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

STMicroelectronics LD39300DT12-R

Name: LD39300DT12-R
Brand: STMicroelectronics
SKU: LD39300DT12-R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD39300DT12-R

Manufacturer:: STMicroelectronics

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

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: LD39300DT12-R.pdf

Description:: IC REG LINEAR 1.22V 3A DPAK

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Inventory:410

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Product details

Overview

LD39300DT12-R from STMicroelectronics is a 1.22 V fixed-output, 3 A ultra-low-dropout linear voltage regulator in DPAK package, featuring 200 mV typical dropout at full load, 1.2 mA typical quiescent current in active mode, and logic-controlled shutdown with <1 µA off-state current. It operates from 2.5 V to 6 V input and is designed for microprocessor core power supply where tight regulation, fast transient response, and ceramic-capacitor stability are required.

For engineers reviewing the LD39300DT12-R datasheet, LD39300DT12-R pinout, LD39300DT12-R application, or LD39300DT12-R equivalent, key selection criteria include guaranteed 3 A output current, ±1.5% output voltage tolerance at 25°C, thermal and current limiting protection, inhibit pin control interface, and compatibility with low-ESR ceramic output capacitors ≥4.7 µF.

Technical Context

The LD39300DT12-R uses a BiCMOS process to decouple quiescent current from load current-enabling stable 1.2 mA IQ across 10 mA to 3 A output range. Its error amplifier drives an N-channel pass transistor with internal current and thermal foldback, supporting fast load-step recovery (e.g., 10 mA → 3 A in <20 µs) without external compensation.

It integrates a precision 1.22 V bandgap reference and supports stable operation with ceramic output capacitors as low as 4.7 µF (ESR ≤ 20 mΩ), eliminating need for tantalum or aluminum electrolytics. The inhibit pin (VINH) provides TTL/CMOS-compatible enable control with defined thresholds: ON when ≥2 V, OFF when ≤0.3 V-no internal pull-up/down.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.22 V ±1.5% at 25°C; enables direct core supply for 1.2 V–1.25 V logic domains.
Max Output Current	3 A guaranteed; supports high-current SoC/DSP core rails without derating at T_J ≤ 125°C.
Dropout Voltage	200 mV typ. @ 3 A; allows operation with VI = 1.42 V min, critical for battery-backed or post-regulation systems.
Quiescent Current	1.2 mA typ. @ 3 A load; maintains efficiency under heavy load unlike CMOS LDOs with rising IQ.
Shutdown Current	1 µA max @ 25°C; reduces system standby power in always-on subsystems.
Line Regulation	0.04% typ.; limits output drift to ±0.49 mV over VI = VO+1 V to 6 V, ensuring stable core voltage during input ripple.
Load Regulation	0.06%/A; holds output within ±18 mV across full 10 mA–3 A load range.

Pinout & Package

DPAK (TO-252) package: thermally enhanced surface-mount outline with exposed drain pad for PCB heat sinking; JEDEC MS-012AC compliant; RoHS-compliant ECOPACK® with lead-free terminations.

Pin/Terminal	Circuit Role	Design Meaning
VINH	Inhibit control input	Active-high enable: ≥2 V = ON, ≤0.3 V = OFF; must be externally driven-no internal bias.
VI	Input voltage supply	Accepts 2.5–6 V; requires 1 µF ceramic capacitor placed ≤1 cm from pin with dedicated ground return.
VO	Regulated output	Delivers 1.22 V ±1.5%; requires ≥4.7 µF ceramic output capacitor with ESR ≤20 mΩ for stability.
GND	Power and signal ground	Common reference for VI, VO, VINH; must be low-impedance plane shared only with input/output caps.

Key Features

Feature	Design Value
Ultra-low dropout	200 mV @ 3 A enables use in 1.5 V input systems-critical for Li-ion single-cell or post-buck applications.
BiCMOS architecture	Decouples IQ from I_LOAD, maintaining 1.2 mA quiescent current even at full 3 A output-unlike PMOS LDOs with exponential IQ rise.
Ceramic capacitor stability	Stable with ≥4.7 µF X7R/X5R ceramics (ESR ≤20 mΩ); eliminates cost, size, and reliability penalties of tantalum alternatives.
Fast transient response	Load step recovery time <20 µs (10 mA ↔ 3 A); prevents core voltage droop during CPU burst activity.
Integrated protection	Thermal shutdown at 170°C with 10°C hysteresis and current limit at 6 A prevent damage during overload or short-circuit events.

Applications

Microprocessor Core Supply

DSP Power Rail

Use Scenario: Providing clean, tightly regulated 1.22 V to ARM Cortex-A series or RISC-V SoC cores operating at up to 2 GHz.

IC Role / Device Role / Timing Role: Primary core voltage regulator with fast load transient response to handle dynamic DVFS voltage scaling.

Use Value: Maintains <±18 mV output deviation during 10 mA ↔ 3 A load steps, preventing timing violations or cache corruption.

Use Scenario: Powering TI C6000 or Analog Devices SHARC DSPs requiring low-noise, low-dropout 1.22 V supply for analog front-end and digital logic.

IC Role / Device Role / Timing Role: Low-noise linear post-regulator following a switching DC/DC converter to suppress switching noise.

Use Value: 100 µV_RMS output noise (10 Hz–100 kHz) preserves SNR in ADC/DAC signal chains.

