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

STMicroelectronics LD29080S33R

Name: LD29080S33R
Brand: STMicroelectronics
SKU: LD29080S33R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD29080S33R

Manufacturer:: STMicroelectronics

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

Package:: TO-261-4, TO-261AA

Datasheet:: LD29080S33R.pdf

Description:: IC REG LINEAR 3.3V 800MA SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:3,559

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Product details

Overview

LD29080S33R from STMicroelectronics is a fixed-output 3.3 V, 800 mA low-dropout linear regulator in SOT-223 package, featuring 0.4 V typical dropout at full load, ±1% output voltage accuracy over –40°C to +125°C, and logic-controlled electronic shutdown. It delivers stable post-regulation for microcontroller core supplies in battery-powered embedded systems.

For engineers reviewing the LD29080S33R datasheet, LD29080S33R pinout, LD29080S33R application, or LD29080S33R equivalent, key selection criteria include dropout voltage at 800 mA, ground current vs. load, thermal resistance (R_thJA = 110 °C/W), and shutdown control interface compatibility with 2 V logic-high threshold.

Technical Context

The LD29080S33R implements a PNP-based LDO architecture with internal current and thermal limiting, enabling robust operation without external protection components. Its reference voltage (1.23 V) feeds an error amplifier driving the pass transistor, supporting fixed 3.3 V output via internal resistor divider.

It includes an inhibit input (INHIBIT pin) requiring ≥2 V to enable regulation - not internally pulled up - and guarantees stable operation with minimum 2 mA load current to prevent leakage-induced output drift across temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	3.3 V ±1% (3.267–3.333 V) at –40°C to +125°C, ensuring reliable MCU I/O and core rail compliance
Max output current	800 mA guaranteed, supporting mid-power SoCs and FPGA I/O banks without derating at T_A ≤ 85°C
Dropout voltage	0.4 V typ. at 800 mA, enabling 3.7 V Li-ion battery operation down to 3.7 V input while maintaining regulation
Quiescent current	14–35 mA at 800 mA load, balancing efficiency and transient response in always-on subsystems
Supply rejection	52–67 dB at 120 Hz, suppressing ripple from upstream switching converters in hybrid power architectures
Output noise	132 µV_RMS (10 Hz–100 kHz), suitable for noise-sensitive analog peripherals and ADC references
Shutdown current	130–180 µA with INHIBIT = GND, enabling ultra-low-power sleep modes in portable devices

Pinout & Package

SOT-223 package: surface-mount, thermally enhanced 4-pin outline with exposed thermal pad (pin 2 = GND, shared for electrical and thermal conduction).

Pin/Terminal	Circuit Role	Design Meaning
1 (VI)	Input voltage	DC supply input (2.5–13 V); requires ≥300 nF ceramic bypass capacitor for stability
2 (GND)	Ground	Power and signal reference; connects to thermal pad for junction-to-ambient heat dissipation
3 (VO)	Regulated output	3.3 V fixed output; requires ≥10 µF low-ESR output capacitor for transient response and PSRR
1 (INHIBIT)	Enable control	Active-high logic input; must be tied ≥2 V to enable regulation; floating or <0.8 V disables output

Key Features

Feature	Design Value
Ultra-low dropout	0.4 V typ. at 800 mA enables single-cell Li-ion (3.0–4.2 V) direct powering of 3.3 V rails
Thermal & current protection	Internally limited; no external foldback or shutdown circuitry required for safe continuous operation
High accuracy output	±1% over full temperature range eliminates need for post-production trimming in industrial designs
Logic-compatible enable	INHIBIT pin accepts standard 2–13 V logic high, simplifying interface with GPIOs or PMIC sequencers
Low-noise regulation	132 µV_RMS noise supports precision analog circuits without additional filtering stages

Applications

Microcontroller Core Supply

USB Peripheral Power

Use Scenario: Providing clean 3.3 V to ARM Cortex-M4/M7 microcontrollers in battery-operated edge nodes.

IC Role / Device Role / Timing Role: Primary LDO for CPU core and memory interface rails, delivering fast load-transient response during burst processing.

Use Value: 0.4 V dropout allows >90% battery utilization from 3.7 V nominal Li-ion, extending runtime by ~12% vs. legacy 1 V-drop regulators.

Use Scenario: Powering USB 2.0 transceivers and PHYs in host controllers where EMI and noise affect signal integrity.

IC Role / Device Role / Timing Role: Low-noise post-regulator for VBUS-derived 3.3 V, rejecting switching ripple from DC/DC converters.

Use Value: 132 µV_RMS noise and 67 dB SVR suppress common-mode jitter on USB D+/D– lines, reducing packet error rate.

