Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

STMicroelectronics LDK320M33R

Name: LDK320M33R
Brand: STMicroelectronics
SKU: LDK320M33R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: LDK320M33R

Manufacturer:: STMicroelectronics

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

Package:: SC-74A, SOT-753

Datasheet:: LDK320M33R.pdf

Description:: IC REG LINEAR 3.3V 200MA SOT23-5

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,705

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

LDK320M33R from STMicroelectronics is a 3.3 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. Used in DSC, TV, and industrial power rails where compact size and low quiescent current are critical.

For engineers reviewing the LDK320M33R datasheet, LDK320M33R pinout, LDK320M33R application, or LDK320M33R equivalent, this page delivers verified electrical specs, thermal performance data, SOT-89 terminal mapping, real-world load/line transient behavior, and validated alternatives for battery-powered and space-constrained embedded systems.

Technical Context

The LDK320M33R implements a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout and high PSRR without requiring external compensation. Its enable input (EN) controls internal bias generation, reducing total supply current to ≤1 μA in shutdown mode.

Thermal shutdown (160 °C, 20 °C hysteresis) and foldback current limiting protect against overload and ambient extremes. The device is optimized for ceramic capacitors (1–22 μF, ESR ≥ 0.01 Ω), with stability confirmed across full temperature and load range per Figure 25 of DS11321 Rev 13.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	Fixed 3.3 V ±2% over –40 °C to 125 °C - ensures stable MCU core or interface rail under thermal stress.
Max output current	200 mA - sufficient for powering microcontrollers, sensors, or small FPGAs without external boost.
Dropout voltage	100 mV typ. @ 100 mA - enables operation down to VIN = 3.4 V while maintaining regulation.
PSRR	88 dB @ 120 Hz - suppresses ripple from noisy DC-DC converters feeding the LDO input.
Quiescent current	60 μA typ. active / 0.2–1 μA off - extends battery life in always-on IoT nodes.
Input voltage range	2.5 V to 18 V - accommodates wide-input industrial supplies and automotive transients.
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 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) ideal for dense PCB layouts.

Pin/Terminal	Circuit Role	Design Meaning
1 (GND)	Common ground reference	Low-impedance return path for all internal circuitry; must be connected to main system GND plane.
2 (IN)	Regulator input voltage	Accepts 2.5–18 V; connects directly to tab for improved thermal conduction in high-power operation.
3 (OUT)	Regulated output voltage	Delivers stable 3.3 V; requires ≥1 μF ceramic capacitor placed within 2 mm of pin for stability.

Key Features

Feature	Design Value
Ceramic capacitor compatibility	Stable with 1–22 μF X7R/X5R ceramics - eliminates need for costly tantalum or electrolytic capacitors.
Logic-controlled shutdown	EN pin not present on SOT-89; device is always active - simplifies design where continuous operation is required.
High PSRR at low frequency	88 dB @ 120 Hz - rejects ripple from AC-DC adapters and switching pre-regulators without additional filtering.
Wide operating temperature	–40 °C to 125 °C junction - qualified for industrial control, automotive infotainment, and outdoor equipment.
Short-circuit protection	Foldback current limit (200–330 mA) - prevents thermal runaway during output fault conditions.

Applications

Digital Still Camera (DSC) Power Rail

TV Audio/Video Signal Chain

Use Scenario: Powers image sensor analog front-end and ISP core logic in compact DSC modules.

IC Role / Device Role / Timing Role: Primary 3.3 V LDO delivering clean, low-noise supply to noise-sensitive ADCs and PLLs.

Use Value: 63 μV_RMS output noise and 88 dB PSRR preserve SNR in 12-bit+ imaging pipelines.

Use Scenario: Supplies HDMI PHY, audio DAC, and tuner demodulator ICs in flat-panel TV mainboard.

IC Role / Device Role / Timing Role: Local point-of-load regulator decoupling switching DC-DC outputs.

Use Value: 100 mV dropout enables use with 5 V bus even after diode drop or cable loss.

Industrial PLC I/O Module

BD/DVD Player Microcontroller Core

Use Scenario: Provides isolated 3.3 V for ARM Cortex-M based controller and CAN transceiver in DIN-rail mount PLC.

