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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

STMicroelectronics ST1S41PUR

Name: ST1S41PUR
Brand: STMicroelectronics
SKU: ST1S41PUR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST1S41PUR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 8-VDFN Exposed Pad

Datasheet:: ST1S41PUR.pdf

Description:: IC REG BUCK ADJ 4A 8DFN

Quantity:: RFQ Add To RFQ list

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Inventory:3,707

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Product details

Overview

ST1S41PUR from STMicroelectronics is a synchronous step-down switching regulator delivering up to 4 A output current, operating from 4.0 V to 18 V input, with adjustable output down to 0.8 V and fixed 850 kHz switching frequency. It integrates 95 mΩ high-side and 69 mΩ low-side MOSFETs, supports all-ceramic capacitor designs, and features cycle-by-cycle current limiting and internal soft-start - used in FPGA core supplies and point-of-load power for consumer TVs and optical storage.

For engineers reviewing the ST1S41PUR datasheet, ST1S41PUR pinout, ST1S41PUR application, or ST1S41PUR equivalent, key selection criteria include verified 4 A DC output capability, confirmed 0.8 V reference accuracy (±2%), validated VFQFPN 4×4-8L thermal resistance (40 °C/W), and functional compatibility with enable-controlled sequencing in multi-rail systems.

Technical Context

The ST1S41PUR implements peak current mode control with an integrated oscillator, slope compensation, and transconductance error amplifier featuring embedded RC/CC compensation (70 kΩ / 195 pF). Its control loop delivers 100 kHz bandwidth and 45° phase margin under typical 12 V_IN/1.2 V_OUT/4 A conditions.

It employs high-side current sensing and low-side diode emulation for accurate current limiting, with dual overcurrent thresholds (OCP1 ≈ 5–7 A, OCP2 ≈ OCP1 + 1 A) enabling frequency foldback and hard-shutdown during short-circuit events. Thermal shutdown activates at 150 °C with 20 °C hysteresis.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Current	4 A continuous - supports FPGA core rails and ASIC I/O supplies without external current boosting.
Input Voltage Range	4.0 V to 18 V - compatible with 5 V, 12 V, and 15 V intermediate bus architectures.
Output Voltage Range	0.8 V to V_IN - enables 0.8 V core regulation for modern µPs and configurable 1.2–3.3 V I/O via resistor divider.
Switching Frequency	850 kHz (typ.) - balances efficiency and size; allows compact 1.5 µH inductors and MLCC-based filtering.
Feedback Reference	0.8 V ±2% - ensures tight output regulation across temperature and load, critical for low-voltage logic rails.
Power MOSFET R_DS(on)	95 mΩ (HS), 69 mΩ (LS) - minimizes conduction loss at 4 A, enabling >90% efficiency at 12 V_IN/1.2 V_OUT.
Soft-Start Duration	1 ms - controls inrush current during startup, preventing input rail sag and output overshoot.

Pinout & Package

ST1S41PUR is housed in a thermally enhanced VFQFPN 4 mm × 4 mm, 8-lead package with exposed thermal pad (ePAD) connected to PGND. The package supports ≤40 °C/W junction-to-ambient thermal resistance on standard 2-layer PCBs with 1-in² copper pour.

Pin/Terminal	Circuit Role	Design Meaning
VINA	Unregulated auxiliary input	Supplies internal bias circuitry; decoupled with 330 nF–1 µF ceramic capacitor near pin.
EN	Enable control input	Active-high logic: ≥1.2 V enables regulation; ≤0.4 V disables with <4.5 µA standby current.
FB	Feedback sensing node	Compares output voltage to 0.8 V reference; requires external resistor divider for V_OUT > 0.8 V.
AGND	Analog ground reference	Reference for FB, EN, and internal error amplifier; must be star-connected to ePAD/PGND at single point.
VINSW	Main power input	High-current path for switch node operation; connects to bulk input capacitor and inductor input.
SW	Switch node output	Drives external inductor; carries high dv/dt square wave; layout requires minimal loop area.
PGND	Power ground return	Low-impedance return for high-side/low-side MOSFETs and inductor; tied directly to ePAD.
ePAD	Thermal & electrical ground	Exposed pad soldered to PCB ground plane; mandatory for thermal performance and EMI reduction.

Key Features

Feature	Design Value
Integrated Power Stage	95 mΩ HS + 69 mΩ LS MOSFETs eliminate external switches and reduce BOM count by 4+ components.
All-Ceramic Support	Stable operation with MLCC-only input/output capacitors - eliminates electrolytic aging and improves reliability.
Cycle-by-Cycle Current Limit	Real-time peak current monitoring prevents inductor saturation and MOSFET failure during transient overload.
Current Foldback Protection	Reduces current limit to ~2 A and switching frequency to 1/4 rate during sustained short-circuit - limits thermal stress.
Internal Compensation	Embedded 70 kΩ/195 pF network eliminates external compensation components and guarantees stability across full load range.

Applications

FPGA Core Supply

DVD/Blu-ray Player SoC Rail

Use Scenario: Providing tightly regulated 0.85–1.2 V supply to Xilinx Artix-7 or Intel Cyclone V FPGA cores under dynamic load steps up to 3 A/µs.

IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering stable core voltage with <±1% line/load regulation and sub-10 µs transient response.

Use Value: Enables reliable FPGA configuration and high-speed logic operation without brownout or timing violation due to voltage droop.

