STMicroelectronics LD39020ATPU32R

Overview

LD39020ATPU32R from STMicroelectronics is a high-accuracy, 3.2 V fixed-output linear voltage regulator delivering up to 200 mA with ultra-low dropout (200 mV typ. at 200 mA), ±0.5 % output voltage tolerance at 25 °C, and 20 µA typical quiescent current at no load. It features logic-controlled enable, internal soft-start, thermal/overcurrent protection, and operates from 1.5 V to 5.5 V input - optimized for space-constrained, battery-powered mobile and portable media systems.

For engineers reviewing the LD39020ATPU32R datasheet, LD39020ATPU32R pinout, LD39020ATPU32R application, or LD39020ATPU32R equivalent, key selection criteria include dropout performance under 200 mA load, standby current <0.1 µA in shutdown, ceramic capacitor compatibility (≥0.47 µF), and dual-package availability (DFN4 1x1 / SOT23-5L) for PCB area optimization.

Technical Context

The LD39020ATPU32R uses a bandgap-referenced error amplifier with internal bias generator and thermal shutdown circuitry to maintain regulation across –40 °C to +125 °C junction temperature. Its low-noise architecture achieves 45 µV_RMS output noise (10 Hz–100 kHz) and 80 dB PSRR at 1 kHz, enabling clean power for RF-sensitive analog circuits and precision ADCs.

Enable control is implemented via a CMOS-compatible input (logic high ≥1 V, low ≤0.4 V), triggering fast turn-on (<100 µs) and controlled discharge only on variants with integrated discharge MOSFET - which the ATPU32R lacks (no auto-discharge). Stability is ensured with ceramic output capacitors as low as 0.47 µF and ESR <15 Ω.

Key Specifications

Pinout & Package

LD39020ATPU32R is available in two compact packages: DFN4 1x1 mm (0.4 mm height) and SOT23-5L (2.95 × 1.60 mm). Both are RoHS-compliant, halogen-free ECOPACK® variants. The DFN4 includes an exposed thermal pad connected to GND for enhanced thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, high-accuracy LDO applications.

Compared with XC6210B322MR-G and BD39020MUV-E2, LD39020ATPU32R uniquely combines ±0.5 % accuracy, 200 mV dropout at full load, sub-1 µA shutdown current, and dual-package flexibility - making it optimal for next-gen portable devices demanding precision, efficiency, and miniaturization.

Availability

LD39020ATPU32R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and portable media players requiring stable component supply with long-term lifecycle support and traceable sourcing.

Supply support for LD39020ATPU32R 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 since 1987.

LD39020 belongs to ST's high-performance LDO portfolio targeting ultra-low-power, space-constrained battery-operated devices - emphasizing accuracy, low noise, and seamless integration with modern mixed-signal SoCs.

FAQ

What is the minimum output capacitor value required for stable operation of LD39020ATPU32R?

The LD39020ATPU32R is stable with a minimum 0.47 µF X5R or X7R ceramic capacitor on the output. While the control loop functions down to 220 nF, 0.47 µF is the recommended minimum to ensure stability across temperature, input voltage, and load variations - especially critical in battery-powered systems where ESR shifts with cell discharge.

Does LD39020ATPU32R include an output discharge function?

No. LD39020ATPU32R does not integrate the output discharge MOSFET - this feature is only present in "ADT" or "DTPU" suffix variants (e.g., LD39020ADTPU32R). The ATPU32R variant relies on external discharge circuitry if rapid VOUT decay during shutdown is required.

Can LD39020ATPU32R operate with a 1.5 V input while delivering 3.2 V output?

No. LD39020ATPU32R is a step-down linear regulator with fixed 3.2 V output; it cannot boost voltage. Minimum input is 3.4 V (3.2 V + 200 mV dropout) for full 200 mA load. At 1.5 V input, regulation is impossible - the device will be in dropout and output will track input minus losses.

What is the thermal resistance (R_thJA) for LD39020ATPU32R in DFN4 1x1 package?

In the DFN4 1x1 package, LD39020ATPU32R has a junction-to-ambient thermal resistance (R_thJA) of 250 °C/W under standard JEDEC 51-7 PCB conditions (2-layer board, 1 in² copper). With proper thermal pad soldering to a multi-layer GND plane, effective R_thJA can improve to ~120 °C/W in production layouts.