STMicroelectronics ST2L05-3300K5

Overview

ST2L05-3300K5 from STMicroelectronics is a dual low-dropout linear voltage regulator IC with fixed 3.3V output on VO1 and adjustable output (1.25V to VI − VDROP) on VO2, delivering up to 1A per channel, ±2% output tolerance at 25°C, 1.3V dropout at 1A, and thermal shutdown protection. It targets data storage power rails in HDD and optical drives.

For engineers reviewing the ST2L05-3300K5 datasheet, ST2L05-3300K5 pinout, ST2L05-3300K5 application, or ST2L05-3300K5 equivalent, key selection criteria include dual-rail stability with low-ESR ceramic capacitors, thermal resistance of 2°C/W (Junction-to-Case) in DFN package, fixed/adjustable output flexibility, and guaranteed 1A current per channel across 0°C to 125°C.

Technical Context

This dual LDO integrates two independent regulator blocks: VO1 is factory-trimmed to 3.3V with ±2% accuracy at 25°C and ±3% over temperature; VO2 uses an internal 1.25V reference (±1.2% initial tolerance) and external resistor divider for adjustable output from 1.25V to VI − VDROP. Both outputs feature current limiting and thermal shutdown.

The device employs internal power limiting and thermal foldback to protect against overload and junction overheating. Its stability architecture supports X7R ceramic output capacitors ≥4.7µF (with ESR ≥10mΩ), and it maintains regulation down to 2mA minimum load on the adjustable output - critical for microcontroller biasing in low-power states.

Key Specifications

Pinout & Package

ST2L05-3300K5 is housed in an 8-pin DFN 5×6mm surface-mount package with exposed thermal pad (pin 6). The package provides 2°C/W Junction-to-Case thermal resistance and is optimized for PCB heat spreading in space-constrained storage modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and TSM102IDT, ST2L05-3300K5 uniquely integrates dual independent LDOs with fixed+adjustable topology, thermal protection, and DFN-package thermal efficiency - making it the only drop-in solution for space-constrained dual-rail storage power systems.

Availability

ST2L05-3300K5 is available at Aetrix Electronics and suitable for hard disk drives, optical disc drives (CD/DVD-ROM/RW), combo drives, and embedded flash storage modules requiring stable component supply, thermal robustness, and dual-output integration.

Supply support for ST2L05-3300K5 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 automotive-grade ICs with broad industrial qualification.

The ST2L05 series belongs to ST's dedicated data storage power management portfolio, designed specifically to consolidate dual-rail regulation in HDD, optical, and hybrid storage subsystems with minimal footprint and thermal overhead.

FAQ

What is the minimum load required on the adjustable output (VO2) of ST2L05-3300K5?

The adjustable output requires a minimum load current of 2mA across the full operating temperature range (0°C to 125°C) to maintain regulation. This is specified in the Electrical Characteristics table for adjustable output and verified in Figure 7 (Minimum Load Current vs Temperature). Below this threshold, VO2 may drift outside tolerance due to reference bias current limitations.

Can ST2L05-3300K5 operate with ceramic capacitors smaller than 4.7µF?

No - the datasheet mandates ≥4.7µF X7R ceramic capacitors on both VO1 and VO2 for guaranteed stability. Smaller values risk oscillation due to insufficient phase margin, especially with low-ESR MLCCs. The Application Hints section explicitly states that 4.7µF is the tested minimum, and stability degrades below this value even with higher-quality dielectrics.

Is the exposed pad (Pin 6) of the DFN package electrically connected internally?

Yes - the exposed thermal pad (EP) is internally connected to GND and must be soldered to a PCB copper pour tied to the analog ground plane. This connection is essential for achieving the specified 2°C/W Junction-to-Case thermal resistance and preventing thermal shutdown under 1A load conditions.

Does ST2L05-3300K5 support input voltages above 7V?

No - the Absolute Maximum Rating for VI is 10V, but the Recommended Operating Condition limits VI to 4.5V–7V. Operation above 7V violates recommended conditions and risks exceeding thermal limits due to increased dropout dissipation; the device is not characterized or guaranteed for reliability beyond 7V input.