ST1S03PUR - 1.5A 1.5MHz Step-Down DC-DC Converter | STMicro
Teilenummer: ST1S03PUR ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $1.85 | $1,85 |
| 10 | $1.66 | $16,60 |
| 100 | $1.3 | $130,00 |
| 500 | $1.08 | $540,00 |
| 1.000 | $0.92 | $920,00 |
| 3.000 | $0.78 | $2.340,00 |
ST1S03PUR Übersicht
A step-down switching regulator (buck converter) is a DC-DC converter that produces a lower DC output voltage from a higher DC input voltage by rapidly switching an internal MOSFET and storing energy in an inductor. Within the broader power management hierarchy, the ST1S03PUR sits in the DC-DC converter family (buck topology), which belongs to the voltage regulator category and ultimately the power management IC class used in virtually every battery- and bus-powered electronic system.
Key features of the ST1S03PUR include a 1.5 MHz switching frequency that enables sub-2 mm inductor solutions, internal soft-start that limits inrush current and provides a 50 to 100 microsecond power-on delay, 2 percent DC output voltage tolerance, current-mode PWM control for cycle-by-cycle current limiting, and not-switching quiescent current optimization that preserves battery life. The exposed thermal pad on the DFN-6 (3x3) package keeps junction temperature in check at full 1.5 A load.
The architecture combines a P-channel power MOSFET, a precision reference, an error amplifier, and a current-sense comparator inside a single die. The current-mode loop simplifies compensation with a single resistor-capacitor network and provides inherent line rejection, making the device robust against input voltage transients on 12 V buses. The 1.5 MHz switching frequency is well above the AM band, simplifying EMI filter design in audio and consumer products.
Typical applications include HDD digital core supplies, point-of-load conversion in 12 V distributed systems, USB-powered devices, and portable battery-powered equipment where the small DFN-6 footprint and high switching frequency enable compact PCB layouts. According to the STMicroelectronics ST1S03 datasheet, the device is optimized to replace high-current linear regulators when power dissipation would otherwise cause excessive heating.
When designing with the ST1S03PUR, choose an inductor with low DCR to minimize conduction loss, and place the input ceramic bypass capacitor as close as possible to the VIN and GND pins. Ensure that the feedback resistor divider sets VOUT between 0.8 V and approximately VIN times 0.85, and verify that the maximum rated junction temperature is not exceeded under worst-case VIN and IOUT conditions.
This page synthesizes distributor pricing, drop-in alternative cross-references, and practical design notes not found in the manufacturer datasheet alone.
Drop-in-Alternativen für ST1S03PUR – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Varianten dieser Serie
Modelle derselben Serie, die drop-in-kompatibel sind mit ST1S03PUR (gleiche Bauform und Footprint) – abweichend in Input Voltage Range, Output Voltage Range, Package, Switching Frequency, Topology.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
ST1S03PUR
✅ Drop-In✓ Auf Lager
$0.78 / Stück
Datenblatt ansehen →ST1S06PUR
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
ST1S03APUR
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
ST1S03PMR
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
RT8077GQW
✅ Drop-In✓ Auf Lager
$0.36 / Stück
Datenblatt ansehen →PI3VST01UE
✅ Drop-In✓ Auf Lager
$0.62 / Stück
Datenblatt ansehen →ST1S03PUR Grenzwerte & elektrische Eigenschaften
| Topologie | Step-down (buck) DC-DC converter |
| Control Scheme | Current-mode PWM |
| Schaltfrequenz | 1.5 MHz (typical) |
| Eingangsspannungsbereich | 3 V to 16 V |
| Ausgangsspannungsbereich | 0.8 V to VIN (adjustable) |
| Maximaler Ausgangsstrom | 1.5 A |
| DC Output Voltage Tolerance | 2 % |
| Internal Soft-Start | 50 us to 100 us power-on delay |
| Typical Efficiency | > 70 % |
| Betriebstemperaturbereich | -40 C to +125 C |
| Gehäuse | DFN-6 (3x3 mm) with exposed pad |
| Montageart | Surface Mount |
| RoHS-Status | Compliant |
ST1S03PUR Pin-Konfiguration
| Pin 1 | VIN — Input supply voltage (3 V to 16 V) |
| Pin 2 | GND — Ground reference |
| Pin 3 | FB — Feedback input for output voltage regulation (0.8 V reference) |
| Pin 4 | EN — Enable input (active high) |
| Pin 5 | SW — Switch node connection to external inductor |
| Pin 6 | PGND — Power ground (some revisions); tie to GND |
Typische Anwendungen
ST1S03PUR ist geeignet für 7 Anwendungs: HDD Digital Core Power Supply, Point-of-Load Conversion from 12 V Bus, USB-Powered Portable Device Rails, Replacement for High-Current Linear Regulators, FPGA Core and I/O Voltage Rails, IoT Sensor Node Power, Automotive Accessory and Aftermarket Modules.
HDD Digital Core Power Supply
The ST1S03PUR was originally designed by STMicroelectronics to power HDD digital cores at 1.8 V or 2.5 V from a 5 V or 12 V rail. Its 1.5 MHz fixed switching frequency enables a tiny 1.5 microhenry chip inductor, while the DFN-6 (3x3 mm) footprint fits inside the drive electronics enclosure. With 1.5 A capability and > 70 percent typical efficiency, it replaces high-current linear regulators that would otherwise create a thermal hotspot inside the sealed HDD housing. Soft-start limits inrush at power-on, protecting the motor spin-up sequence.
