STMicroelectronics ST2L05-3300PT

Overview

ST2L05-3300PT 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 ST2L05-3300PT datasheet, ST2L05-3300PT pinout, ST2L05-3300PT application, or ST2L05-3300PT equivalent, key selection criteria include dual-output independence, DFN 5×6mm package thermal resistance (2°C/W), low quiescent current (7mA max), stability with low-ESR ceramic capacitors, and adjustable VO2 configuration for mixed-voltage microcontroller supply.

Technical Context

The ST2L05-3300PT integrates two independent LDO regulators: VO1 is factory-trimmed to 3.3V with ±2% accuracy at 25°C and ±3% over 0–125°C; VO2 uses an internal 1.25V reference (±1.2% initial tolerance) and external resistor divider for programmable output from 1.25V to VI − VDROP. Both outputs feature current limiting and thermal shutdown.

It employs internal power limiting and thermal foldback to protect against overload and junction overheating, with thermal shutdown triggered at 175°C and 5°C hysteresis. The device is optimized for stability with X7R ceramic output capacitors ≥4.7µF placed within 0.5 inches of VO1/VO2 pins, and supports input ripple ≤±0.15V across 4.5–7V operating range.

Key Specifications

Pinout & Package

ST2L05-3300PT is housed in an 8-pin DFN 5×6mm surface-mount package with exposed thermal pad (pin 6), offering 2°C/W junction-to-case thermal resistance. Pin numbering follows top-through view per datasheet Figure 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A8801RTJT and NCP1595ADR2G, ST2L05-3300PT uniquely combines 1A dual-channel capability, factory-trimmed 3.3V VO1, and fully adjustable VO2 in a thermally efficient DFN package-enabling single-chip dual-rail power for HDD and optical drive mainboards without compromising current capacity or flexibility.

Availability

ST2L05-3300PT is available at Aetrix Electronics and suitable for hard disk drive (HDD), CD/DVD-ROM, CD/DVD-R/RW, and combo drive (DVD-ROM + CD-R/RW) designs requiring stable component supply, thermal robustness, and dual-voltage programmability.

Supply support for ST2L05-3300PT 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, automotive ICs, and microcontrollers with strong IP in analog and mixed-signal design.

The ST2L05 product line was developed specifically for data storage applications, integrating dual LDOs with high current, low dropout, and thermal resilience to replace discrete solutions in HDD and optical drive power systems.

FAQ

What is the minimum required output capacitance for stable operation of ST2L05-3300PT?

The ST2L05-3300PT requires ≥4.7µF X7R ceramic capacitors on both VO1 and VO2 pins, placed within 0.5 inches of their respective output terminals and returned to a clean analog ground. Lower values (≥2.2µF) may suffice only if the input capacitor is ≥4.7µF; use of Y5V ceramics is not recommended due to temperature-dependent ESR shifts.

Can ST2L05-3300PT be used with a 3.0V input supply?

No. ST2L05-3300PT requires a minimum input voltage of 4.5V to maintain regulation on its 3.3V VO1 output, given its 1.3V dropout at 1A. With 3.0V input, VO1 would drop out of regulation. The absolute minimum VI is 4.5V; maximum is 7V per absolute maximum ratings.

How is the adjustable output (VO2) voltage calculated and what resistor tolerance is recommended?

VO2 = 1.25V × (1 + R1/R2), where R1 connects VO2 to ADJ (pin 2) and R2 connects ADJ to GND (pin 3). I_ADJ (≤1µA) is negligible in calculation. Use 1% tolerance metal-film resistors; R2 = 10kΩ is typical, yielding R1 = 14kΩ for 2.8V output. Ensure minimum load current ≥2mA on VO2 across temperature.

Does ST2L05-3300PT require a heatsink in standard HDD applications?

No external heatsink is required. Its DFN 5×6mm package has 2°C/W junction-to-case thermal resistance and internal thermal shutdown (175°C). At 1A per channel and 125°C ambient, junction temperature remains ≤110°C with a 1-in² 2-oz copper pour under the EP pad-meeting typical HDD thermal envelopes without added thermal mass.