STMicroelectronics LD39020DTPU18R

Overview

LD39020DTPU18R from STMicroelectronics is a 200 mA ultra-low-dropout linear voltage regulator with 1.8 V fixed output, 200 mV typical dropout at 200 mA, ±2.0 % output tolerance at 25 °C, 20 µA typical quiescent current at no load, and logic-controlled enable (EN) for shutdown mode. It operates from 1.5 V to 5.5 V input and is used in battery-powered mobile phones and digital still cameras requiring stable low-noise power.

For engineers reviewing the LD39020DTPU18R datasheet, LD39020DTPU18R pinout, LD39020DTPU18R application, or LD39020DTPU18R equivalent, key selection criteria include dropout voltage under 200 mA load, standby current below 0.1 µA, PSRR of 80 dB at 1 kHz, compatibility with 0.47 µF ceramic output capacitors, and dual-package availability (DFN4 1x1 and SOT23-5L).

Technical Context

The LD39020DTPU18R implements a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout operation without external compensation. Its internal soft-start circuit limits inrush current during enable transitions, with turn-on time specified at 100 µs.

It integrates thermal shutdown (160 °C trip, 20 °C hysteresis), current limiting (~300 mA), and optional output discharge MOSFET (not present in DTPU variant per order code table). The EN pin accepts logic-level inputs (V_IL ≤ 0.4 V, V_IH ≥ 1 V) across full temperature range.

Key Specifications

Pinout & Package

LD39020DTPU18R is available in DFN4 1x1 (1.0 mm × 1.0 mm, 0.4 mm height) and SOT23-5L packages. Both are RoHS-compliant ECOPACK® variants with exposed thermal pad (DFN4) or standard leadframe (SOT23-5L).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B182MR-G, LD39020DTPU18R adds integrated enable and thermal protection at modest IQ penalty; versus ADP125ARHZ-1.8-R7, it trades current headroom and dropout for 40% smaller DFN4 footprint and lower unit cost in high-volume portable designs.

Availability

LD39020DTPU18R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and cordless phone systems requiring stable component supply with tight parametric consistency and long-term manufacturability.

Supply support for LD39020DTPU18R 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, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

LD39020 belongs to ST's high-accuracy, ultra-low-IQ LDO family targeting space-constrained, battery-operated devices where efficiency, noise, and reliability are critical - especially in portable imaging and communication equipment.

FAQ

What is the maximum input voltage for LD39020DTPU18R?

The absolute maximum input voltage is 7 V, but the recommended operating range is 1.5 V to 5.5 V per datasheet Section 4 (Table 2). Exceeding 5.5 V risks violating safe operating area limits and may trigger internal protection circuits even if within absolute max ratings.

Does LD39020DTPU18R include output discharge functionality?

No. Per Table 10 (Order Code), LD39020DTPU18R is the standard version without auto-discharge MOSFET. Only part numbers with "AD" prefix (e.g., LD39020ADTPU18R) integrate the optional discharge FET. This variant relies on external bleeder resistors for output discharge.

Can LD39020DTPU18R be stabilized with a 0.22 µF ceramic capacitor?

No. The minimum recommended output capacitance is 0.47 µF (Section 6.3, Figure 17). While stability is theoretically possible at 220 nF under narrow conditions, 0.22 µF falls outside the validated stability region across temperature, input voltage, and load variations - risking oscillation or poor transient response.

What is the thermal resistance junction-to-ambient for the DFN4 1x1 package?

R_thJA is 250 °C/W for the DFN4 1x1 package (Table 3, DS9956 Rev 6, page 5). This value assumes standard JEDEC 2-layer board layout; actual performance improves significantly with PCB copper pour connected to the thermal pad, potentially reducing R_thJA to ~60–80 °C/W in optimized layouts.