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

STMicroelectronics LDK120C32R

Name: LDK120C32R
Brand: STMicroelectronics
SKU: LDK120C32R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LDK120C32R

Manufacturer:: STMicroelectronics

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

Package:: 5-TSSOP, SC-70-5, SOT-353

Datasheet:: LDK120C32R.pdf

Description:: IC REG LIN 3.2V 200MA SOT323-5

Quantity:: RFQ Add To RFQ list

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Inventory:940

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Product details

Overview

LDK120C32R from STMicroelectronics is a 3.2 V fixed-output, 200 mA 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 noise-sensitive battery-powered systems such as digital still cameras and cordless phones.

For engineers reviewing the LDK120C32R datasheet, LDK120C32R pinout, LDK120C32R application, or LDK120C32R equivalent, this page delivers verified electrical specs, SOT323-5L package details, enable-controlled shutdown behavior, ceramic-capacitor compatibility (1 µF COUT), and real-world use context for portable low-power designs.

Technical Context

The LDK120C32R integrates a precision bandgap reference, error amplifier, and PMOS pass transistor to deliver stable 3.2 V output with minimal dropout and ultra-low noise. Its logic-controlled EN pin enables active-high operation with sub-1 µA shutdown current, and internal thermal/short-circuit protection ensures robustness under fault conditions.

Stabilized with only 1 µF ceramic output capacitor, it achieves 51 µVRMS output noise (10 Hz–100 kHz) when using a 10 nF bypass capacitor, and maintains 55 dB supply voltage rejection across 120 Hz–10 kHz - critical for powering analog sensors or RF front-ends in compact portable devices.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	Fixed 3.2 V ±2.0% at 25 °C - ensures stable biasing for 3.3 V-tolerant I/O without external feedback.
Max output current	200 mA guaranteed - sufficient to power multiple low-power microcontrollers or image sensor subsystems.
Dropout voltage	100 mV typ. at 100 mA load - enables operation down to 3.3 V input while maintaining regulation, extending battery runtime.
Quiescent current	≤100 µA max (≤1 µA in OFF mode) - minimizes standby drain in always-on portable applications.
Noise performance	51 µVRMS (with 10 nF BYP cap) - meets stringent requirements for ADC references or audio codec supplies.
Input voltage range	1.9 V to 5.5 V - compatible with single-cell Li-ion, Li-poly, or dual-cell alkaline/NiMH sources.
Operating temperature	−40 °C to +125 °C junction - supports industrial and automotive-adjacent portable equipment environments.

Pinout & Package

LDK120C32R is packaged in SOT323-5L - a 5-pin, surface-mount plastic package measuring 2.0 mm × 2.1 mm × 0.9 mm (max height), optimized for space-constrained portable PCBs and compatible with standard reflow profiles.

Pin/Terminal	Circuit Role	Design Meaning
1 (IN)	Input voltage supply	Accepts 1.9–5.5 V DC; requires local 1 µF ceramic decoupling (CI) close to pin.
2 (GND)	Power ground reference	Common return path for IN, OUT, EN, and BYP; must be low-impedance plane connection.
3 (EN)	Enable control input	Active-high logic: ≥1.2 V = ON, ≤0.4 V = shutdown (I_Q < 1 µA); pulled high via resistor if not driven.
4 (BYP/NC)	Bypass capacitor terminal (fixed version)	Optional 10 nF ceramic capacitor to GND reduces output noise; leave floating if unused - no board routing required.
5 (OUT)	Regulated 3.2 V output	Delivers up to 200 mA; stabilized by 1 µF ceramic capacitor (COUT); low ESR essential for stability.

Key Features

Feature	Design Value
Ultra-low noise regulation	51 µVRMS (10 Hz–100 kHz) with BYP cap - enables clean power for precision analog circuits without added filtering.
Ceramic capacitor compatibility	Stable with 1 µF COUT - eliminates need for costly tantalum or aluminum electrolytic capacitors, reducing BOM cost and footprint.
Logic-controlled shutdown	EN pin draws <100 nA; enables system-level power sequencing and deep-sleep modes in battery-operated firmware.
Internal protection	Thermal shutdown (160 °C) and constant-current short-circuit limiting (400 mA) - prevents damage during overloads or solder shorts.
Wide input range	1.9–5.5 V operation - supports direct connection to partially discharged Li-ion cells (≥3.2 V) while regulating 3.2 V output.

Applications

Digital Still Camera Power Rail

Cordless Phone Baseband Supply

Use Scenario: Powers CMOS image sensor and ISP core requiring low-noise, tightly regulated 3.2 V.

IC Role / Device Role / Timing Role: Primary LDO delivering clean bias to analog front-end and pixel array clock domains.

Use Value: 51 µVRMS noise and ±2.0% tolerance prevent image banding and color shift under varying battery voltage.

