STMicroelectronics LDK120M11R

Overview

LDK120M11R from STMicroelectronics is a 200 mA, 1.1 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), targeting power rails in portable battery-powered systems.

For engineers reviewing the LDK120M11R datasheet, LDK120M11R pinout, LDK120M11R application, or LDK120M11R equivalent, key selection criteria include its 1.1 V fixed output, SOT23-5L package compatibility with 1 µF ceramic output capacitance, thermal shutdown (160 °C), and enable-controlled low-power sequencing in space-constrained mobile devices.

Technical Context

The LDK120M11R employs a PMOS pass transistor architecture enabling ultra-low dropout and stable regulation down to 1.9 V input-critical for single-cell Li-ion and Li-polymer battery systems. Its internal bandgap reference and error amplifier maintain tight output accuracy across -40 °C to 125 °C junction temperature.

It integrates logic-level enable control (V_EN high = active, low = shutdown), internal short-circuit current limiting (~400 mA), and thermal foldback protection. The device is optimized for use with 1 µF ceramic C_OUT, eliminating need for electrolytic or tantalum capacitors.

Key Specifications

Pinout & Package

LDK120M11R is packaged in SOT23-5L (2.95 mm × 1.60 mm × 1.45 mm), a surface-mount 5-pin package with exposed thermal pad (not electrically connected). Pin 5 is OUT; Pin 1 is IN; Pin 2 is GND; Pin 3 is EN; Pin 4 is BYP (bypass capacitor connection for noise reduction, optional on fixed versions).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B112MR-G and RT9013-11GB, LDK120M11R uniquely balances ultra-low noise (51 µV_RMS), enable control, and 200 mA capability in SOT23-5L-making it optimal for mixed-signal portable systems where both power efficiency and signal integrity are critical.

Availability

LDK120M11R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, wearable health monitors, and Bluetooth LE audio devices requiring stable component supply with full production lifecycle support through July 2026.

Supply support for LDK120M11R 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 belongs to ST's high-performance analog LDO portfolio, engineered specifically for ultra-low-noise, low-quiescent-current power management in space-constrained, battery-operated portable electronics.

FAQ

What is the minimum input voltage required for LDK120M11R to regulate 1.1 V output?

The LDK120M11R requires a minimum input voltage of 1.9 V to maintain regulation. At 100 mA load, its typical dropout is 100 mV, so 1.2 V input would be insufficient; 1.9 V ensures stable operation across temperature, load, and process variation per datasheet Section 4 maximum ratings and Table 4 electrical characteristics.

Can LDK120M11R operate with a 1 µF ceramic output capacitor only-no bypass capacitor?

Yes. LDK120M11R is stable with a single 1 µF ceramic C_OUT (X5R/X7R) as specified in Section 3 typical application and Table 4. The BYP pin (Pin 4) is optional: omitting the 10 nF bypass capacitor increases output noise to 148 µV_RMS (Table 4 footnote 2), but does not affect stability or regulation.

Is thermal shutdown latched or auto-recovering?

Thermal shutdown is auto-recovering. When junction temperature reaches 160 °C (T_SHDN), the device disables output and enters thermal foldback. Once temperature drops by ~20 °C hysteresis (Section 4, Table 2), regulation resumes automatically without external intervention or power cycle.

Does LDK120M11R support reverse current blocking?

No. LDK120M11R does not integrate reverse current blocking. With IN < OUT (e.g., during input removal while output remains charged), body diode conduction in the PMOS pass device allows reverse current flow. External reverse-blocking diodes or MOSFETs are required in systems where backfeed must be prevented.