STMicroelectronics ST1L05DPUR

Overview

ST1L05DPUR from STMicroelectronics is an adjustable-output, low-dropout linear voltage regulator in DFN8 (4×4 mm) package, delivering up to 1.3 A with ±2% output voltage tolerance at 25 °C, 650 µA max quiescent current, and 0.3 V typical dropout at full load. It integrates enable and Power Good functions, and is optimized for data storage systems requiring stable, low-noise 3.3 V supply to read channel and memory ICs.

For engineers reviewing the ST1L05DPUR datasheet, ST1L05DPUR pinout, ST1L05DPUR application, or ST1L05DPUR equivalent, key selection criteria include its adjustable output configuration (ADJ pin), dual-function EN/PG interface, thermal shutdown with hysteresis, stability with low-ESR ceramic capacitors, and suitability for high-reliability HDD power rails where low IQ and tight regulation are critical.

Technical Context

The ST1L05DPUR implements a BiCMOS-based error amplifier and pass transistor architecture, enabling precise output voltage control via external resistor divider on the ADJ pin (1.22 V reference). Its internal bandgap reference and op-amp feedback loop maintain regulation across 0–125 °C junction temperature.

It features active enable logic with 0.8 V/2 V thresholds and an open-drain Power Good output asserting when VO reaches 92% of target, with hysteresis for noise immunity. Thermal protection triggers at 165 °C with automatic recovery upon cooling.

Key Specifications

Pinout & Package

ST1L05DPUR uses an 8-pin DFN (4×4 mm, 0.5 mm pitch) package with exposed thermal pad. Pin 1 is marked by a dot; the exposed pad must be soldered to a large GND copper area for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B332MR-G and ADM7172ACPZ-3.3-R7, ST1L05DPUR uniquely balances adjustability, integrated power management (EN/PG), ultra-low IQ, and 1.3 A capability in a thermally efficient DFN8 - making it the only choice for space-constrained, sequenced, and battery-sensitive HDD/SSD power designs.

Availability

ST1L05DPUR is available at Aetrix Electronics and suitable for HDD read channel power, SATA SSD controller rails, industrial data logger core supplies, and embedded storage module bias requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for ST1L05DPUR 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 microcontrollers, power management ICs, sensors, and automotive-grade components.

The ST1L05 series belongs to ST's high-efficiency linear regulator product line, engineered specifically for data storage applications demanding ultra-low quiescent current, precise output accuracy, and integrated power sequencing functions in minimal footprint packages.

FAQ

What is the minimum input voltage required for ST1L05DPUR to regulate 3.3 V output?

The ST1L05DPUR requires a minimum input voltage of 3.6 V to sustain 3.3 V output at 1.3 A load, based on its 0.3 V typical dropout specification. At lighter loads (e.g., 100 mA), regulation is maintained down to ~3.35 V input. The absolute minimum start-up voltage is 2.9 V per datasheet Table 9 footnote 1.

Can ST1L05DPUR be used with only ceramic output capacitors?

Yes - ST1L05DPUR is explicitly designed for stability with low-ESR ceramic capacitors (≥4.7 µF X7R). Figure 13 confirms stable operation with ESR as low as 5 mΩ. No series resistance or tantalum/Al-elec supplementation is needed, reducing cost and improving long-term reliability.

How does the Power Good (PG) pin behave during thermal shutdown?

During thermal shutdown, the PG pin remains asserted (high-impedance/floating) as long as VO stays above 80% of target. Once VO collapses below that threshold due to overload or excessive dropout, PG pulls low. Upon recovery and VO re-stabilization ≥92%, PG returns to high-impedance state - no latching behavior is implemented.

Is the exposed thermal pad on ST1L05DPUR electrically connected to GND?

Yes - the exposed pad is internally connected to GND and must be soldered to a dedicated GND copper pour on the PCB. This connection is essential for both thermal dissipation (R_thJA = 40 °C/W) and electrical noise reduction; leaving it unconnected degrades thermal performance and may cause instability or premature thermal shutdown.