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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics LDK320M25R

Name: LDK320M25R
Brand: STMicroelectronics
SKU: LDK320M25R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LDK320M25R

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: SC-74A, SOT-753

Datasheet:: LDK320M25R.pdf

Description:: IC REG LINEAR 2.5V 200MA SOT23-5

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Product details

Overview

LDK320M25R from STMicroelectronics is a 2.5 V fixed-output, 200 mA low-dropout linear regulator in SOT-89 package, featuring 100 mV typical dropout at 100 mA, ±2% output voltage accuracy over –40 °C to 125 °C, and 88 dB PSRR at 120 Hz. It supports logic-controlled shutdown (I_OFF < 1 μA), operates from 2.5 V to 18 V input, and is stabilized with 1 μF ceramic output capacitor - ideal for space-constrained industrial power rails and battery-powered DSC/BD systems.

For engineers reviewing the LDK320M25R datasheet, LDK320M25R pinout, LDK320M25R application, or LDK320M25R equivalent, key selection criteria include dropout performance under 200 mA load, thermal shutdown behavior at 160 °C, compatibility with low-ESR ceramic capacitors, and enable logic thresholds (V_ENL = 0.4 V, V_ENH = 1.2 V) across full temperature range.

Technical Context

The LDK320M25R implements a bandgap-referenced op-amp control loop with internal current limiting, SOA protection, and thermal shutdown with 20 °C hysteresis. Its architecture enables stable regulation with only 1 μF ceramic C_OUT, eliminating need for electrolytic or tantalum capacitors.

It delivers 2.5 V output with ±2% tolerance over –40 °C to 125 °C junction temperature, maintains 60 μA typical quiescent current at no load, and achieves 63 μV_RMS integrated output noise (10 Hz–100 kHz) - critical for powering analog front-ends and low-noise sensor interfaces.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.5 V ±2% at 25 °C; ±3% over –40 °C to 125 °C - ensures stable MCU core or interface rail under thermal stress.
Max Output Current	200 mA continuous - sufficient for powering single-core microcontrollers, display drivers, or small FPGA I/O banks.
Dropout Voltage	100 mV typ. @ 100 mA, 200–350 mV max @ 200 mA - enables operation from 2.75 V input while maintaining 2.5 V output.
PSRR	88 dB @ 120 Hz, 65 dB @ 1 kHz - suppresses ripple from noisy DC-DC pre-regulators feeding sensitive analog circuits.
Quiescent Current	60 μA typ. active, 0.2–1 μA in shutdown - extends battery life in always-on monitoring nodes.
Enable Thresholds	V_ENL ≤ 0.4 V (shutdown), V_ENH ≥ 1.2 V (active) - compatible with 1.8 V/3.3 V GPIO without level-shifting.
Thermal Shutdown	160 °C with 20 °C hysteresis - prevents permanent damage during sustained overload or poor PCB heatsinking.

Pinout & Package

SOT-89 package (D configuration): 3-pin surface-mount package with exposed tab connected to IN for enhanced thermal dissipation (R_thJC = 15 °C/W). Compact footprint (4.4–4.6 mm × 2.29–2.60 mm) suits high-density industrial PCBs.

Pin/Terminal	Circuit Role	Design Meaning
1 (GND)	Common ground reference	Low-impedance return path for output current and internal bias; must be tied to solid ground plane.
2 (IN)	Input voltage supply	Accepts 2.5–18 V DC; connects to exposed tab for improved thermal conduction in SOT-89 D config.
3 (OUT)	Regulated 2.5 V output	Delivers up to 200 mA; requires ≥1 μF ceramic capacitor (1–22 μF) directly at pin for stability.

Key Features

Feature	Design Value
Ceramic capacitor compatibility	Stable with 1 μF C_OUT (ESR as low as 0.01 Ω) - eliminates cost, size, and reliability penalties of bulkier capacitors.
Logic-controlled shutdown	EN pin not present in SOT-89 version - this variant is fixed-output only with no enable function (per Table 3, SOT-89 D config).
High PSRR at low frequency	88 dB @ 120 Hz - rejects line-frequency ripple from AC/DC adapters or switching converter coupling.
Wide operating temperature	–40 °C to 125 °C junction range - qualified for industrial motor drives, factory automation, and outdoor equipment.
Integrated protections	Current limit (~330 mA), SOA foldback, and thermal shutdown - removes need for external fault-handling circuitry.

Applications

Digital Still Camera (DSC) Power Rail

Blu-ray Disc Player Audio Section

Use Scenario: Powers image signal processor (ISP) core voltage and ADC reference in compact DSC modules.

IC Role / Device Role / Timing Role: Primary 2.5 V LDO supplying noise-sensitive analog blocks; replaces discrete regulators requiring larger capacitors.

Use Value: 63 μV_RMS output noise and 88 dB PSRR preserve SNR in 14-bit image capture pipelines.

Use Scenario: Supplies DAC and headphone amplifier bias in BD player mainboard audio subsystem.

