STMicroelectronics ST1L02PU33R

Overview

ST1L02PU33R from STMicroelectronics is a fixed 3.3 V, 1 A low-dropout linear voltage regulator in DFN6D (3×3 mm) package, fabricated in BiCMOS technology. It delivers ±2% output voltage tolerance at 25 °C, maintains ≤650 µA quiescent current over 0–125 °C junction temperature, and achieves 0.7 V typical dropout at 1 A load-optimized for HDD read channel and memory chip power delivery.

For engineers reviewing the ST1L02PU33R datasheet, ST1L02PU33R pinout, ST1L02PU33R application, or ST1L02PU33R equivalent, key selection criteria include low-ESR ceramic capacitor stability, thermal shutdown with hysteresis, overcurrent protection, and compatibility with compact data storage PCB layouts requiring high PSRR (50–75 dB) and low RMS noise (0.003% VO).

Technical Context

The ST1L02PU33R employs BiCMOS process technology to tightly regulate quiescent current across temperature while enabling stable operation with 4.7 µF ceramic input/output capacitors. Its internal architecture integrates precision bandgap reference, error amplifier, and current-limiting circuitry with thermal foldback.

It features dual-stage protection: current limiting triggers at ≥1.0 A and thermal shutdown activates at 165 °C with hysteresis. The device supports both standard (VO only) and sense-enabled (VO + VO_SENSE) configurations-though ST1L02PU33R uses the non-sense variant per Table 2 pin mapping.

Key Specifications

Pinout & Package

ST1L02PU33R is housed in a thermally enhanced DFN6D (3×3 mm, 0.75 mm height) package with exposed GND pad. Pin 2 connects to the exposed thermal pad, which must be soldered to a PCB copper pour for optimal thermal performance (R_thJA = 55 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3.3 V, 1 A LDO applications.

Compared with XC6206P332MR and NCP1117ST33T3G, ST1L02PU33R uniquely balances 1 A capability, sub-1 mA IQ, DFN6D footprint, and ceramic-stable operation-making it the only fit for thermally dense, noise-sensitive HDD/SSD power rails.

Availability

ST1L02PU33R is available at Aetrix Electronics and suitable for HDD read channel power, SSD NAND interface, embedded storage controller, and industrial data logger applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for ST1L02PU33R 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 industrial, automotive, and consumer markets.

The ST1L02xx series was developed specifically for high-reliability, low-noise power delivery in data storage systems-emphasizing thermal robustness, ceramic capacitor compatibility, and tight output regulation under dynamic load.

FAQ

What is the minimum input voltage required for ST1L02PU33R to regulate at full 1 A load?

The minimum input voltage is 4.0 V, derived from the 3.3 V output plus 0.7 V typical dropout voltage at 1 A. Absolute maximum VI is 10 V, and operation below 3.3 V will cause dropout-confirmed by Figure 9 (dropout vs. temperature) and Table 7 test conditions specifying VI ≥ 4.5 V for full characterization.

Can ST1L02PU33R be used with aluminum polymer or tantalum output capacitors instead of ceramic?

Yes-the datasheet explicitly states stability with "either tantalum and ceramic capacitors" (Section 5, Typical Application). However, ceramic is preferred due to lower ESR, smaller footprint, and absence of aging effects; aluminum polymer may require series resistance verification per application note AN2717.

Does ST1L02PU33R include reverse polarity or reverse current protection?

No-ST1L02PU33R lacks integrated reverse polarity or reverse current blocking. If VI falls below VO (e.g., during power-down), current can flow backward from VO to VI through the internal pass transistor. External Schottky diode or ideal diode IC is required for backfeed prevention.

Is the exposed thermal pad on the DFN6D package electrically connected, and how should it be handled in PCB layout?

Yes-the exposed pad is internally connected to Pin 2 (GND) and serves as the primary thermal and electrical ground path. It must be soldered to a dedicated PCB copper pour with ≥4 thermal vias (0.3 mm diameter) to an inner ground plane; insufficient thermal relief increases R_thJA and risks thermal shutdown under 1 A continuous load.