STMicroelectronics LDK220C27R

Overview

LDK220C27R from STMicroelectronics is a fixed-output 2.7 V, 200 mA low-dropout linear regulator in SOT323-5L package. It delivers ultra-low dropout (100 mV typ. @ 100 mA), 55 µA quiescent current, ±2.0% output voltage accuracy at 25 °C, and operates from 2.5 V to 13.2 V input. Designed for space-constrained battery-powered systems requiring stable low-noise supply.

For engineers reviewing the LDK220C27R datasheet, LDK220C27R pinout, LDK220C27R application, or LDK220C27R equivalent, key selection criteria include dropout performance at 200 mA load, enable-controlled shutdown (<1 µA off-state), ceramic capacitor compatibility (1 µF COUT), thermal protection behavior, and package-specific pin mapping across SOT323-5L/SOT23-5L/DFN6 variants.

Technical Context

The LDK220C27R integrates a bandgap reference, error amplifier, and PMOS pass transistor with internal current and thermal limiting. Its enable-controlled shutdown disables regulation and activates an 18 Ω internal discharge path on VOUT when EN is low - a feature absent in SOT-89 variants.

It supports both fixed-output (2.7 V) and adjustable versions via ADJ pin; the C27R suffix confirms fixed 2.7 V output in SOT323-5L. Input voltage range (2.5–13.2 V), 160 °C thermal shutdown with 20 °C hysteresis, and 55 dB SVR at 120 Hz–1 kHz define its robustness in noisy, thermally variable environments.

Key Specifications

Pinout & Package

LDK220C27R is packaged in SOT323-5L: a 1.8 × 2.0 mm, 5-pin surface-mount package with exposed pad for thermal enhancement. Pin 1 = IN, Pin 2 = GND, Pin 3 = EN, Pin 4 = ADJ/NC (not connected in fixed version), Pin 5 = OUT.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, enable-controlled LDO applications.

Compared with LDK220C27R, the M27R offers superior thermal performance in compact designs needing higher power handling, while PU27R trades control flexibility for lower BOM count and cost - making C27R optimal for space-constrained, enable-driven battery systems.

Availability

LDK220C27R is available at Aetrix Electronics and suitable for battery-powered medical wearables, set-top box auxiliary rails, and industrial I/O modules requiring stable component supply with guaranteed 200 mA output and ultra-low quiescent current.

Supply support for LDK220C27R 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LDK220 series belongs to ST's high-efficiency, low-noise LDO portfolio targeting portable and energy-sensitive applications - engineered specifically for extended battery life, small form factor, and robust operation across wide temperature ranges.

FAQ

What is the minimum input voltage required for LDK220C27R to maintain regulation at 200 mA load?

The dropout voltage is 350 mV maximum at 200 mA and 125 °C (per Table 6). To sustain 2.7 V output, VIN must be ≥ 3.05 V under worst-case thermal conditions. At room temperature, 2.8 V input suffices due to 200 mV typical dropout at 200 mA.

Can LDK220C27R be used with a 10 µF X5R ceramic capacitor on the output?

Yes - the device is stable with 1–22 µF ceramic capacitors (Table 6), including 10 µF X5R. ESR must remain below 1 Ω across frequency; X5R types typically meet this. No series resistance or damping is required.

Is the ADJ pin accessible or usable on the LDK220C27R variant?

No - the "C" prefix and "27R" suffix denote the fixed 2.7 V output version in SOT323-5L. Pin 4 is labeled ADJ/NC and is internally disconnected; it must be left floating or tied to GND (not recommended) but never driven or loaded.

Does LDK220C27R provide reverse-current blocking when EN is low?

No - the device does not block reverse current from VOUT to IN. However, when EN is low, the internal 18 Ω discharge path actively pulls VOUT toward GND, preventing back-powering of upstream sources and ensuring safe power-down sequencing.