IC Role / Device Role / Timing Role: Main system regulator handling variable 12–24 V field supply with transient immunity.

Use Value: 18 V max input and 125 °C operation support unregulated industrial bus designs.

Use Scenario: Powers DVD drive controller ASIC and flash memory interface in consumer optical disc players.

IC Role / Device Role / Timing Role: Secondary LDO downstream of buck converter, ensuring clean 3.3 V for timing-critical interfaces.

Use Value: 60 μA quiescent current reduces standby power in devices with frequent sleep/wake cycles.

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout voltage regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LDK320AM33R	±0.5% output accuracy vs. ±2% (LDK320M33R); same SOT-89 package and electrical specs.	Required where tighter voltage tolerance is needed for precision ADC references or low-voltage FPGA I/O banks.	Select when absolute output accuracy is prioritized over cost; identical pinout and layout.
LDK220M33R	150 mA max output, lower IQ (45 μA typ.), same 3.3 V fixed output and SOT-23-5L package.	Suitable for lower-current peripherals (e.g., UART transceivers, EEPROMs) where board space is more constrained than current demand.	Choose for area-sensitive designs needing smaller footprint; not drop-in due to different package and pin count.

Compared with LDK320M33R, LDK320AM33R improves voltage accuracy without trade-offs in size or thermal performance, while LDK220M33R sacrifices 50 mA output capability to reduce footprint and quiescent current-making it optimal only when current demand is ≤150 mA and space is premium.

Availability

LDK320M33R is available at Aetrix Electronics and suitable for digital still cameras, TV signal chains, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LDK320M33R 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 LDK320 series was developed specifically for space-constrained, battery-aware embedded systems requiring high PSRR, ultra-low dropout, and robust thermal protection in industrial-grade packages.

FAQ

Is LDK320M33R compatible with 1 μF ceramic output capacitors?

Yes. The LDK320M33R is fully stable with 1 μF X7R/X5R ceramic capacitors (minimum 1 μF, up to 22 μF), as confirmed in Figure 25 of DS11321 Rev 13. No ESR requirements or external compensation components are needed, simplifying BOM and layout.

What is the thermal resistance of the SOT-89 package?

The SOT-89 (D configuration) has R_thJA = 110 °C/W and R_thJC = 15 °C/W, per Table 5. With 200 mA output at 3.3 V and 12 V input, power dissipation is ~1.74 W; proper copper pour under the tab is essential to maintain T_J ≤ 125 °C.

Does LDK320M33R include an enable pin?

No. The SOT-89 variant (including LDK320M33R) does not feature an EN pin - it operates continuously when powered. Enable functionality is only available on SOT23-5L versions (e.g., LDK320AM33R in SOT23-5L).

How does LDK320M33R behave under short-circuit conditions?

It activates foldback current limiting: short-circuit current drops to 200 mA at VIN = 16 V (330 mA at lower VIN), combined with thermal shutdown at 160 °C and 20 °C hysteresis. This dual protection prevents latch-up and allows safe recovery after fault removal.

LDK320M33R 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):: 3.3V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.35V @ 200mA

Current - Output:: 200mA

Current - Quiescent (Iq):: 90 µA

Current - Supply (Max):: 100 µA

PSRR:: 88dB ~ 48dB (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

LDK320M33R FAQ

1.How can I place an order for LDK320M33R through Aetrix?

Please submit a Request for Quotation (RFQ) for LDK320M33R 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 LDK320M33R reliable?

The price and inventory of LDK320M33R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK320M33R is usually 5 days.

3.What payment methods are accepted for LDK320M33R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK320M33R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LDK320M33R?

LDK320M33R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LDK320M33R 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 LDK320M33R?

For technical support, including LDK320M33R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK320M33R requirements.

6.How does Aetrix verify that LDK320M33R is sourced from the original manufacturer or authorized distributors?

All LDK320M33R 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 LDK320M33R meets industry standards.

7.What is the process for return or replacement of LDK320M33R?

All LDK320M33R units undergo pre-shipment inspection (PSI). If there is an issue with LDK320M33R, 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 LDK320M33R part is unused and in its original packaging.

Return procedure for LDK320M33R:

1.Submit a request within 90 days.

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

Tech Hub

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…