STMicroelectronics LE30CD-TR

Overview

LE30CD-TR from STMicroelectronics is a very low-dropout (LDO) linear voltage regulator delivering 3.0 V at up to 100 mA output current in SO-8 package with TTL-compatible inhibit control (pin 5). It features 0.2 V typical dropout, 50 µA quiescent current in OFF mode, ±2% output voltage accuracy at 25 °C, and operates across –40 to 125 °C for automotive and industrial power management.

For engineers reviewing the LE30CD-TR datasheet, LE30CD-TR pinout, LE30CD-TR application, or LE30CD-TR equivalent, this device serves as a precision local regulator in battery-powered systems requiring standby-mode power gating, low-noise analog supply, and stable 3 V rail generation under wide input (up to 18 V) and load conditions.

Technical Context

The LE30CD-TR implements an internal PNP pass transistor architecture enabling ultra-low dropout and high PSRR (81 dB at 120 Hz). Its inhibit function uses a dedicated TTL-compatible logic input (pin 5) that pulls the regulator into sub-50 µA shutdown state when driven low - no external pull-down required.

Stability is achieved with only a 2.2 µF ceramic output capacitor (ESR 0.1–10 Ω), eliminating need for large electrolytics. Internal thermal and current limiting protect against fault conditions without external components, and the SO-8 package integrates pins 2/3/6/7 to the die attach pad for enhanced thermal dissipation (R_thJA = 55 °C/W).

Key Specifications

Pinout & Package

LE30CD-TR is supplied in an SO-8 package (ECOPACK® compliant) with pins 2, 3, 6, and 7 internally fused to the exposed die attach pad for improved thermal performance. The package footprint matches standard SO-8 but delivers lower R_thJA (55 °C/W) due to enhanced copper thermal path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LDL113PU33R and MCP1702T-3002E/MB, LE30CD-TR uniquely balances 3.0 V output, 0.2 V dropout, and 50 µA shutdown current - making it optimal for 3 V systems operating near battery end-of-life or requiring precise voltage matching without sacrificing thermal robustness.

Availability

LE30CD-TR is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, medical wearables, and smart metering applications requiring stable component supply, extended temperature support, and reliable inhibit-controlled power sequencing.

Supply support for LE30CD-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 systems needing precision LDOs with integrated inhibit control and extended temperature operation - targeting automotive ECUs, industrial controllers, and battery-constrained IoT endpoints.

FAQ

What is the minimum input voltage required for LE30CD-TR to maintain regulation at full 100 mA load?

The minimum input voltage is calculated as V_OUT + V_DROP = 3.0 V + 0.4 V (max dropout at 100 mA) = 3.4 V. At 25 °C, typical dropout is 0.2 V, so 3.2 V input sustains regulation. Operation below 3.4 V is valid only if junction temperature remains ≤85 °C and load ≤100 mA.

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

Yes, the INH pin may float, and the device defaults to ON mode per internal pull-up. However, ST recommends grounding INH when unused to prevent noise-induced toggling. Floating operation is functional but risks unintended shutdown in high-noise environments such as automotive harnesses or motor-driven systems.

Is LE30CD-TR pin-to-pin compatible with the L78L33ACZ-TR?

No - LE30CD-TR is pin-to-pin compatible with the L78L series *only in TO-92 configuration*. In SO-8, LE30CD-TR uses an 8-pin layout with dedicated INH (pin 5) and multiple GND pins (2,6,7,8), whereas L78L33ACZ-TR in SO-8 has standard 3-pin mapping (IN, GND, OUT) with no inhibit function. Direct replacement requires PCB redesign.

What is the maximum allowable output capacitance for stable operation?

The datasheet specifies CO = 2.2 µF (min) with ESR 0.1–10 Ω for guaranteed stability. While larger values (up to 10 µF) are permitted per Table 4, exceeding 2.2 µF does not improve transient response and may increase start-up time. Ceramic capacitors ≥2.2 µF with X7R dielectric and ESR within spec ensure optimal phase margin across –40 to 125 °C.