Industrial Sensor Node

Set-Top Box Standby Rail

Use Scenario: Supplying 3.3 V to MEMS accelerometers, temperature sensors, and BLE radios in factory-floor wireless nodes.

IC Role / Device Role / Timing Role: Always-on LDO with shutdown control, enabling wake-on-event functionality via INHIBIT pin.

Use Value: 180 µA shutdown current extends 10-year battery life in sealed sensor enclosures using primary lithium cells.

Use Scenario: Generating 3.3 V standby rail for remote control receivers and real-time clocks in consumer AV equipment.

IC Role / Device Role / Timing Role: Secondary LDO powered from main 5 V rail, activated only when AC mains is present.

Use Value: ±1% output tolerance ensures RTC accuracy and IR receiver sensitivity across wide ambient temperature swings (–20°C to +70°C).

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLV73333PDBVR	300 mA max output, 170 mV dropout at 300 mA, 50 µV_RMS noise, SOT-23-5 package	Limited to low-current peripherals; lacks thermal shutdown margin for sustained 800 mA loads	Select when board space is critical and load never exceeds 300 mA; avoid for MCU core rails
TPS7A2033PDQNR	300 mA max, 130 mV dropout at 300 mA, 7 µV_RMS noise, 1.5 µA quiescent current	Optimized for ultra-low-I_q IoT sensors; insufficient current capability and thermal rating for 800 mA use	Prefer for battery-gauge-critical wearables; not suitable for power-dense applications requiring 800 mA

Compared with TLV73333PDBVR and TPS7A2033PDQNR, the LD29080S33R uniquely supports 800 mA continuous output with integrated thermal protection and 0.4 V dropout - essential for compact, high-reliability industrial power rails where current demand and thermal margin outweigh ultra-low-noise or ultra-low-I_q requirements.

Availability

LD29080S33R is available at Aetrix Electronics and suitable for microcontroller core supplies, USB peripheral power, industrial sensor nodes, and set-top box standby rails requiring stable component supply across automotive-grade temperature ranges and long production lifecycles.

Supply support for LD29080S33R 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 smart driving, power management, and embedded processing.

The LD29080 series belongs to ST's high-accuracy, medium-current LDO portfolio, engineered for post-regulation in cost-sensitive industrial and consumer systems where dropout voltage, thermal robustness, and ±1% accuracy are design-critical.

FAQ

What is the minimum load current required for stable operation of LD29080S33R?

The LD29080S33R requires a minimum load current of 2 mA across its full operating temperature range (–40°C to +125°C) to prevent output voltage rise caused by internal leakage currents. This is specified in ST's datasheet Note 4 and applies regardless of input voltage or output load transients.

Can LD29080S33R be used with input voltages above 13 V?

No - the absolute maximum input voltage is 30 V, but the device automatically enters shutdown above 14 V per Table 3. Operation above 13 V is outside the guaranteed electrical characteristics range; sustained input >13 V risks unregulated behavior and violates recommended operating conditions.

Is the INHIBIT pin internally pulled up, and what happens if left floating?

The INHIBIT pin is not internally pulled up. If left floating, it may assume an indeterminate logic state, causing unpredictable enable/disable behavior. To ensure reliable ON mode, it must be actively driven to ≥2 V; for OFF mode, tie directly to GND.

What output capacitor value and type are required for stability?

ST specifies a minimum 10 µF low-ESR ceramic capacitor (X5R/X7R) at the VO pin for stability and transient response. The datasheet Figure 17 confirms stability across 4.7–47 µF; tantalum or aluminum electrolytics are not recommended due to higher ESR and aging effects.

LD29080S33R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 13V

Voltage - Output (Min/Fixed):: 3.3V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.7V @ 800mA

Current - Output:: 800mA

Current - Quiescent (Iq):: 180 µA

Current - Supply (Max):: 35 mA

PSRR:: 67dB (120Hz)

Control Features:: -

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223

LD29080S33R FAQ

1.How can I place an order for LD29080S33R through Aetrix?

Please submit a Request for Quotation (RFQ) for LD29080S33R 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 LD29080S33R reliable?

The price and inventory of LD29080S33R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD29080S33R is usually 5 days.

3.What payment methods are accepted for LD29080S33R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD29080S33R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD29080S33R?

LD29080S33R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD29080S33R 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 LD29080S33R?

For technical support, including LD29080S33R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD29080S33R requirements.

6.How does Aetrix verify that LD29080S33R is sourced from the original manufacturer or authorized distributors?

All LD29080S33R 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 LD29080S33R meets industry standards.

7.What is the process for return or replacement of LD29080S33R?

All LD29080S33R units undergo pre-shipment inspection (PSI). If there is an issue with LD29080S33R, 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 LD29080S33R part is unused and in its original packaging.

Return procedure for LD29080S33R:

1.Submit a request within 90 days.

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

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