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

STMicroelectronics LD39020ADTPU21R

Name: LD39020ADTPU21R
Brand: STMicroelectronics
SKU: LD39020ADTPU21R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD39020ADTPU21R

Manufacturer:: STMicroelectronics

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

Package:: 4-XDFN Exposed Pad

Datasheet:: LD39020ADTPU21R.pdf

Description:: IC REG LINEAR 2.1V 200MA 4DFN

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Inventory:9,955

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Product details

Overview

LD39020ADTPU21R from STMicroelectronics is a 2.1 V, ±0.5 % accuracy, 200 mA ultra-low-dropout linear regulator in DFN4 1×1 package, featuring 200 mV typical dropout at full load, 20 µA quiescent current at no load, and logic-controlled enable with 0.03 µA shutdown current-designed for precision power rails in battery-powered imaging and mobile baseband subsystems.

For engineers reviewing the LD39020ADTPU21R datasheet, LD39020ADTPU21R pinout, LD39020ADTPU21R application, or LD39020ADTPU21R equivalent, key selection criteria include output voltage tolerance (±0.5 %), thermal shutdown threshold (160 °C), soft-start timing (100 µs), PSRR (80 dB @ 1 kHz), and compatibility with 0.47 µF ceramic output capacitors.

Technical Context

The LD39020ADTPU21R integrates a bandgap reference, error amplifier, and PMOS pass transistor to deliver stable 2.1 V output across -40 °C to 125 °C junction temperature. Its internal soft-start circuit limits inrush current without external components, and the optional output discharge MOSFET (enabled in ADT variants) actively pulls VOUT to GND during shutdown.

It operates with input voltages from 1.5 V to 5.5 V and maintains regulation down to 2.3 V input (2.1 V + 200 mV dropout). The device uses a fixed internal feedback network for 2.1 V output and supports logic-level enable control with VIH = 1 V and VIL = 0.4 V over full temperature range.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	2.1 V ±0.5 % at 25 °C - ensures tight rail accuracy for low-voltage DSP cores and image sensor analog supplies
Max Output Current	200 mA guaranteed - sufficient for powering RF transceivers or multi-core microcontrollers in portable devices
Dropout Voltage	200 mV typ. @ 200 mA - enables operation from single-cell Li-ion (3.0 V min) or dual-cell alkaline (2.4 V min) sources
Quiescent Current	20 µA typ. @ no load - extends battery life in always-on standby modes of mobile and IoT endpoints
PSRR	80 dB @ 1 kHz - suppresses switching noise from adjacent DC-DC converters feeding noisy system rails
Enable Shutdown Current	0.03 µA typ. - reduces system leakage to sub-nA levels when host MCU disables peripheral power domains
Thermal Shutdown	160 °C with 20 °C hysteresis - provides robust protection during sustained high-load or poor PCB thermal design

Pinout & Package

LD39020ADTPU21R is housed in a 1 mm × 1 mm, 0.4 mm height DFN4 1x1 package with exposed thermal pad (connected to GND). This ultra-compact footprint supports high-density PCB layouts in space-constrained mobile and wearable applications.

Pin	Circuit Role	Design Meaning
1 (OUT)	Regulated output terminal	Delivers 2.1 V to load; requires ≥0.47 µF ceramic capacitor directly adjacent for stability
2 (GND)	Analog and power ground reference	Common return path for internal bias, error amp, and thermal pad; must be low-impedance connection to PCB ground plane
3 (EN)	Active-high enable input	Logic high ≥1 V enables regulation; logic low ≤0.4 V disables output and activates discharge MOSFET (if present)
4 (IN)	Input voltage supply	Accepts 1.5–5.5 V; requires ≥1 µF ceramic decoupling capacitor placed within 2 mm of pin
Thermal Pad	Internal die thermal conduction path	Must be soldered to solid GND copper area on PCB to achieve R_thJA = 250 °C/W and sustain full 200 mA load

Key Features

Feature	Design Value
Ultra-low dropout	200 mV @ 200 mA enables use with weak or deeply discharged batteries while maintaining regulation
Low-noise operation	45 µV_RMS (10 Hz–100 kHz) minimizes ripple-induced jitter in camera sensor clocking and ADC reference paths
Integrated soft-start	100 µs controlled ramp prevents inrush current spikes that could destabilize shared input rails
Output discharge function	On-chip NMOS (R_ON = 100 Ω) actively discharges output capacitor upon disable, eliminating hold-up voltage in fast-power-cycle systems
Ceramic capacitor compatible	Stable with 0.47–22 µF X5R/X7R ceramics - eliminates need for costly tantalum or electrolytic capacitors

Applications

Mobile Phone Baseband Power

Digital Still Camera Sensor Bias

Use Scenario: Powering 2.1 V I/O and core rails of application processors in LTE smartphones during active call and data sessions.

IC Role / Device Role: Primary LDO for noise-sensitive digital baseband subsystems requiring clean, tightly regulated voltage under dynamic load transients.

Use Value: 80 dB PSRR at 1 kHz rejects coupling from RF power amplifiers and switching regulators, preserving signal integrity in modem interfaces.

Use Scenario: Supplying analog front-end and column driver circuits in 12–20 MP CMOS image sensors during burst capture mode.

IC Role / Device Role: Low-noise, fast-transient LDO delivering stable 2.1 V bias to pixel readout and ADC reference circuits.

