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

STMicroelectronics LDK120M-R

Name: LDK120M-R
Brand: STMicroelectronics
SKU: LDK120M-R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LDK120M-R

Manufacturer:: STMicroelectronics

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

Package:: SC-74A, SOT-753

Datasheet:: LDK120M-R.pdf

Description:: IC REG LIN POS ADJ 200MA SOT23-5

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Product details

Overview

LDK120M-R from STMicroelectronics is an adjustable 200 mA low-dropout linear regulator with 100 mV typical dropout at 100 mA, 1 µA shutdown current, and 115 µV_RMS output noise (10 Hz–100 kHz) in SOT23-5L package. It operates from 1.9 V to 5.5 V input, supports 0.8 V to (V_IN − V_drop) output via external resistor divider, and features logic-controlled enable and internal thermal/current protection - used in battery-powered digital camera power rails.

For engineers reviewing the LDK120M-R datasheet, LDK120M-R pinout, LDK120M-R application, or LDK120M-R equivalent, key selection criteria include its ultra-low quiescent current (≤60 µA over temperature), ceramic-capacitor compatibility (C_OUT = 1 µF), ±3.0% output voltage accuracy across −40 °C to 125 °C, and validated stability with 1–22 µF output capacitance.

Technical Context

The LDK120M-R implements a PMOS pass transistor architecture enabling near-zero dropout behavior and eliminating reverse-current flow without external diodes. Its bandgap reference and error amplifier deliver tight load/line regulation (0.006 %/mA and 0.05 %/V), while the ADJ pin accepts 784–816 mV feedback voltage for precise output setting.

Thermal shutdown activates at 160 °C with 20 °C hysteresis; short-circuit current limiting holds output at ~400 mA during fault. The enable input (VEN) has guaranteed logic thresholds (V_IL ≤ 0.4 V, V_IH ≥ 1.2 V) across full temperature and input voltage range, ensuring robust control in noisy portable environments.

Key Specifications

Parameter	Value and Actual Design Meaning
Output current	200 mA guaranteed - sufficient to power image sensor bias, ISP core, or baseband IC in compact cameras.
Dropout voltage	100 mV typ. at 100 mA - enables operation down to 1.9 V input while delivering 1.8 V output, extending battery runtime.
Quiescent current	60 µA max at 25 °C, ≤100 µA over −40 °C to 125 °C - minimizes standby drain in always-on camera modules.
Output noise	115 µV_RMS (10 Hz–100 kHz) - low enough to avoid analog signal corruption in CCD/CMOS sensor analog chains.
Supply rejection	55 dB (120 Hz–10 kHz) - suppresses ripple from switching DC-DC stages feeding the LDO input.
Accuracy	±3.0% over −40 °C to 125 °C - ensures stable ADC reference or PLL supply under thermal stress.
Enable threshold	V_IL ≤ 0.4 V, V_IH ≥ 1.2 V - compatible with 1.8 V GPIOs without level-shifting in modern SoC designs.

Pinout & Package

LDK120M-R is supplied in SOT23-5L package (2.95 mm × 1.60 mm × 1.45 mm), optimized for space-constrained portable PCBs. Pin 1 is IN, Pin 2 is GND, Pin 3 is EN, Pin 4 is ADJ, Pin 5 is OUT - no NC pins; all five terminals are electrically active.

Pin/Terminal	Circuit Role	Design Meaning
1 (IN)	Input voltage supply	Accepts 1.9–5.5 V; must be decoupled with ≥1 µF ceramic capacitor close to pin.
2 (GND)	Power ground reference	Low-impedance return path for both input and output currents; connects to main system ground plane.
3 (EN)	Logic enable control	Active-high; pulls below 0.4 V to enter <1 µA shutdown mode; driven directly by 1.8 V microcontroller GPIO.
4 (ADJ)	Feedback voltage input	Receives 784–816 mV from resistor divider; sets V_OUT = V_ADJ × (1 + R1/R2); requires <1 µA bias current.
5 (OUT)	Regulated output	Delivers up to 200 mA; requires ≥1 µF ceramic output capacitor with ESR <10 Ω for stability.

Key Features

Feature	Design Value
Adjustable output range	0.8 V to (V_IN − V_drop) - enables single BOM for multiple voltage rails (e.g., 1.2 V core, 1.8 V I/O, 2.8 V sensor).
Ceramic capacitor support	C_OUT = 1 µF minimum - eliminates need for costly tantalum or aluminum electrolytic capacitors, reducing board area and cost.
Ultra-low shutdown current	<1 µA - preserves battery charge during camera sleep mode for weeks without recharge.
Integrated protection	Thermal shutdown (160 °C) + constant-current short-circuit limit (~400 mA) - prevents damage during solder reflow or field faults.
Wide operating temperature	−40 °C to 125 °C junction - qualified for automotive cabin-mounted dashcams and industrial inspection cameras.

Applications

Digital Still Camera Power Rail

Portable Medical Imaging Sensor

Use Scenario: Powers CMOS image sensor analog front-end and timing generator in compact DSLR-style cameras.

IC Role / Device Role / Timing Role: Provides ultra-low-noise 2.8 V bias for pixel readout circuitry and 1.2 V for digital logic, rejecting switcher ripple.

Use Value: 115 µV_RMS noise avoids fixed-pattern noise in raw image data; 100 mV dropout extends usable battery voltage range by >15 minutes per charge.