Post-Regulator for Switching Supplies

Industrial FPGA I/O Bank Supply

Use Scenario: Final-stage regulation after a 3.3 V buck converter to deliver precise 1.22 V to memory interfaces (LPDDR4, GDDR6).

IC Role / Device Role / Timing Role: Noise-filtering LDO that rejects 55 dB of 1 kHz ripple from upstream switcher.

Use Value: 65 dB PSRR at 120 Hz ensures <10 µV ripple on output-critical for jitter-sensitive SerDes links.

Use Scenario: Supplying configurable I/O banks on Xilinx Artix-7 or Intel Cyclone V FPGAs requiring stable 1.22 V with programmable enable control.

IC Role / Device Role / Timing Role: Programmable power rail managed via FPGA GPIO-driven VINH pin for power sequencing.

Use Value: <1 µA shutdown current enables selective bank power-down without affecting other FPGA domains.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6210B122MR-G	1.22 V fixed, 300 mA max output, SOT-25 package, 150 mV dropout @ 300 mA	Not suitable for 3 A loads; limited to low-power MCU peripherals or sensors	Select only for space-constrained, sub-500 mA applications where DPAK thermal mass is unnecessary
ON Semiconductor NCP1117DT12RKG	1.2 V fixed, 1 A max, TO-252 package, 1.2 V dropout @ 1 A, higher IQ (6 mA)	Lacks inhibit pin, lower current rating, and slower transient response	Use only if system does not require shutdown control or >1 A current; verify thermal margin at full load

Compared with XC6210B122MR-G and NCP1117DT12RKG, LD39300DT12-R uniquely delivers 3 A output with 200 mV dropout and logic-controlled shutdown in the same DPAK footprint-enabling direct replacement in high-current, power-managed designs without board rework.

Availability

LD39300DT12-R is available at Aetrix Electronics and suitable for microprocessor core supplies, DSP power rails, and FPGA I/O bank regulation requiring stable component supply across automotive infotainment, industrial PLCs, and edge AI accelerators.

Supply support for LD39300DT12-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 LD39300 belongs to ST's high-performance LDO portfolio targeting low-voltage, high-current applications in portable and embedded systems-specifically engineered for core power delivery where dropout, noise, and transient response are critical.

FAQ

What is the minimum input voltage required for LD39300DT12-R to maintain regulation at 3 A?

The minimum input voltage is calculated as VO + VDROP = 1.22 V + 0.2 V = 1.42 V. However, the absolute minimum specified VI is 2.5 V per datasheet Section 4 (Maximum Ratings) and Section 5 (Electrical Characteristics), which defines operational conditions. Thus, 2.5 V is the guaranteed functional lower limit-not 1.42 V-due to internal bias and protection circuitry requirements.

Can LD39300DT12-R operate without an input capacitor?

No. The datasheet mandates a minimum 1 µF ceramic input capacitor located ≤1 cm from the VI pin with a dedicated low-impedance ground return. Omitting it risks instability, excessive input ripple coupling, and potential damage during line transients-verified in Section 7.2 and Figure 18 (line transient test setup).

Is the LD39300DT12-R pin-compatible with other ST LDOs in DPAK?

No. Pin configuration differs across ST's DPAK LDO families: LD39300 uses VINH/VI/VO/GND (4-pin), while LD1117 uses IN/GND/OUT (3-pin), and LD3985 uses IN/EN/OUT/GND (4-pin but different assignment). Direct substitution requires schematic and layout revision per Figure 2 (Pin connections) and Table 1 (Pin description).

Does LD39300DT12-R require a heatsink in standard PCB layouts?

Not necessarily. With R_thJA = 100°C/W (DPAK), dissipation at 3 A with 200 mV dropout is 0.6 W, yielding ~60°C junction rise above ambient. For T_A ≤ 65°C, T_J stays below 125°C. Adequate copper pour (≥250 mm² on top/bottom layers) typically suffices-per thermal data in Table 3 and Section 7.4.

LD39300DT12-R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Cut Tape (CT)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 6V

Voltage - Output (Min/Fixed):: 1.22V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.4V @ 3A

Current - Output:: 3A

Current - Quiescent (Iq):: 5 µA

Current - Supply (Max):: 2.5 mA

PSRR:: 65dB ~ 55dB (120Hz ~ 1kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

LD39300DT12-R FAQ

1.How can I place an order for LD39300DT12-R through Aetrix?

Please submit a Request for Quotation (RFQ) for LD39300DT12-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 LD39300DT12-R reliable?

The price and inventory of LD39300DT12-R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD39300DT12-R is usually 5 days.

3.What payment methods are accepted for LD39300DT12-R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD39300DT12-R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD39300DT12-R?

LD39300DT12-R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD39300DT12-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 LD39300DT12-R?

For technical support, including LD39300DT12-R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD39300DT12-R requirements.

6.How does Aetrix verify that LD39300DT12-R is sourced from the original manufacturer or authorized distributors?

All LD39300DT12-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 LD39300DT12-R meets industry standards.

7.What is the process for return or replacement of LD39300DT12-R?

All LD39300DT12-R units undergo pre-shipment inspection (PSI). If there is an issue with LD39300DT12-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 LD39300DT12-R part is unused and in its original packaging.

Return procedure for LD39300DT12-R:

1.Submit a request within 90 days.

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

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