STMicroelectronics LE33CZ-TR

Overview

LE33CZ-TR from STMicroelectronics is a 3.3 V, ±2% tolerance, very low-dropout linear voltage regulator in TO-92 package with 100 mA output capability, 0.2 V typical dropout at full load, and 50 µA quiescent current in OFF mode - designed for battery-powered sensor nodes and low-noise analog front-ends in industrial IoT edge devices.

For engineers reviewing the LE33CZ-TR datasheet, LE33CZ-TR pinout, LE33CZ-TR application, or LE33CZ-TR equivalent, this device supports precise local regulation where thermal efficiency, standby power minimization, and minimal external capacitance (2.2 µF) are critical selection criteria.

Technical Context

The LE33CZ-TR implements a PNP-based LDO architecture with internal current and thermal limiting, enabling stable operation across –40 °C to +125 °C junction temperature. Its inhibit function is inactive in TO-92 configuration, resulting in fixed ON-state operation without control logic.

It achieves 80 dB supply voltage rejection at 120 Hz and maintains 50 µV RMS output noise (10 Hz–100 kHz), making it suitable for powering precision ADCs, op-amps, and RF bias rails where PSRR and noise floor directly impact signal integrity.

Key Specifications

Pinout & Package

LE33CZ-TR uses the standard TO-92 through-hole package (3-pin, straight lead configuration). Pin 1 = Input (IN), Pin 2 = Ground (GND), Pin 3 = Output (OUT). No inhibit pin is present - device operates permanently in ON state.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with LD33CVTR and LP2951ACMX-3.3, LE33CZ-TR offers lowest dropout and simplest implementation (TO-92, no control lines), but trades off programmability and thermal safety margin - ideal for cost-sensitive, space-constrained, always-on applications.

Availability

LE33CZ-TR is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, automotive cabin controllers, and smart meter data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LE33CZ-TR 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 analog products for industrial, automotive, and consumer markets.

This device belongs to the LEXX family of very low-dropout regulators, engineered specifically for ultra-low-power, high-accuracy local regulation in battery-operated and thermally constrained embedded systems.

FAQ

Is LE33CZ-TR pin-compatible with the L78L series?

Yes - LE33CZ-TR is pin-to-pin compatible with the L78L33 in TO-92 package, offering identical pinout (IN-GND-OUT) and mechanical footprint. It improves upon L78L33 with lower dropout (0.2 V vs. ~1.7 V), lower quiescent current (50 µA vs. ~5.5 mA), and tighter output tolerance (±2% vs. ±5%).

Does LE33CZ-TR have an enable/inhibit function in TO-92 package?

No - the inhibit function is only implemented in the SO-8 variant (e.g., LE33CD-TR, pin 5). The TO-92 version (LE33CZ-TR) has no inhibit pin and operates continuously in ON mode. Leaving the inhibit pin unconnected is not applicable here due to missing terminal.

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

The minimum input voltage is 3.5 V: output is 3.3 V, and typical dropout is 0.2 V at 100 mA. At worst-case conditions (–40 °C to +125 °C), dropout rises to 0.5 V, requiring ≥3.8 V input to sustain regulation. Input must remain ≤18 V per absolute maximum rating.

Can LE33CZ-TR be used with ceramic capacitors only?

Yes - the device is stable with a single 2.2 µF X7R or X5R ceramic capacitor (ESR 0.1–10 Ω) on the output. No tantalum or aluminum electrolytic capacitor is needed. Input capacitance of 0.1 µF ceramic is recommended but not mandatory for basic operation.