΩ–1 MΩ pull-down resistor must be added between VOUT and GND.

Can LD39020ATPU33R operate with a 0.22 µF output capacitor?

No. While the device remains stable down to 220 nF under ideal lab conditions, ST specifies a minimum of 0.47 µF ceramic capacitor (X5R/X7R) for guaranteed stability across temperature, input voltage, and load variations - using 0.22 µF risks oscillation or poor transient response.

What is the maximum allowable input voltage for continuous operation?

The absolute maximum input voltage is 7 V, but continuous operation must remain within the recommended operating range of 1.5 V to 5.5 V. Exceeding 5.5 V risks parametric shift or accelerated degradation, even if below the 7 V absolute limit - design margins should enforce 5.5 V as the hard ceiling.