STMicroelectronics LDK120M28R

Overview

LDK120M28R from STMicroelectronics is a 200 mA, 2.8 V fixed-output low-dropout linear 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 - designed for power management in space-constrained, battery-powered portable electronics.

For engineers reviewing the LDK120M28R datasheet, LDK120M28R pinout, LDK120M28R application, or LDK120M28R equivalent, this page delivers verified electrical specs, package-validated pin functions, real-world use cases in mobile and imaging systems, and cross-manufacturer alternatives with documented functional trade-offs.

Technical Context

The LDK120M28R employs a PMOS pass transistor architecture enabling ultra-low dropout and stable regulation with only 1 µF ceramic output capacitance. Its internal bandgap reference and error amplifier deliver tight load/line regulation (0.006 %/mA and 0.05 %/V) across –40 °C to 125 °C.

Logic-controlled enable (EN) pin supports active-high operation with 0.4 V logic-low threshold and 1.2 V logic-high threshold, allowing sub-1 µA shutdown current. Integrated thermal shutdown (160 °C) and short-circuit current limiting (400 mA typ.) provide robust fault protection without external components.

Key Specifications

Pinout & Package

LDK120M28R is available in SOT23-5L (2.9 mm × 1.6 mm × 1.45 mm) - a compact, surface-mount package with exposed thermal pad (not electrically connected) optimized for high-density PCB layouts and thermal dissipation in portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P282MR and ADP160ACBZ-2.8-R7, the LDK120M28R uniquely balances 200 mA drive, 100 mV dropout, 125 °C operation, and 51 µV_RMS noise - making it optimal for thermally demanding, battery-critical portable imaging and communication systems.

Availability

LDK120M28R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, cordless phone base stations, and industrial handheld displays requiring stable component supply with long-term lifecycle assurance.

Supply support for LDK120M28R 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 delivery in portable and battery-operated equipment.

FAQ

What is the minimum input voltage required for stable 2.8 V output at 200 mA load?

The LDK120M28R maintains regulation down to VIN = VOUT + VDROP. At 200 mA and 125 °C, max dropout is 300 mV per Table 4 - so minimum input is 3.1 V. At room temperature, 150 mV dropout applies, allowing stable operation from 2.95 V input.

Can the BYP pin be left unconnected in the fixed 2.8 V version?

Yes. Per Table 1, the BYP pin on fixed-output versions is optional for noise reduction: if unused, it must be left floating with no PCB routing or termination - neither grounded nor pulled. Adding a 10 nF ceramic capacitor reduces output noise from 148 µV_RMS to 51 µV_RMS.

Is the SOT23-5L package RoHS-compliant and halogen-free?

Yes. STMicroelectronics certifies the LDK120M28R in SOT23-5L as ECOPACK2-compliant - meeting RoHS Directive 2011/65/EU and halogen-free requirements (IEC 61249-2-21), with lead-free matte tin terminations and green molding compound.

Does the LDK120M28R require an external resistor divider for output voltage setting?

No. The LDK120M28R is a fixed-output variant - its 2.8 V regulation is achieved internally via laser-trimmed feedback. Only the adjustable "D" versions (e.g., LDK120M-R) use external R1/R2 dividers; those pins are repurposed as BYP or NC on fixed variants.