IC Role / Device Role / Timing Role: Low-noise post-regulator after DC-DC converter; provides clean 2.5 V for audio codec analog section.

Use Value: 100 mV dropout enables efficient use of 3.3 V intermediate rail, minimizing heat generation near audio components.

Industrial PLC I/O Module

PC Embedded Controller Supply

Use Scenario: Regulates 2.5 V for isolated CAN transceiver logic and ADC reference in DIN-rail mounted PLCs.

IC Role / Device Role / Timing Role: Local point-of-load regulator with thermal shutdown for field-side power domains.

Use Value: 125 °C max operating temperature and SOA protection ensure reliability in unventilated enclosures.

Use Scenario: Provides standby 2.5 V rail for embedded controller (EC) managing keyboard, touchpad, and thermal sensors.

IC Role / Device Role / Timing Role: Always-on LDO with ultra-low shutdown current (<1 μA) preserving system battery during sleep states.

Use Value: 60 μA quiescent current extends coin-cell life in legacy laptop EC designs beyond 5 years.

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, industrial-grade LDO applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLV70725DBVR	200 mA, 2.5 V fixed, 250 mV dropout @ 200 mA, 50 μA IQ, SOT-23-5 - lacks thermal shutdown and SOA protection.	Targeted at consumer portables; not rated for 125 °C operation or industrial transient environments.	Select only if thermal robustness is secondary and board space favors SOT-23-5 over SOT-89.
MCP1703T-2502E/MB	250 mA, 2.5 V fixed, 600 mV dropout @ 250 mA, 4 μA IQ, SOT-89 - higher dropout limits usable input range; no enable pin in SOT-89 variant.	Optimized for ultra-low-power battery backup; lower PSRR (70 dB @ 120 Hz) reduces noise rejection capability.	Prefer when minimum quiescent current dominates over PSRR and thermal safety requirements.

Compared with TLV70725DBVR and MCP1703T-2502E/MB, the LDK320M25R uniquely combines industrial temperature rating, integrated thermal/overcurrent protection, and high PSRR in a proven SOT-89 package - making it the preferred choice for mission-critical embedded power where reliability outweighs marginal IQ savings.

Availability

LDK320M25R is available at Aetrix Electronics and suitable for industrial PLCs, Blu-ray disc players, digital still cameras, and PC embedded controllers requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LDK320M25R 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 power management applications.

The LDK320 series belongs to ST's high-accuracy, high-PSRR LDO portfolio targeting industrial and consumer power management - engineered for low-noise analog supply, wide input range, and robust protection in harsh thermal environments.

FAQ

Is the LDK320M25R pin-compatible with other SOT-89 LDOs?

No - the LDK320M25R uses the SOT-89 D configuration (Pin 1 = GND, Pin 2 = IN, Pin 3 = OUT), which differs from standard SOT-89 (Pin 1 = OUT, Pin 2 = GND, Pin 3 = IN). This layout prioritizes thermal performance via IN-connected tab but requires dedicated PCB footprint alignment.

Does the LDK320M25R support an enable function?

No - the SOT-89 packaged LDK320M25R does not include an enable (EN) pin. Enable functionality is only available on SOT23-5L variants (e.g., LDK320AM25R). This simplifies control logic but removes software-controlled power gating capability.

What is the minimum recommended output capacitance?

The minimum recommended output capacitance is 1 μF ceramic (X5R/X7R), with ESR between 0.01 Ω and 1 Ω. Stability is maintained up to 22 μF; values below 1 μF risk oscillation per Figure 25 in DS11321 Rev 13.

Can the LDK320M25R be used with input voltages below 2.5 V?

No - the absolute minimum input voltage is 2.5 V per Table 4 (Absolute Maximum Ratings). Operation below this threshold violates specification and may cause unregulated output or undefined behavior; dropout voltage cannot be guaranteed below VIN = VOUT + V_DROP.

LDK320M25R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: SC-74A, SOT-753

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 18V

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: -

Current - Output:: 200mA

Current - Quiescent (Iq):: 90 µA

Current - Supply (Max):: 100 µA

PSRR:: 83dB ~ 58dB (120Hz ~ 10kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

LDK320M25R FAQ

1.How can I place an order for LDK320M25R through Aetrix?

Please submit a Request for Quotation (RFQ) for LDK320M25R on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LDK320M25R reliable?

The price and inventory of LDK320M25R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK320M25R is usually 5 days.

3.What payment methods are accepted for LDK320M25R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK320M25R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LDK320M25R?

LDK320M25R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LDK320M25R order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LDK320M25R?

For technical support, including LDK320M25R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK320M25R requirements.

6.How does Aetrix verify that LDK320M25R is sourced from the original manufacturer or authorized distributors?

All LDK320M25R products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LDK320M25R meets industry standards.

7.What is the process for return or replacement of LDK320M25R?

All LDK320M25R units undergo pre-shipment inspection (PSI). If there is an issue with LDK320M25R, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LDK320M25R part is unused and in its original packaging.

Return procedure for LDK320M25R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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