ST1S06PUR DC-DC converter: Pinout, Features and Datasheet

Pin configuration

The ST1S06xx is a step-down DC-DC converter optimized for powering low-voltage digital core in HDD applications and, generally, to replace the high current linear solution when the power dissipation may cause high heating of the application environment. It provides up to 1.5 A over an input voltage range of 2.7 V to 6 V. An high switching frequency (1.5 MHz) allows the use of tiny surface-mount components: as well as the resistor divider to set the output voltage value, only an inductor and two capacitors are required.

Besides, a low output ripple is guaranteed by the current mode PWM topology and by the use of low ESR SMD ceramic capacitors. The device is thermal protected and current limited to prevent damages due to accidental short circuits. The ST1S06xx is available in DFN6D (3x3 mm) package.

PCB Symbol - STMicroelectronics ST1S06PUR

PCB Footprint - STMicroelectronics ST1S06PUR

3D model- STMicroelectronics ST1S06PUR

■ Step-down current mode PWM (1.5 MHz) DCDC converter

■ 2% DC output voltage tolerance

■ Synchronous rectification

■ Inhibit function

■ Internal soft-start

■ Typical efficiency: > 90 %

■ 1.5 A output current capability

■ Not switching quiescent current: max 1.5 mA over the temperature range

■ RDS(ON) typ.150 mΩ

■ Uses tiny capacitors and inductors

■ Operative junction temp. - 30 °C to 125 °C

■ Available in DFN6D (3x3 mm) exposed pad

STMicroelectronics ST1S06PUR technical specifications, attributes, parameters and parts with similar specifications to STMicroelectronics ST1S06PUR.

Application circuit

Application notes

The ST1S06xx is an adjustable current mode PWM step-down DC-DC converter with an internal 1.5 A power switch, packaged in a 6-lead DFN 3x3.

It’s a complete 1.5 A switching regulator with its internal compensation eliminating additional components.

The constant frequency, current mode, PWM architecture, and stable operation with ceramic capacitors results in low, predictable output ripple. However, in order to maximize the power conversion efficiency with a light load, the regulator reduces automatically the switching frequency when the output load becomes less than 250 mA typically.

To clamp the error amplifier reference voltage a soft start control block generating a voltage ramp, has been implemented. Besides an on-chip power-on reset of 50 = 100 µs ensures the proper operation when switching on the power supply. Other circuits fitted to the device protection are the thermal shut down block which turns off the regulator when the junction temperature exceeds 150 °C typically and the cycle-by-cycle current limiting that provides protection against shorted outputs.

Being the ST1S06xx an adjustable regulator, the output voltage is determined by an external resistor divider. The desired value is given by the following equation:

VO = VFB [1 + R1 / R2]

To make the device working, only a few components are required: an inductor and two capacitors, and the resistor divider. The chosen inductor must be able to not saturate at the peak current level. Besides, its value can be selected keeping in account that a large inductor value increases the efficiency at low output current and reduces output voltage ripple, while a smaller inductor can be chosen when it is important to reduce the package size and the total cost of the application. Finally, the ST1S06xx has been designed to work properly with X5R or X7R SMD ceramic capacitors both at the input and at the output of this kind of capacitors, thanks to their very low series resistance (ESR), minimize the output voltage ripple. Other low ESR capacitors can be used according to the need of the application without invalidating the right functioning of the device.

ST1S06PUR packageDFN6D (3x3 mm) mechanical data