Use Scenario: Supplies regulated voltage to handheld ultrasound probe transducer driver and ADC in point-of-care devices.

IC Role / Device Role / Timing Role: Delivers stable 3.3 V for high-speed ADC sampling clock domain and 1.8 V for FPGA configuration memory.

Use Value: ±3.0% accuracy over temperature ensures consistent gain calibration; 55 dB SVR prevents switching noise from corrupting 16-bit medical data.

Wearable Fitness Tracker Core Supply

Industrial IoT Edge Node MCU Rail

Use Scenario: Powers ARM Cortex-M4F MCU and BLE radio in wrist-worn health monitors with coin-cell battery.

IC Role / Device Role / Timing Role: Generates 1.2 V core and 1.8 V I/O from single 3.0 V Li-ion cell; enabled only during sensor acquisition bursts.

Use Value: 1 µA shutdown current extends shelf life beyond 12 months; 60 µA quiescent current enables >7-day continuous heart-rate monitoring.

Use Scenario: Regulates power for RS-485 transceiver, microcontroller, and environmental sensor interface in factory-floor gateways.

IC Role / Device Role / Timing Role: Supplies 3.3 V to isolated communication ICs and 2.5 V to precision temperature/humidity sensors.

Use Value: −40 °C to 125 °C rating ensures reliability inside sealed enclosures near motors; thermal shutdown prevents latch-up during ambient spikes.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6219B122MR-G	Fixed 1.2 V output only; 150 mA max; 250 mV dropout at 100 mA; 40 µV_RMS noise.	Lacks adjustability; unsuitable where multiple voltages required from one BOM.	Select only if fixed 1.2 V suffices and lower noise is critical; verify thermal derating at 125 °C.
Analog Devices ADM7172ACPZ-R7	500 mA output; 125 mV dropout; 7 µV_RMS noise; requires 4.7 µF ceramic output cap.	Higher cost and larger 8-lead LFCSP package; over-specified for 200 mA use cases.	Choose when >300 mA peak load or sub-10 µV noise is mandatory; not cost-optimized for portable consumer.

Compared with XC6219B122MR-G, LDK120M-R offers design flexibility through adjustability and higher current; versus ADM7172ACPZ-R7, it delivers better cost-per-mA and smaller footprint at modest noise trade-off - ideal for volume portable imaging systems.

Availability

LDK120M-R is available at Aetrix Electronics and suitable for digital still cameras, portable medical imaging sensors, wearable fitness trackers, and industrial IoT edge nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LDK120M-R 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 targets ultra-low-power, noise-sensitive battery-operated applications - emphasizing minimal quiescent current, ceramic-capacitor compatibility, and robust thermal protection in miniature packages.

FAQ

What output capacitor value and type are required for stable operation?

LDK120M-R requires a minimum 1 µF ceramic capacitor (X5R/X7R, ≤10 Ω ESR) on the output. Stability is maintained up to 22 µF; tantalum or electrolytic capacitors are not recommended due to ESR and aging effects that may cause oscillation or poor transient response.

Can the ADJ pin be left floating if not used?

No - the ADJ pin must be connected to the output via a resistor divider to set V_OUT. Leaving it floating causes undefined regulation and potential device malfunction. For fixed-output variants (e.g., LDK120M25R), the ADJ pin is internally connected and unused externally.

How does thermal shutdown behave during sustained overload?

When junction temperature reaches 160 °C, LDK120M-R disables the pass transistor and enters thermal shutdown. It remains off until temperature drops by ~20 °C hysteresis, then automatically resumes regulation - preventing permanent damage during intermittent overloads like camera flash LED bursts.

Is the enable pin compatible with 1.2 V logic systems?

No - the enable pin requires V_IH ≥ 1.2 V to activate, but this is the *minimum guaranteed threshold*, not a nominal drive level. Driving EN from a true 1.2 V rail risks marginal activation; a 1.8 V or higher GPIO is recommended for reliable operation across voltage and temperature extremes.

LDK120M-R 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:: Adjustable

Number of Regulators:: 1

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 0.8V

Voltage - Output (Max):: 5.2V

Voltage Dropout (Max):: 0.3V @ 200mA

Current - Output:: 200mA

Current - Quiescent (Iq):: 60 µA

Current - Supply (Max):: 100 µA

PSRR:: 55dB (120Hz ~ 10kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

LDK120M-R FAQ

1.How can I place an order for LDK120M-R through Aetrix?

Please submit a Request for Quotation (RFQ) for LDK120M-R 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 LDK120M-R reliable?

The price and inventory of LDK120M-R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK120M-R is usually 5 days.

3.What payment methods are accepted for LDK120M-R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK120M-R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LDK120M-R?

LDK120M-R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LDK120M-R 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 LDK120M-R?

For technical support, including LDK120M-R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK120M-R requirements.

6.How does Aetrix verify that LDK120M-R is sourced from the original manufacturer or authorized distributors?

All LDK120M-R 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 LDK120M-R meets industry standards.

7.What is the process for return or replacement of LDK120M-R?

All LDK120M-R units undergo pre-shipment inspection (PSI). If there is an issue with LDK120M-R, 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 LDK120M-R part is unused and in its original packaging.

Return procedure for LDK120M-R:

1.Submit a request within 90 days.

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

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