STMicroelectronics ST2S08BPQR

Overview

ST2S08BPQR from STMicroelectronics is a dual synchronous step-down DC-DC converter IC optimized for powering low-voltage digital cores in optical disc drive (ODD) systems. It delivers up to 1.5 A per channel across 3 V–5.5 V input, features adjustable 0.8 V–4.68 V output (via resistor dividers), 1.5 MHz fixed-frequency current-mode PWM control, and integrated NMOS/PMOS power switches with 150 mΩ/200 mΩ typical R_DS(on).

For engineers reviewing the ST2S08BPQR datasheet, ST2S08BPQR pinout, ST2S08BPQR application, or ST2S08BPQR equivalent, this device supports compact, high-efficiency dual-rail power delivery in space-constrained embedded systems where thermal management, low quiescent current (1.5 mA max), and fast transient response are critical selection criteria.

Technical Context

The ST2S08BPQR implements two independent current-mode PWM controllers with internal compensation, enabling stable regulation using only ceramic capacitors and small inductors. Each channel uses a dedicated switching node (SW1/SW2), feedback pin (FB1/FB2), and ground path (GND1/GND2) to minimize cross-talk and improve load transient immunity.

It integrates cycle-by-cycle current limiting (2 A typ.), thermal shutdown at 150 °C with 15 °C hysteresis, soft-start with 800 µs delay, and an inhibit function (INH) that fully disables both regulators when pulled low. The HV pin configures internal reference trimming and must be left floating or grounded.

Key Specifications

Pinout & Package

ST2S08BPQR is housed in a thermally enhanced QFN12L (4 mm × 4 mm, 0.9 mm height) package with exposed thermal pad. Pin 12 (GND_A) and the exposed pad must be soldered to a common system ground plane with ≥4 thermal vias for optimal thermal resistance (R_thJA = 60 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS65270PWP and RTQ2132B-QT, the ST2S08BPQR offers balanced dual-channel capability, lowest component count (no external compensation), and optimal thermal performance in QFN12L - making it the preferred choice for non-automotive, space-constrained dual-rail embedded systems.

Availability

ST2S08BPQR is available at Aetrix Electronics and suitable for optical disc drives, FPGA power management, portable media players, and embedded DSP systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ST2S08BPQR 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, microcontrollers, and analog products.

The ST2S08B belongs to ST's high-efficiency DC-DC converter product line, engineered specifically for replacing linear regulators in digital core power applications where thermal density and board space are constrained.

FAQ

What is the maximum supported input voltage for ST2S08BPQR?

The absolute maximum input voltage on VIN_SW and VIN_A pins is 7 V, but the device is specified for continuous operation only between 3 V and 5.5 V. Exceeding 5.5 V may cause premature thermal shutdown or reduced reliability, and operation above 7 V risks permanent damage per Table 3 in the datasheet.

Can ST2S08BPQR regulate both outputs to different voltages simultaneously?

Yes - each channel has independent feedback pins (FB1 and FB2) and switching nodes (SW1 and SW2). By connecting separate resistor dividers to FB1 and FB2, users can set VO1 and VO2 to distinct values (e.g., 1.2 V and 3.3 V), provided both remain within 0.8 V to 85 % of VIN.

Is an external compensation network required for ST2S08BPQR?

No - the ST2S08BPQR integrates full Type II compensation internally. No external capacitors or resistors are needed for loop stability, simplifying design and reducing bill-of-materials. This is confirmed in Section 7 ("General information") and Figure 3 of the datasheet.

How does the INH pin behave during power-up sequences?

The INH pin is active-high with 1.2 V threshold (min) and 0.4 V turn-off level (max). When held low during power-up, it keeps both channels disabled until INH rises above 1.2 V, allowing precise sequencing control - e.g., enabling ST2S08BPQR only after main 5 V rail stabilizes.