Use Scenario: Generating 1.8 V and 3.3 V I/O rails for DVD player main SoC (e.g., MediaTek MT8560) with burst-mode video decoding loads.

IC Role / Device Role / Timing Role: Point-of-load regulator supporting rapid load changes during MPEG-2 decode bursts while maintaining <20 mV ripple.

Use Value: Prevents SoC reset or frame drop by sustaining output voltage within spec during 2 A load transients at 100 kHz.

Set-Top Box Memory Interface

Hard Disk Drive Preamp Supply

Use Scenario: Powering DDR3/DDR4 memory termination and interface circuits in cable/satellite STBs with variable 1.5 V/1.35 V requirements.

IC Role / Device Role / Timing Role: Adjustable buck converter configured via resistor divider to match JEDEC-specified memory VDDQ tolerances.

Use Value: Ensures signal integrity and setup/hold timing compliance across temperature by holding VDDQ within ±3% over 0–4 A load range.

Use Scenario: Delivering clean 5 V analog supply to HDD preamplifier ICs requiring ultra-low noise (<50 µV_RMS) and high PSRR.

IC Role / Device Role / Timing Role: Secondary buck stage following primary 12 V rail; optimized for low EMI and minimal switching noise coupling.

Use Value: Reduces bit-error rate by suppressing switching artifacts that would otherwise corrupt read-channel analog signals.

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2315DJ-LF-Z	3 A rated, 500 kHz switching, 0.8 V ref, no internal soft-start timer - requires external RC network.	Limited to ≤3 A loads; lower switching frequency increases inductor size; lacks current foldback protection.	Select when cost sensitivity outweighs 4 A headroom and robust short-circuit handling.
TPS54332DR	3.5 A rated, 1 MHz switching, external compensation, 0.8 V ref, adjustable soft-start via capacitor.	Requires 3 external compensation components; higher FSW enables smaller magnetics but increases gate drive loss.	Prefer when design flexibility (e.g., custom loop tuning or different FSW) justifies added BOM complexity.

Compared with MP2315DJ-LF-Z and TPS54332DR, ST1S41PUR provides higher guaranteed output current (4 A vs. ≤3.5 A), integrated thermal/current protection with foldback, and factory-compensated stability - reducing design risk for high-reliability consumer and industrial PoL applications.

Availability

ST1S41PUR is available at Aetrix Electronics and suitable for FPGA core supplies, set-top box SoC rails, and optical storage device power management requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for ST1S41PUR 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, designing and manufacturing analog, power, microcontroller, and sensor solutions for automotive, industrial, and consumer markets.

The ST1S41PUR belongs to ST's high-efficiency monolithic DC-DC converter product line, engineered specifically for space-constrained, high-current point-of-load applications in consumer electronics and computing infrastructure.

FAQ

What is the maximum recommended output current for continuous operation?

The ST1S41PUR is rated for 4 A continuous DC output current under specified thermal conditions: ambient temperature ≤60 °C, 1-in² copper pour on 2-layer PCB, and proper ePAD soldering. At higher ambient or reduced copper area, derating applies per the 40 °C/W R_thJA value and 150 °C max junction temperature.

Can ST1S41PUR operate with only ceramic capacitors on input and output?

Yes - the ST1S41PUR is explicitly designed for all-ceramic capacitor operation. Its internal compensation and peak current mode control ensure stability with low-ESR MLCCs. Recommended input: ≥10 µF 25 V X7R; output: ≥22 µF 6.3 V X5R/X7R, placed close to SW and PGND pins.

How does the enable (EN) pin behave during power-up sequencing?

The EN pin has a 1.2 V turn-on threshold and 0.4 V turn-off threshold with 2 µA input current. When pulled high to V_IN or a clean 3.3 V rail, it initiates 1 ms internal soft-start. A 100 kΩ pulldown resistor is recommended if left unconnected to guarantee safe default-OFF behavior.

What happens during a sustained output short-circuit condition?

Under sustained short-circuit, ST1S41PUR first enters current foldback (limiting to ~2 A) and reduces switching frequency to 212.5 kHz (1/4 of nominal). If the fault persists and junction temperature reaches 150 °C, thermal shutdown activates; operation resumes automatically once die cools to ~130 °C.

ST1S41PUR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-VDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 4V

Voltage - Input (Max):: 18V

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

Voltage - Output (Max):: 18V

Current - Output:: 4A

Frequency - Switching:: 850kHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-DFN (4x4)

ST1S41PUR FAQ

1.How can I place an order for ST1S41PUR through Aetrix?

Please submit a Request for Quotation (RFQ) for ST1S41PUR 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 ST1S41PUR reliable?

The price and inventory of ST1S41PUR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST1S41PUR is usually 5 days.

3.What payment methods are accepted for ST1S41PUR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST1S41PUR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST1S41PUR?

ST1S41PUR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST1S41PUR 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 ST1S41PUR?

For technical support, including ST1S41PUR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST1S41PUR requirements.

6.How does Aetrix verify that ST1S41PUR is sourced from the original manufacturer or authorized distributors?

All ST1S41PUR 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 ST1S41PUR meets industry standards.

7.What is the process for return or replacement of ST1S41PUR?

All ST1S41PUR units undergo pre-shipment inspection (PSI). If there is an issue with ST1S41PUR, 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 ST1S41PUR part is unused and in its original packaging.

Return procedure for ST1S41PUR:

1.Submit a request within 90 days.

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

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