STMicroelectronics LE50CD-TR

Overview

LE50CD-TR from STMicroelectronics is a very low-dropout (LDO) linear voltage regulator delivering 5 V ±2% output at up to 100 mA, featuring 0.2 V typical dropout voltage, 50 µA OFF-mode quiescent current, and TTL-compatible inhibit control (pin 5) in SO-8 package. It operates across –40 °C to 125 °C and supports stable regulation with only a 2.2 µF output capacitor - ideal for space-constrained, battery-powered microcontroller subsystems.

For engineers reviewing the LE50CD-TR datasheet, LE50CD-TR pinout, LE50CD-TR application, or LE50CD-TR equivalent, key selection criteria include dropout performance under 100 mA load, shutdown logic compatibility, thermal resistance (R_thJA = 55 °C/W), and ±2% output tolerance at 25 °C - all critical for low-power embedded power rail design.

Technical Context

The LE50CD-TR implements a PNP-based LDO architecture with internal current and thermal limiting, enabling robust operation without external protection circuitry. Its inhibit function accepts TTL-level logic (V_IL ≤ 0.8 V, V_IH ≥ 2 V) on pin 5 to disable output and reduce quiescent current to 50 µA - essential for system-level power gating.

Stability is achieved with a minimum 2.2 µF ceramic output capacitor (ESR 0.1–10 Ω), eliminating need for larger electrolytics. Supply voltage rejection reaches 76 dB at 1 kHz, and output noise is specified at 50 µV RMS (10 Hz–100 kHz), supporting noise-sensitive analog and RF subsystems.

Key Specifications

Pinout & Package

LE50CD-TR is supplied in an SO-8 surface-mount package with exposed die attach pad fused to pins 2, 3, 6, and 7 for enhanced thermal conduction. The package conforms to standard SO-8 mechanical dimensions (D = 4.9 mm, E = 6.0 mm, e = 1.27 mm pitch) and supports reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDK320M50R and TLV70550YFPR, LE50CD-TR uniquely combines integrated inhibit control, thermal/current protection, and SO-8 thermal performance - making it optimal for automotive and industrial designs requiring robustness and system-level power sequencing.

Availability

LE50CD-TR is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, medical wearables, and smart home controllers requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.

Supply support for LE50CD-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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The LEXX series was developed specifically for low-power, high-reliability embedded applications demanding ultra-low dropout, precise output tolerance, and integrated power management - targeting automotive sub-systems and industrial edge devices.

FAQ

What is the minimum input voltage required for stable 5 V output at 100 mA?

The LE50CD-TR requires a minimum input voltage of 5.2 V to maintain regulation at 100 mA load, based on its 0.2 V typical dropout voltage. At worst-case conditions (T_J = 125 °C), dropout rises to 0.5 V, so 5.5 V input ensures margin. Input must remain within 5.7–18 V absolute maximum ratings.

Can the INHIBIT pin be left unconnected?

No - leaving the INHIBIT pin floating places the device in ON mode but risks noise-induced toggling. ST recommends tying it directly to GND if shutdown functionality is unused, or driving it with a clean TTL-level signal (≤0.8 V for OFF, ≥2 V for ON) when active control is needed.

Is an input bypass capacitor required?

Yes - a minimum 0.1 µF ceramic capacitor must be placed between IN and GND, as close as possible to pins 1 and 2/3/6/7. This stabilizes the input supply and prevents oscillation due to source impedance, especially when powered from long traces or switching regulators.

How does the SO-8 thermal design differ from standard SO-8 packages?

The LE50CD-TR's SO-8 uses an internally modified leadframe where pins 2, 3, 6, and 7 are electrically fused to the die attach pad, reducing R_thJC to 20 °C/W. This requires connecting those pins to a large PCB copper area to achieve the rated 55 °C/W R_thJA - unlike standard SO-8, where only the exposed pad conducts heat.