STMicroelectronics LE52ABD

Overview

LE52ABD from STMicroelectronics is a very low dropout (LDO) linear voltage regulator delivering 5.2 V ±1% output at up to 100 mA, featuring 0.2 V typical dropout voltage, 50 µA quiescent current in OFF mode, and TTL-compatible inhibit control (pin 5 in SO-8). It operates across –40 °C to 125 °C and requires only a 2.2 µF ceramic output capacitor for stability-enabling compact, low-power local regulation in battery-powered sensor nodes and portable instrumentation.

For engineers reviewing the LE52ABD datasheet, LE52ABD pinout, LE52ABD application, or LE52ABD equivalent, key selection criteria include its precise 5.2 V output tolerance, ultra-low OFF-mode current draw, SO-8 package with integrated thermal flag, and compatibility with legacy L78Lxx footprints while adding active shutdown capability.

Technical Context

The LE52ABD implements a PNP-based pass transistor architecture enabling sub-0.3 V dropout at full 100 mA load across temperature, with internal current limiting and thermal shutdown protection. Its inhibit input accepts TTL-level logic (V_IL ≤ 0.8 V, V_IH ≥ 2 V) to disable output and reduce quiescent current to 50 µA.

Designed for noise-sensitive analog and mixed-signal systems, it achieves 80 dB supply voltage rejection at 120 Hz and delivers 50 µV_RMS output noise (10 Hz–100 kHz), supported by minimal 2.2 µF output capacitance with ESR between 0.1 Ω and 10 Ω.

Key Specifications

Pinout & Package

LE52ABD is packaged in an SO-8 surface-mount package with pins 2, 3, 6, and 7 internally connected to the die attach flag for enhanced thermal dissipation (R_thJA = 55 °C/W). The inhibit function is implemented on pin 5, requiring grounding when unused to prevent noise-induced shutdown.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDL112P50R and TS29375, LE52ABD uniquely combines 5.2 V precision, 0.2 V dropout, and TTL inhibit in SO-8 - making it optimal for space-constrained, battery-aware systems needing exact voltage and dynamic power gating.

Availability

LE52ABD is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial wireless transmitters, and smart metering subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LE52ABD 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, designing and manufacturing microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

LE52ABD belongs to ST's LExxAB series of precision LDO regulators, engineered specifically for low-noise, low-quiescent-current local regulation in battery-powered and thermally demanding embedded systems.

FAQ

What is the minimum input voltage required for LE52ABD to maintain regulation at 100 mA load?

The LE52ABD maintains regulation down to V_IN = V_OUT + V_DROP. With a typical dropout of 0.2 V and nominal 5.2 V output, the minimum functional input is 5.4 V at 100 mA and 25 °C. At –40 °C to 125 °C, worst-case dropout rises to 0.5 V, requiring ≥5.7 V input for guaranteed regulation across temperature.

Can LE52ABD be used without connecting the INHIBIT pin?

Yes - if the INHIBIT pin (pin 5) is left unconnected, the device defaults to ON mode. However, ST explicitly recommends grounding this pin when shutdown functionality is unused to prevent noise coupling and unintended turn-off, especially in electrically noisy environments like automotive or industrial settings.

Is the 2.2 µF output capacitor requirement strict, or can larger values be used?

The 2.2 µF value is the minimum recommended ceramic capacitor (with ESR 0.1–10 Ω) for guaranteed stability per ST's characterization. Larger values (e.g., 4.7 µF or 10 µF) are acceptable and may improve transient response, but must remain within the specified ESR range - polymer or electrolytic capacitors outside this ESR window risk oscillation.

How does the SO-8 thermal flag configuration affect PCB layout?

Pins 2, 3, 6, and 7 are internally connected to the die attach flag, forming a low-thermal-resistance path to PCB copper. To realize the rated R_thJA = 55 °C/W, at least 1 cm² of 2-oz copper connected to these pins via multiple thermal vias is required - insufficient copper area will degrade thermal performance and limit safe continuous current.