STMicroelectronics LDK120M10R

Overview

LDK120M10R from STMicroelectronics is a 1.0 V fixed-output, 200 mA low-dropout linear regulator with 100 µA max quiescent current, 100 mV typical dropout at 100 mA, ±2.0% output voltage tolerance at 25 °C, and operation from 1.9 V to 5.5 V input. It features logic-controlled shutdown (EN pin), ceramic capacitor compatibility (1 µF COUT), and thermal/short-circuit protection - deployed in battery-powered mobile phones and digital still cameras for stable low-noise core rail regulation.

For engineers reviewing the LDK120M10R datasheet, LDK120M10R pinout, LDK120M10R application, or LDK120M10R equivalent, key selection considerations include dropout performance at 200 mA load, sub-1 µA shutdown current, noise sensitivity in RF-adjacent subsystems, and SOT23-5L package thermal resistance (160 °C/W) for compact portable designs.

Technical Context

The LDK120M10R implements a PMOS pass transistor architecture enabling ultra-low dropout and minimal quiescent current across temperature. Its internal reference and error amplifier maintain tight output regulation under dynamic load steps up to 200 mA while rejecting supply ripple via 55 dB SVR from 120 Hz to 10 kHz.

Enable control is TTL/CMOS-compatible with logic-low shutdown (<0.4 V) and logic-high activation (>1.2 V), and the device integrates foldback current limiting and thermal shutdown at 160 °C with 20 °C hysteresis - eliminating external protection circuitry in space-constrained applications.

Key Specifications

Pinout & Package

LDK120M10R is packaged in SOT23-5L (1.45 mm × 2.95 mm × 1.30 mm), a surface-mount 5-pin plastic package with exposed thermal pad (not electrically connected). Thermal resistance is R_thJA = 160 °C/W, supporting 200 mA continuous operation in ambient up to 85 °C with minimal PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B102MR-G and RT9193-10GB, LDK120M10R uniquely balances 200 mA delivery, 100 mV dropout, integrated thermal protection, and 148 µVRMS noise - making it optimal for thermally constrained, noise-sensitive 1.0 V rails where both performance and safety are non-negotiable.

Availability

LDK120M10R is available at Aetrix Electronics and suitable for mobile phone baseband power, digital still camera sensor rails, portable medical pulse oximeters, and industrial handheld terminals requiring stable component supply across extended temperature and long production lifecycles.

Supply support for LDK120M10R 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 analog devices for automotive, industrial, and consumer markets.

LDK120M10R belongs to ST's LDK120 ultra-low-noise LDO family, engineered specifically for battery-powered portable electronics demanding high PSRR, sub-100 µA quiescent current, and ceramic-capacitor stability in miniature packages.

FAQ

What is the minimum input voltage required for LDK120M10R to regulate 1.0 V output at 200 mA?

The dropout voltage is 300 mV maximum at 200 mA and 40–125 °C per datasheet Table 4. Therefore, minimum input voltage is 1.0 V + 0.3 V = 1.3 V. At room temperature and 100 mA, typical dropout is 100 mV, allowing regulation down to 1.1 V input - but design margin requires using the 300 mV worst-case value for full-load operation.

Can LDK120M10R be used with a 0.47 µF output capacitor?

No. The datasheet specifies 1 µF minimum ceramic output capacitance (X5R/X7R) for stability across all operating conditions. Using 0.47 µF violates the stability region shown in Figure 25 and risks oscillation, especially under load transients. ST validates performance only with ≥1 µF COUT and ESR <1 Ω at 100 kHz.

Is the BYP pin on LDK120M10R required to be connected?

No. For fixed-output versions like LDK120M10R, Pin 4 (BYP/NC) is internally not connected and must be left floating - no routing, no capacitor, no pull-up/down. Connecting it may cause unpredictable behavior. This differs from adjustable versions where Pin 4 serves as ADJ.

Does LDK120M10R support reverse current protection?

No. The LDK120M10R does not integrate reverse current blocking. When input falls below output (e.g., during hot-swap or backup battery switchover), current can flow backward from OUT to IN through the PMOS pass device body diode. External reverse-blocking MOSFET or diode is required if reverse current must be prevented.