Empfohlen
Point-of-Load Conversion from 12 V Bus
In 12 V distributed power systems, the ST1S03PUR drops a 12 V bus rail to a 3.3 V or 5 V local load with 1.5 A capability. The high 1.5 MHz switching frequency pushes harmonics above the AM band, simplifying EMI filter design for industrial and networking equipment. Compared to a 12 V-to-3.3 V LDO that would dissipate over 13 W at full load, the ST1S03PUR maintains > 70 percent efficiency and keeps the DFN-6 footprint small enough for dense POL arrays on the motherboard.
Empfohlen
USB-Powered Portable Device Rails
USB ports supply 5 V at 500 mA standard or 1.5 A with battery charging downstream, making the ST1S03PUR an excellent point-of-load converter for USB-powered portable devices that need 3.3 V, 2.5 V, or 1.8 V cores. The 3 V minimum input handles 1-cell Li-ion battery droop, while the integrated P-channel MOSFET eliminates external switches to save BOM cost. Internal soft-start prevents large inrush currents from tripping USB current limiters during hot-plug events.
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Replacement for High-Current Linear Regulators
STMicroelectronics explicitly targets the ST1S03PUR at replacing high-current linear regulators when dissipation causes excessive heating. For example, dropping 5 V to 3.3 V at 1 A in an LDO wastes 1.7 W; the ST1S03PUR cuts that dissipation by 60 to 70 percent while keeping the solution footprint smaller than an LDO-plus-heatsink arrangement. This makes it ideal for sealed enclosures, fanless industrial boxes, and any thermal-constrained board where a TO-220 LDO is not an option.
Empfohlen
FPGA Core and I/O Voltage Rails
Many small-to-medium FPGAs require separate core (1.0 V to 1.8 V) and I/O (2.5 V to 3.3 V) rails at up to 1.5 A; the ST1S03PUR covers both rails with a single BOM per rail. The 1.5 MHz switching frequency keeps ripple well above the FPGA's sensitive PLL bandwidth, while the DFN-6 (3x3 mm) package fits beside BGA devices on dense boards. Soft-start avoids large inrush currents that could collapse the upstream 5 V or 12 V bus during configuration power-up.
Empfohlen
IoT Sensor Node Power
Battery-powered IoT sensor nodes often run from a 3.7 V Li-ion cell or a 5 V solar-harvested rail and need a regulated 3.3 V or 1.8 V supply for the MCU and radio. The ST1S03PUR's 3 V minimum input extends usable battery life into the discharge curve, while its not-switching quiescent current optimization preserves standby runtime. The DFN-6 (3x3) package keeps the converter footprint smaller than the antenna trace area, leaving room for sensors and battery management on the same PCB.
Empfohlen
Automotive Accessory and Aftermarket Modules
Aftermarket automotive accessories commonly run from a 12 V or 13.8 V vehicle bus and need 5 V, 3.3 V, or 1.8 V rails at modest current. The ST1S03PUR's 16 V maximum input tolerates load-dump transients up to its absolute maximum, while the DFN-6 exposed pad provides the thermal mass for sustained 1.5 A operation in a sealed module. Internal soft-start prevents inrush on the accessory sense wire when the ignition is switched on.
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Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für ST1S03PUR – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | ST1S03PUR | ST1S06PUR | ST1S03APUR | ST1S03PMR | RT8077GQW |
|---|---|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Richtek |
| Package | DFN-6 (3x3 mm) | DFN-6 (3x3) - same | DFN-6 (3x3) - same | DFN-6 (3x3) - same | VFQFPN-6 - same family | WDFN-6 (2x2) |
| Output Current | 1.5 A | 1.5 A | 3 A | 1.5 A | 1.5 A | 2 A |
| Input Voltage Range | 3 V to 16 V | 3 V to 16 V | 3 V to 16 V | 3 V to 5.5 V | 3 V to 16 V | 2.7 V to 6 V |
| Switching Frequency | 1.5 MHz | 1.5 MHz | 1.5 MHz | 1.5 MHz | 1.5 MHz | 1.5 MHz |
| Lifecycle Status | Active | Active | Active | Obsolete | Active | Active |
Wichtigste Unterscheidungsmerkmale
- Wide 3 V to 16 V input range in a tiny DFN-6 (3x3) package (vs. ST1S03APUR)
- 1.5 A output at 1.5 MHz fixed switching frequency (vs. RT8077GQW)
- Pin-compatible higher-current upgrade path within the same ST family (vs. ST1S06PUR)
Designhinweise
Estimated: at VIN = 12 V, VOUT = 3.3 V, and IOUT = 1.5 A, conduction loss in the integrated P-channel MOSFET and synchronous rectifier yields approximately 0.6 W internal dissipation. The DFN-6 (3x3) package has a typical theta_JA near 50 C/W on a 1 square inch copper pour, so junction temperature rises about 30 C above ambient. Always solder the exposed pad to a continuous copper pour of at least 1 square inch to keep Tj below 125 C under worst-case VIN and ambient conditions.
Place the input ceramic bypass capacitor (10 microfarad X5R or better) within 2 mm of the VIN and PGND pins to minimize switching-node ringing. Route the SW node trace away from FB and feedback resistors to avoid noise injection; use a Kelvin-sense connection for the upper feedback resistor tied to the output capacitor's positive terminal. The exposed thermal pad must be soldered to a top-layer copper pour that connects to PGND through multiple vias for heat extraction.
Do not exceed the 16 V absolute maximum input rating; load-dump transients on automotive 12 V buses can exceed this if unclamped. Do not operate without the inductor in place; the SW node must always see a path to GND through the inductor or the internal MOSFET will be damaged. Do not exceed 100 percent duty cycle by selecting VOUT above VIN; the device requires headroom to regulate and will pass VIN through to VOUT at dropout, defeating the buck topology.
Compliance-Informationen
RoHS compliant per STMicroelectronics product page; not AEC-Q100 qualified for automotive OEM safety-critical applications.
