STMicroelectronics LDK120M08R

Overview

LDK120M08R from STMicroelectronics is a 200 mA, 0.8 V fixed-output low-dropout (LDO) regulator in SOT23-5L package, featuring 100 mV typical dropout at 100 mA, ±2.0% output voltage tolerance at 25 °C, and 100 µA max quiescent current. 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), optimized for space-constrained, battery-powered systems requiring stable low-voltage rail generation.

For engineers reviewing the LDK120M08R datasheet, LDK120M08R pinout, LDK120M08R application, or LDK120M08R equivalent, key selection criteria include its 0.8 V fixed output, SOT23-5L footprint compatibility, ceramic-capacitor stability (C_OUT = 1 µF), thermal/short-circuit protection, and operation across –40 °C to 125 °C junction temperature.

Technical Context

The LDK120M08R implements a PMOS pass transistor architecture enabling ultra-low dropout and minimal quiescent current across load and temperature. Its internal reference and error amplifier maintain tight output regulation under dynamic line (0.05 %/V) and load (0.006 %/mA) variations, while the dedicated BYP pin supports optional 10 nF capacitor for noise reduction - critical for RF and precision analog subsystems.

Enable control is TTL/CMOS-compatible (V_ENIL ≤ 0.4 V, V_ENIH ≥ 1.2 V), allowing direct interfacing with microcontrollers without level-shifting. Integrated thermal shutdown (160 °C, 20 °C hysteresis) and constant-current short-circuit limiting (400 mA typ.) ensure robust fault handling in portable and embedded power rails.

Key Specifications

Pinout & Package

LDK120M08R is packaged in SOT23-5L - a 2.95 mm × 1.60 mm surface-mount package with 0.95 mm pitch, suitable for high-density PCB layouts and automated assembly. Thermal resistance is R_thJA = 160 °C/W, enabling >150 mW power dissipation at ambient 85 °C with minimal copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B082MR-G and RT9013-08GB, LDK120M08R uniquely combines 100 mV dropout, 51 µV_RMS noise with BYP option, and <1 µA shutdown - making it the only choice for battery-powered systems demanding simultaneous ultra-low voltage, ultra-low noise, and ultra-low quiescent current.

Availability

LDK120M08R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, wearable health monitors, and industrial wireless sensor nodes requiring stable component supply across extended temperature and long product lifecycles.

Supply support for LDK120M08R 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 LDK120 series was developed specifically for ultra-low-power, low-noise portable electronics - targeting battery-operated devices where efficiency, size, and signal integrity are non-negotiable design constraints.

FAQ

What is the minimum input voltage required for LDK120M08R to regulate 0.8 V output at 200 mA?

The minimum input voltage equals the output voltage plus the maximum dropout voltage under that load. At 200 mA and 40–125 °C, dropout is 300 mV max per datasheet Table 4. Therefore, minimum VIN = 0.8 V + 0.3 V = 1.1 V. However, the absolute minimum specified operating VIN is 1.9 V - this ensures guaranteed performance across all conditions including line/load regulation and thermal stability.

Can LDK120M08R be used with a 10 µF ceramic output capacitor?

Yes - the datasheet specifies C_OUT stability range from 1 µF to 22 µF (Figure 25). A 10 µF X5R/X7R ceramic capacitor falls well within this region and improves load-transient response without risking instability. Ensure ESR remains below 7 Ω at 100 kHz per the stability plot's recommended region.

Is the BYP pin mandatory for LDK120M08R operation?

No - the BYP pin is optional. When unused, it must be left floating with no PCB routing, as stated in Table 1. The device operates fully functional without it. Adding a 10 nF capacitor between BYP and GND reduces output noise from 148 µV_RMS to 51 µV_RMS, but is only required in noise-sensitive applications like RF or high-resolution ADC supplies.

Does LDK120M08R support reverse polarity protection on the IN pin?

No - the device lacks integrated reverse-voltage protection. Applying negative voltage to IN relative to GND violates the absolute maximum rating of –0.3 V (Table 2) and may cause permanent damage. External protection - such as a series Schottky diode or ideal diode controller - must be added if reverse polarity exposure is possible in the system.