STMicroelectronics ST2S06D33PQR

Overview

ST2S06D33 from STMicroelectronics is a dual synchronous step-down DC-DC converter with reset function, delivering up to 0.5 A per channel, operating at 1.5 MHz fixed-frequency current-mode PWM, featuring 3.3 V fixed output on Channel 1 and 1.2 V adjustable output on Channel 2, and housed in QFN12L (4×4 mm) package for ODD digital core power supply.

For engineers reviewing the ST2S06D33 datasheet, ST2S06D33 pinout, ST2S06D33 application, or ST2S06D33 equivalent, key selection considerations include dual-channel reset timing (52–78 ms delay), input voltage range (4–5.5 V), ±2% output voltage tolerance, thermal shutdown at 130–150 °C, and synchronous rectification with R_DS(on) of 150 mΩ (NMOS) and 200 mΩ (PMOS).

Technical Context

The ST2S06D33 implements a constant-frequency current-mode PWM control architecture with internal soft-start ramp generation to limit inrush current and enforce 50–100 µs power-on delay. Its dual-output topology uses separate feedback loops: FB1 tied to fixed 3.3 V output (3.23–3.37 V), FB2 referenced to 1.2 V (784–816 mV), enabling independent regulation and load transient response within ±5% VO.

Reset functionality is triggered by VIN_A rising above 4.55 V (typ.) with hysteresis; delay time varies from 52 ms (min) to 78 ms (max) over temperature. Protection includes cycle-by-cycle current limiting (1–1.2 A), thermal shutdown (130–150 °C), and NMOS/PMOS switch leakage < 0.1 µA at 25 °C.

Key Specifications

Pinout & Package

ST2S06D33 is packaged in QFN12L (4×4 mm, 0.9 mm height), thermally enhanced with exposed pad for junction-to-case thermal resistance of 10 °C/W. Pin numbering follows top-view layout with GND pins distributed across corners (GND1, GND2, GND_A) to minimize ground bounce.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST2S06A33PQR, ST2S06D33 offers shorter reset delay (52–78 ms vs. 80–85 ms) and lower reset threshold (4.55 V vs. 4.6 V), improving responsiveness in fast-ramping supplies; versus TPS65023RGTR, it trades rail count and integration for smaller footprint and built-in reset logic-ideal for cost- and space-sensitive dual-rail ODD applications.

Availability

ST2S06D33 is available at Aetrix Electronics and suitable for optical disc drive power management, embedded microcontroller dual-rail supply, and portable media player baseband power requiring stable component supply and long-term lifecycle support.

Supply support for ST2S06D33 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 analog, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

The ST2S06 series belongs to ST's high-efficiency DC-DC converter product line, engineered specifically for replacing linear regulators in space-constrained digital core power applications such as optical storage devices and portable multimedia systems.

FAQ

What is the purpose of the HV pin on ST2S06D33?

The HV pin configures internal reference and enables the reset function in ST2S06D33. It must be left floating or tied to GND; connecting to VIN_SW or other voltages may disable reset or cause undefined behavior. This pin distinguishes D-version functionality from A/B variants and is not used for voltage regulation or feedback.

Can ST2S06D33 operate with input voltage below 4 V?

No-ST2S06D33 is specified for 4–5.5 V input only, as confirmed in Table 7 electrical characteristics. Operation below 4 V violates absolute maximum ratings and causes failure to regulate both outputs; the device lacks under-voltage lockout (UVLO) below 4 V and may exhibit erratic reset or oscillation.

How does the reset delay vary with temperature?

Reset delay (tDEL) decreases with rising temperature: 78 ms at −40 °C, 65 ms at 25 °C, and 52 ms at 125 °C, per Figure 18. This inverse relationship results from internal RC timing network drift and must be accounted for in worst-case power-up timing budgets across industrial temperature ranges.

Is external compensation required for ST2S06D33?

No-ST2S06D33 integrates full internal compensation for both channels, eliminating need for external compensation networks. The current-mode PWM architecture with fixed 1.5 MHz frequency ensures stable operation with standard 3.3 µH inductors and 22 µF X5R/X7R ceramic capacitors without loop tuning.