STMicroelectronics LDK120M30R

Overview

LDK120M30R from STMicroelectronics is a 200 mA, 3.0 V fixed-output low-dropout (LDO) regulator with 100 mV typical dropout at 100 mA, 100 µA max quiescent current, ±2.0% output voltage tolerance at 25 °C, and operation from 1.9 V to 5.5 V input. It delivers ultra-low noise (51 µV_RMS, 10 Hz–100 kHz with 10 nF bypass) and logic-controlled shutdown (<1 µA OFF-mode current), targeting power rails for RF-sensitive analog circuitry in portable battery-powered systems.

For engineers reviewing the LDK120M30R datasheet, LDK120M30R pinout, LDK120M30R application, or LDK120M30R equivalent, key selection criteria include dropout performance under 200 mA load, ceramic-capacitor stability (1 µF C_OUT), thermal shutdown threshold (160 °C), enable logic thresholds (0.4 V low / 1.2 V high), and package-specific thermal resistance (SOT23-5L: R_thJA = 160 °C/W).

Technical Context

The LDK120M30R employs a PMOS pass transistor architecture enabling ultra-low dropout and near-zero gate-drive current, eliminating external bias requirements. Its internal bandgap reference and error amplifier maintain tight output regulation across –40 °C to 125 °C junction temperature while supporting fast load transient response (≤50 µs recovery for 1 mA ↔ 200 mA step).

It integrates logic-compatible enable control (VEN referenced to VIN), internal short-circuit current limiting (~400 mA), and thermal foldback protection. The fixed 3.0 V version uses an internal resistor divider; no external feedback components are required, and the ADJ/BYP pin is NC (not connected) and must be left floating or tied to GND per package variant.

Key Specifications

Pinout & Package

LDK120M30R is packaged in SOT23-5L - a 5-pin, surface-mount plastic package (2.95 mm × 1.60 mm × 1.45 mm) with exposed thermal pad not present; suitable for automated assembly and moderate power dissipation (R_thJA = 160 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B302MR-G and ADP160AUJZ-3.0-R7, the LDK120M30R uniquely balances 200 mA drive capability, 100 mV dropout, 51 µV_RMS noise, integrated thermal shutdown, and active-high enable-all in a 5-pin SOT23 package-making it optimal for thermally constrained, noise-sensitive, battery-powered applications requiring robust autonomy.

Availability

LDK120M30R is available at Aetrix Electronics and suitable for mobile phone RF modules, digital camera sensor bias rails, wearable health monitor analog subsystems, and industrial IoT edge node MCUs requiring stable component supply across extended temperature and lifecycle demands.

Supply support for LDK120M30R 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 automotive, industrial, and consumer markets.

The LDK120 series is part of ST's precision low-noise LDO portfolio, engineered specifically for battery-powered portable electronics demanding ultra-low quiescent current, minimal output noise, and robust protection in miniature packages.

FAQ

What is the minimum input voltage required for stable 3.0 V output at 200 mA load?

The LDK120M30R requires VIN ≥ 3.3 V to guarantee 3.0 V output at 200 mA, based on its maximum dropout voltage of 300 mV (typ. 150 mV) under those conditions. At 100 mA, VIN ≥ 3.1 V suffices. Input below these thresholds causes output collapse or regulation loss.

Can the BYP/ADJ pin be left unconnected on the LDK120M30R?

Yes-the BYP/ADJ pin is internally not connected (NC) on fixed-output versions like LDK120M30R. It must be left floating with no PCB trace or pad; connecting it to any potential (including GND) is permissible per datasheet Table 1 but provides no functional benefit and may increase leakage paths.

Does the LDK120M30R require an input capacitor?

Yes-a 1 µF ceramic capacitor (X5R/X7R) is required between IN and GND, placed within 2 mm of the pins. This stabilizes the internal control loop and suppresses high-frequency noise from upstream sources; omission risks oscillation or degraded transient response.

How does thermal performance differ between SOT23-5L and DFN6 packages?

SOT23-5L has R_thJA = 160 °C/W, while DFN6 (1.2 × 1.3 mm) achieves 237 °C/W-meaning the SOT23-5L dissipates heat more effectively on standard 2-layer PCBs. For 200 mA at 3.0 V output with 3.5 V input (0.5 V drop → 100 mW power), SOT23-5L rises ~16 °C above ambient versus ~24 °C for DFN6 under identical layout conditions.