Use Value: 45 µV_RMS output noise prevents fixed-pattern noise and quantization errors in high-dynamic-range imaging pipelines.

Tablet Application Processor Core

Wireless Headset Audio Codec

Use Scenario: Providing 2.1 V core voltage to ARM Cortex-A series SoCs in compact tablets operating from single-cell Li-ion batteries.

IC Role / Device Role: High-accuracy, low-quiescent-current LDO supporting deep-sleep states and rapid wake-up sequences.

Use Value: 0.03 µA shutdown current and 20 µA no-load IQ extend battery runtime by >15 % in always-connected standby scenarios.

Use Scenario: Powering stereo audio DAC/ADC and Class-D amplifier stages in Bluetooth-enabled wireless headsets.

IC Role / Device Role: Compact, thermally efficient LDO supplying clean 2.1 V to low-voltage audio signal chains.

Use Value: DFN4 1×1 package (1 mm²) and integrated thermal pad allow placement directly beneath audio ICs for minimal trace inductance and optimal EMI performance.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6210B212MR-G	2.1 V ±2 % accuracy, 150 mA max, SOT-25 package, no output discharge	Lacks auto-discharge and thermal hysteresis; lower accuracy limits use in precision analog rails	Select when cost sensitivity outweighs need for 0.5 % tolerance and active discharge in wearables
Richtek RT9013-21GB	2.1 V ±2 %, 300 mA, SOT-23-5, 60 µA IQ, no soft-start or discharge	Higher quiescent current and missing soft-start increase inrush risk in multi-rail systems	Prefer for higher-current loads where 200 mV dropout and sub-µA shutdown are non-critical

Compared with XC6210B212MR-G and RT9013-21GB, LD39020ADTPU21R delivers superior accuracy (±0.5 % vs. ±2 %), lower shutdown current (0.03 µA vs. ≥1 µA), and integrated soft-start/discharge-making it optimal for battery-constrained, noise-sensitive, and fast-cycling applications where rail integrity and power sequencing matter.

Availability

LD39020ADTPU21R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, cordless phones, and portable media players requiring stable component supply, long-term lifecycle support, and automotive-grade reliability screening.

Supply support for LD39020ADTPU21R 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.

LD39020ADTPU21R belongs to ST's high-accuracy, ultra-low-IQ LDO family targeting battery-powered portable electronics-engineered to maximize runtime, minimize thermal footprint, and ensure signal integrity in multi-rail, space-constrained designs.

FAQ

What is the minimum input voltage required for LD39020ADTPU21R to maintain 2.1 V output at 200 mA?

The minimum input voltage is 2.3 V, calculated as V_OUT + V_DROP = 2.1 V + 200 mV (typical dropout at full load). At -40 °C to 125 °C, worst-case dropout is 350 mV, so 2.45 V input is recommended for guaranteed regulation across temperature.

Does LD39020ADTPU21R require an external soft-start capacitor?

No. The device integrates a factory-trimmed soft-start circuit with a fixed 100 µs startup time, eliminating the need for external timing components. This simplifies layout and improves reliability compared to discrete RC-based solutions.

Can LD39020ADTPU21R be used with a 0.22 µF output capacitor?

No. While the regulator remains stable down to 220 nF under ideal conditions, ST specifies a minimum of 0.47 µF ceramic capacitor (X5R/X7R) to ensure stability across temperature, input voltage, and load variations per Figure 17 in DS9956.

Is the thermal pad on the DFN4 1x1 package electrically connected internally?

Yes. The exposed thermal pad is internally connected to GND and must be soldered to a dedicated PCB ground plane with ≥4 thermal vias (0.3 mm diameter) to achieve rated R_thJA = 250 °C/W and sustain continuous 200 mA operation at 125 °C ambient.

LD39020ADTPU21R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 4-XDFN Exposed Pad

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):: 2.1V

Voltage - Output (Max):: -

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

Current - Output:: 200mA

Current - Quiescent (Iq):: 40 µA

Current - Supply (Max):: -

PSRR:: 80dB ~ 55dB (1kHz ~ 100kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature, Soft Start

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 4-DFN (1x1)

LD39020ADTPU21R FAQ

1.How can I place an order for LD39020ADTPU21R through Aetrix?

Please submit a Request for Quotation (RFQ) for LD39020ADTPU21R 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 LD39020ADTPU21R reliable?

The price and inventory of LD39020ADTPU21R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD39020ADTPU21R is usually 5 days.

3.What payment methods are accepted for LD39020ADTPU21R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD39020ADTPU21R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD39020ADTPU21R?

LD39020ADTPU21R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD39020ADTPU21R 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 LD39020ADTPU21R?

For technical support, including LD39020ADTPU21R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD39020ADTPU21R requirements.

6.How does Aetrix verify that LD39020ADTPU21R is sourced from the original manufacturer or authorized distributors?

All LD39020ADTPU21R 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 LD39020ADTPU21R meets industry standards.

7.What is the process for return or replacement of LD39020ADTPU21R?

All LD39020ADTPU21R units undergo pre-shipment inspection (PSI). If there is an issue with LD39020ADTPU21R, 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 LD39020ADTPU21R part is unused and in its original packaging.

Return procedure for LD39020ADTPU21R:

1.Submit a request within 90 days.

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

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