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

STMicroelectronics ST1S32PUR

Name: ST1S32PUR
Brand: STMicroelectronics
SKU: ST1S32PUR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST1S32PUR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 8-VDFN Exposed Pad

Datasheet:: ST1S32PUR.pdf

Description:: IC REG BUCK ADJ 4A 8DFN

Quantity:: RFQ Add To RFQ list

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Inventory:8,944

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Product details

Overview

ST1S32PUR from STMicroelectronics is a 4 A synchronous step-down DC-DC regulator with 2.8–5.5 V input, adjustable 0.8 V output, 1.5 MHz fixed-frequency PWM control, integrated 60 mΩ high-side and 45 mΩ low-side MOSFETs, and Power Good (PG) monitoring - used in FPGA core supplies and point-of-load regulation for consumer electronics.

For engineers reviewing the ST1S32PUR datasheet, ST1S32PUR pinout, ST1S32PUR application, or ST1S32PUR equivalent, key selection criteria include peak current mode stability, ceramic-capacitor compatibility, cycle-by-cycle overcurrent protection, and VFDFPN 8 4×4×1.0 mm thermal performance at 4 A continuous load.

Technical Context

The ST1S32PUR implements peak current mode control with internal slope compensation to prevent subharmonic oscillation above 50% duty cycle. Its transconductance error amplifier (gm = 238 μA/V, DC gain = 94 dB) features fully embedded RC/CC compensation (R_C = 80 kΩ, C_C = 55 pF), delivering 117 kHz bandwidth and 63° phase margin under typical 5 V_IN/1.2 V_OUT/4 A conditions.

It integrates UVLO (2.0 V turn-off, 2.4 V turn-on), hysteretic thermal shutdown (150 °C trip, 130 °C recovery), and dual-stage overcurrent protection: cycle-by-cycle limiting at 5.0 A followed by current foldback (2.3 A limit) with frequency reduction when FB falls below 0.2 V - enabling robust short-circuit survival without external circuitry.

Key Specifications

Parameter	Value and Actual Design Meaning
Output current	4 A continuous - supports high-current FPGA I/O rails and ASIC core domains without external current boosting.
Input voltage range	2.8 V to 5.5 V - compatible with single-cell Li-ion, 3.3 V/5 V system rails, and intermediate bus architectures.
Switching frequency	1.5 MHz (typ.) - enables compact 1.0 µH inductors and small ceramic output capacitors (e.g., 47 µF MLCC).
Feedback reference	0.8 V ±1% - sets precise output regulation; external resistor divider allows scalable V_OUT from 0.8 V to V_IN.
Power Good threshold	92% of V_FB (≈0.736 V at 0.8 V ref) with 170 µs delay - provides reliable power sequencing for µP reset assertion.
On-resistance (HS/LS)	60 mΩ / 45 mΩ - minimizes conduction loss at 4 A, enabling >90% efficiency at 1.2 V_OUT/3 A with proper layout.
Soft-start duration	400 µs - controls inrush current during startup, preventing input rail sag and downstream supply brownouts.

Pinout & Package

ST1S32PUR is housed in a thermally enhanced VFDFPN 8 4×4×1.0 mm package with exposed thermal pad (PGND-connected) for PCB-level heat dissipation. The 0.5 mm pitch leads support fine-pitch routing and high-density layouts.

Pin/Terminal	Circuit Role	Design Meaning
VINA	Unregulated input bypass	Accepts local 330 nF–1 µF ceramic decoupling; minimizes noise coupling into analog feedback path.
EN	Enable control	Logic-compatible input (ON ≥1.5 V, OFF ≤0.5 V); internal pull-down ensures safe default-off state.
FB	Feedback sensing	High-impedance node referenced to 0.8 V internal bandgap; connects to resistor divider for output voltage programming.
AGND	Analog ground	Separate ground return for FB, EN, and PG to avoid switching noise injection into control loop.
PG	Open-drain Power Good	Signals valid regulation after 170 µs delay; requires external pull-up for µP reset or sequencing logic.
VINSW	Main power input	High-current VIN path feeding HS FET; must be routed with low-inductance, wide copper pour adjacent to SW.
SW	Switch node	Connects to inductor and boot capacitor; high dv/dt node requiring tight layout and minimal parasitic capacitance.
PGND	Power ground	Low-impedance return for HS/LS FETs and inductor; tied to thermal pad for optimal junction-to-PCB thermal resistance (40 °C/W).

Key Features

Feature	Design Value
All-ceramic capacitor support	Eliminates electrolytic/tantalum requirements - reduces board area, improves reliability, and avoids ESR-related instability.
Integrated power MOSFETs	60 mΩ HS + 45 mΩ LS switches enable self-contained 4 A buck conversion without external drivers or discrete FETs.
Current foldback protection	Automatically reduces switching frequency and limits peak current to 2.3 A during overload - sustains regulated operation without latch-off.
Internal soft-start	400 µs ramp prevents inrush-induced voltage droop on shared input rails and avoids false PG assertion.
Thermal shutdown with hysteresis	150 °C trip / 130 °C recovery prevents thermal runaway while allowing automatic recovery after transient overload cooling.

Applications

FPGA Core Supply

DVD/STB Point-of-Load

Use Scenario: Delivering stable 1.2 V @ 3–4 A to Xilinx Spartan or Intel Cyclone FPGA core logic under dynamic load transients.

IC Role / Device Role / Timing Role: Primary synchronous buck regulator providing tightly regulated core voltage with fast transient response and PG signaling for configuration sequencing.

Use Value: Internal compensation and 1.5 MHz switching enable <100 ns load-step response with <50 mV undershoot using only 1 µH inductor and 47 µF MLCC.

