STMicroelectronics ST1S30IPUR

Overview

ST1S30IPUR from STMicroelectronics is a 3 A, 1.5 MHz synchronous step-down DC-DC regulator with integrated NMOS/PMOS power switches, inhibit control, and over-voltage protection. It operates from 2.7 V to 5.5 V input, delivers regulated output down to 0.8 V, and achieves >90% typical efficiency at full load. Used in portable battery-powered systems requiring compact, high-efficiency power conversion.

For engineers reviewing the ST1S30IPUR datasheet, ST1S30IPUR pinout, ST1S30IPUR application, or ST1S30IPUR equivalent, key selection criteria include its 1.5 MHz fixed-frequency current-mode PWM architecture, DFN8 (4 × 4 mm) thermal performance (R_thJA = 40 °C/W), inhibit logic threshold (1.2–1.3 V), and integrated synchronous rectification eliminating external diodes.

Technical Context

The ST1S30IPUR employs current-mode PWM control with fixed 1.5 MHz switching frequency, enabling stable regulation under fast load transients and supporting ultra-small external LC components (e.g., 2.2 µH inductor, 10–22 µF ceramic capacitors). Its dual-supply architecture separates analog (VIN_A) and switch (VIN_SW) rails for noise isolation and efficiency optimization.

Thermal protection triggers at 150 °C with 20 °C hysteresis, while output over-voltage protection clamps at 105–110% of setpoint and limits current to 300 mA. The inhibit function disables switching when the INH pin voltage falls below 0.4 V, reducing quiescent current to 1 µA.

Key Specifications

Pinout & Package

ST1S30IPUR is housed in a thermally enhanced DFN8 (4 mm × 4 mm, 0.9 mm height) package with exposed thermal pad. The package supports PCB-level heat dissipation via direct GND plane connection to the exposed pad (R_thJC = 10 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62864DRLR and MP2451DT-LF-Z, ST1S30IPUR uniquely combines 3 A capability, dual supply rails, inhibit control, and integrated OVP in a DFN8 package - making it optimal for compact, battery-powered systems demanding robustness and analog integrity.

Availability

ST1S30IPUR is available at Aetrix Electronics and suitable for portable SSD power rails, industrial IoT sensor nodes, automotive body control modules, and medical wearable displays requiring stable component supply and long-term manufacturability.

Supply support for ST1S30IPUR 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 products for automotive, industrial, and consumer markets with emphasis on energy efficiency and reliability.

The ST1S30 belongs to ST's high-efficiency DC-DC converter product line, engineered specifically for space-constrained, battery-powered applications needing low quiescent current, thermal resilience, and integrated protection features.

FAQ

What is the minimum recommended output voltage for ST1S30IPUR?

The ST1S30IPUR supports output voltages as low as 0.8 V, determined by its 800 mV internal feedback reference and external resistor divider. For V_OUT ≤ 1.2 V, Figure 4 in the datasheet specifies a 1 µF feedforward capacitor (C3) across the upper feedback resistor to improve phase margin and transient response.

How does the inhibit function behave during startup and fault conditions?

When INH is pulled low (<0.4 V), the ST1S30IPUR halts switching, disables internal regulators, and draws only 1 µA. It does not assert any flag or status signal - the output simply collapses. During startup, INH must be held high (>1.2 V) before or concurrent with VIN application to ensure proper soft-start and avoid latch-up.

Can ST1S30IPUR operate with input voltage below 2.7 V?

No - the absolute minimum input voltage is 2.7 V per datasheet specifications. Below this, UVLO activates and disables regulation. The device will not start or sustain operation at 2.5 V or lower, even with light load, due to internal biasing and gate drive limitations of the integrated MOSFETs.

Is the exposed thermal pad electrically isolated or required to be grounded?

Per datasheet Table 2 and mechanical drawing, the exposed pad is internally connected to GND and must be soldered to a PCB ground plane. Leaving it floating degrades thermal performance (R_thJA increases from 40 to >70 °C/W) and risks instability due to parasitic inductance and EMI coupling.