STMicroelectronics LE25CD

Overview

LE25CD from STMicroelectronics is a very low dropout (LDO) linear voltage regulator delivering 2.5 V output at up to 100 mA, with typical dropout voltage of 0.2 V at full load and quiescent current of 50 µA in OFF mode. It features TTL-compatible inhibit control (pin 5 in SO-8), ±2 % output voltage accuracy at 25 °C, and operates across –40 to 125 °C for use in battery-powered sensor nodes and automotive body electronics.

For engineers reviewing the LE25CD datasheet, LE25CD pinout, LE25CD application, or LE25CD equivalent, this device is selected for ultra-low-power local regulation where standby current, thermal efficiency in compact layouts, and input-to-output headroom below 0.5 V are critical design constraints.

Technical Context

The LE25CD implements a PNP-based pass transistor architecture enabling sub-0.3 V dropout at 100 mA while maintaining stability with only 2.2 µF ceramic output capacitance. Its internal current and thermal limiting protect against overload and junction overheating under sustained high ambient conditions.

Inhibit logic is integrated directly into the control loop: applying <0.8 V to the INH pin forces shutdown (50 µA IQ), while ≥2 V enables regulation. The SO-8 package uses pins 2, 3, 6, and 7 internally connected to the die attach flag for enhanced thermal dissipation (R_thJA = 55 °C/W).

Key Specifications

Pinout & Package

LE25CD is available in SO-8 package (ECOPACK® compliant) with exposed die attach flag for thermal enhancement. Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN, Pin 4 = GND, Pin 5 = INH (inhibit), Pin 6 = GND, Pin 7 = GND, Pin 8 = NC (no connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDK220M25 and TS2937CZ25, LE25CD uniquely balances ultra-low OFF-mode IQ (50 µA), integrated inhibit logic, and SO-8 thermal performance-making it optimal for battery-backed or thermally constrained embedded systems requiring precise 2.5 V regulation with dynamic power gating.

Availability

LE25CD is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, medical wearables, and smart energy metering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LE25CD 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 automotive-grade components since 1987.

The LE series LDO regulators were developed specifically for ultra-low-power, high-reliability embedded systems in automotive and industrial markets where thermal efficiency, small footprint, and precise voltage accuracy are mandatory.

FAQ

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

The LE25CD maintains regulation as long as input voltage exceeds output voltage by its dropout voltage. At 100 mA and 25 °C, typical dropout is 0.2 V, so minimum input is 2.7 V. At –40 to 125 °C, max dropout is 0.5 V, requiring ≥3.0 V input for guaranteed regulation across temperature.

Can the INH pin be left floating, and what happens if it is?

No - the INH pin must not be left floating. Per datasheet Note in Section 3, an unconnected INH pin may pick up noise and cause erratic ON/OFF behavior. When inhibit functionality is unused, STMicroelectronics specifies grounding the pin to ensure stable ON-state operation and prevent unintended shutdown.

Is the 2.2 µF output capacitor value absolute, or can larger values be used?

A 2.2 µF ceramic capacitor is the minimum required for stability per test conditions in Tables 5 and 6. Larger values (up to 10 µF) are explicitly permitted and improve transient response and PSRR, but do not degrade stability. ESR must remain between 0.1 Ω and 10 Ω - avoid low-ESR polymer or tantalum unless verified with manufacturer SPICE models.

How does the SO-8 thermal performance compare to TO-92 for LE25CD?

The SO-8 package achieves R_thJA = 55 °C/W with standard PCB layout (1 cm² copper), while TO-92 is rated at 200 °C/W. This means SO-8 delivers ~3.6× better thermal dissipation - enabling 100 mA continuous output at 85 °C ambient versus ≤25 mA for TO-92. The SO-8's internal flag connection to pins 2/3/6/7 is key to this advantage.