Use Scenario: Generating 3.3 V @ 2.5 A for digital video processing ICs in set-top boxes and DVD players with strict standby current limits.

IC Role / Device Role / Timing Role: High-efficiency PoL converter with EN-controlled sleep mode and ultra-low 10 µA standby IQ for energy-compliant designs.

Use Value: Integrated MOSFETs and light-load frequency reduction maintain >85% efficiency at 10 mA load, meeting EU ErP Tier 2 standby requirements.

Hard Disk Drive Actuator

Audio/Graphics Card I/O Rail

Use Scenario: Supplying 2.5 V @ 3.5 A to HDD voice coil motor drivers and preamplifier circuits with high ripple rejection.

IC Role / Device Role / Timing Role: Low-noise buck regulator with ceramic-input filtering and separate AGND/PGND planes to suppress switching noise in analog-sensitive signal chains.

Use Value: 0.8 V reference accuracy (±1%) and cycle-by-cycle current limiting ensure consistent actuator positioning torque across temperature and aging.

Use Scenario: Providing 1.8 V @ 4 A to GPU memory interfaces (GDDR5/GDDR6) in desktop graphics cards with high thermal density.

IC Role / Device Role / Timing Role: Thermally optimized buck stage mounted directly beneath VRM heatsink, leveraging VFDFPN thermal pad for junction-to-PCB conduction.

Use Value: 40 °C/W R_thJA and 4 A capability allow full-load operation at 75 °C ambient without derating - validated on ST demonstration board.

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
TPS54332DR	3 A rated, 0.8 V ref, 1.0 MHz switching, external MOSFETs required	Lacks integrated power FETs and PG output; requires additional components for 4 A operation	Select only if lower cost per watt justifies added BOM count and layout complexity.
MP2315DJ-LF-Z	4 A rated, 0.8 V ref, 1.5 MHz, integrated FETs, but no PG output or current foldback	Missing Power Good signaling and foldback protection - unsuitable for safety-critical sequencing or short-circuit-prone environments	Prefer for cost-sensitive, non-sequenced loads where thermal shutdown alone suffices.

Compared with TPS54332DR and MP2315DJ-LF-Z, ST1S32PUR uniquely combines 4 A integration, PG signaling, and current foldback in a 4×4 mm VFDFPN package - making it optimal for space-constrained, high-reliability PoL systems requiring autonomous fault management.

Availability

ST1S32PUR is available at Aetrix Electronics and suitable for FPGA core supplies, optical storage power rails, and audio/graphic card I/O regulation requiring stable component supply across industrial temperature ranges and multi-year production cycles.

Supply support for ST1S32PUR 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, specializing in power management, microcontrollers, and analog ICs for automotive, industrial, and consumer markets.

The ST1S32PUR belongs to ST's ST1Sxx family of high-current synchronous buck regulators designed specifically for point-of-load applications demanding compact size, high efficiency, and robust protection in consumer and computing electronics.

FAQ

What is the minimum recommended output capacitor for ST1S32PUR at 1.2 V output?

The datasheet specifies 47 µF multilayer ceramic capacitor (MLCC) as the standard output capacitance for 1.2 V operation. This value ensures ≤1% output voltage ripple at 4 A load and maintains loop stability with the internal compensation network. Lower values may cause instability or excessive ripple; higher values improve transient response but increase cost and board area without proportional benefit.

Does ST1S32PUR require an external bootstrap capacitor?

No. ST1S32PUR uses a P-channel high-side MOSFET, eliminating the need for an external bootstrap capacitor or charge pump circuit. This simplifies layout, reduces component count, and improves reliability compared to N-channel-based synchronous buck controllers that mandate bootstrap networks.

How does the Power Good (PG) pin behave during startup and fault conditions?

The PG pin remains low until V_OUT reaches 92% of its target (e.g., 1.104 V for 1.2 V output), then releases after a 170 µs delay. If V_OUT drops below this threshold due to overload or input dropout, PG immediately pulls low. During thermal shutdown or OCP2 latch-off, PG also asserts low - providing unambiguous system-level fault indication without external monitoring.

Can ST1S32PUR operate with input voltage below 2.8 V?

No. Absolute maximum ratings specify -0.3 V to 7 V input, but functional operation is guaranteed only from 2.8 V to 5.5 V. Below 2.8 V, UVLO disables the regulator (VEN remains above 0.5 V but internal bias fails), and output regulation cannot be maintained. For sub-2.8 V inputs, consider ST1S12 or other dedicated low-VIN buck converters.

ST1S32PUR 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):: 2.8V

Voltage - Input (Max):: 5.5V

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

Voltage - Output (Max):: 5.5V

Current - Output:: 4A

Frequency - Switching:: 1.5MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

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

ST1S32PUR FAQ

1.How can I place an order for ST1S32PUR through Aetrix?

Please submit a Request for Quotation (RFQ) for ST1S32PUR 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 ST1S32PUR reliable?

The price and inventory of ST1S32PUR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST1S32PUR is usually 5 days.

3.What payment methods are accepted for ST1S32PUR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST1S32PUR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST1S32PUR?

ST1S32PUR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST1S32PUR 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 ST1S32PUR?

For technical support, including ST1S32PUR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST1S32PUR requirements.

6.How does Aetrix verify that ST1S32PUR is sourced from the original manufacturer or authorized distributors?

All ST1S32PUR 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 ST1S32PUR meets industry standards.

7.What is the process for return or replacement of ST1S32PUR?

All ST1S32PUR units undergo pre-shipment inspection (PSI). If there is an issue with ST1S32PUR, 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 ST1S32PUR part is unused and in its original packaging.

Return procedure for ST1S32PUR:

1.Submit a request within 90 days.

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

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