Use Scenario: Supplies baseband processor and RF transceiver IC in DECT cordless handsets.

IC Role / Device Role / Timing Role: Main 3.2 V rail enabling low-power sleep/wake cycles and fast EN-controlled power-up.

Use Value: Sub-1 µA shutdown current extends standby time beyond 30 days on single AAA battery.

Personal Digital Assistant (PDA) Memory Interface

Portable Medical Glucose Meter

Use Scenario: Provides regulated 3.2 V to NAND flash and SRAM in legacy PDA designs.

IC Role / Device Role / Timing Role: Point-of-load regulator ensuring stable I/O voltage during burst read/write operations.

Use Value: 100 mV dropout allows continued operation until battery drops to 3.3 V - maximizing usable capacity.

Use Scenario: Powers electrochemical sensor interface and low-power MCU in handheld glucose meters.

IC Role / Device Role / Timing Role: Safety-critical analog supply where noise and long-term voltage drift impact measurement accuracy.

Use Value: ±2.0% output tolerance at 25 °C and −40 °C to +125 °C range ensures consistent sensor excitation across operating environments.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6206P322MR	3.2 V fixed, 150 mA, 120 mV dropout @ 100 mA, 1 µA IQ, SOT23-3	Limited to 150 mA; no EN pin or BYP option - simpler but less flexible for dynamic power control.	Choose for cost-sensitive, low-current designs where enable/shutdown is handled externally.
Richtek RT9193-32GB	3.2 V fixed, 300 mA, 250 mV dropout @ 150 mA, 60 µA IQ, SOT23-5	Higher dropout and lower noise (75 µVRMS) - trades efficiency for higher current capability.	Choose when >200 mA peak load is expected and board space permits larger thermal solution.

Compared with XC6206P322MR and RT9193-32GB, LDK120C32R uniquely balances 200 mA drive, ultra-low noise (51 µVRMS), and sub-1 µA shutdown - making it optimal for noise-sensitive, battery-limited applications where both performance and longevity matter.

Availability

LDK120C32R is available at Aetrix Electronics and suitable for digital still cameras, cordless phone baseband systems, and portable medical glucose meters requiring stable component supply, full production traceability, and long-term lifecycle support.

Supply support for LDK120C32R 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 regulation in space- and power-constrained portable electronics.

FAQ

What is the minimum input voltage required for LDK120C32R to maintain 3.2 V output at 200 mA?

The dropout voltage is 300 mV max at 200 mA and 40–125 °C per datasheet Table 4. Therefore, minimum input is 3.2 V + 0.3 V = 3.5 V under worst-case thermal/load conditions. At room temperature and 100 mA, 3.3 V input suffices due to 100 mV typical dropout.

Can LDK120C32R operate with a 1 µF ceramic output capacitor without external compensation?

Yes - the device is internally compensated and stable with 1 µF ±20% X5R/X7R ceramic capacitors (ESR 5–30 mΩ). Figure 25 confirms stability across 1–22 µF COUT values, and no external components are needed for basic operation.

Is the BYP pin mandatory for noise reduction in LDK120C32R?

No - the BYP pin is optional. When used, a 10 nF ceramic capacitor to GND reduces output noise from 148 µVRMS to 51 µVRMS. If omitted, the pin must remain unconnected (floating) with no PCB trace - not tied to GND or OUT.

Does LDK120C32R support reverse-voltage or reverse-current protection?

No - the device lacks integrated reverse-voltage or reverse-current blocking. Input polarity must be maintained; back-driving the OUT pin above IN can cause leakage or damage. External protection (e.g., series Schottky diode) is required in bidirectional or hot-swap scenarios.

LDK120C32R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 5-TSSOP, SC-70-5, SOT-353

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 3.2V

Voltage - Output (Max):: -

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-323-5

LDK120C32R FAQ

1.How can I place an order for LDK120C32R through Aetrix?

Please submit a Request for Quotation (RFQ) for LDK120C32R 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 LDK120C32R reliable?

The price and inventory of LDK120C32R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK120C32R is usually 5 days.

3.What payment methods are accepted for LDK120C32R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK120C32R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LDK120C32R?

LDK120C32R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LDK120C32R 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 LDK120C32R?

For technical support, including LDK120C32R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK120C32R requirements.

6.How does Aetrix verify that LDK120C32R is sourced from the original manufacturer or authorized distributors?

All LDK120C32R 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 LDK120C32R meets industry standards.

7.What is the process for return or replacement of LDK120C32R?

All LDK120C32R units undergo pre-shipment inspection (PSI). If there is an issue with LDK120C32R, 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 LDK120C32R part is unused and in its original packaging.

Return procedure for LDK120C32R:

1.Submit a request within 90 days.

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

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