ST1S03:1.5 A, 1.5 MHz adjustable, step-down switching regulator

The ST1S03 is a step-down DC-DC converter optimized for powering a low voltage digital core in HDD applications and, generally, to replace the high current linear solution when the power dissipation may cause a high heating of the application environment. It provides up to 1.5 A over an input voltage range of 3 V to 16 V. A 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, a Schottky diode 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 an accidental short-circuit. The ST1S03 device is available in a DFN6D package.

Key Features

  • Step-down current mode PWM (1.5 MHz) DC-DC converter
  • 2% DC output voltage tolerance
  • Internal soft-start for STARTUP current limitation and power on delay of 50 - 100 μs
  • Typical efficiency: > 70% over all operating conditions
  • 1.5 A output current capability
  • Not switching quiescent current: max 2.5 mA over temperature range
  • Switch VDS : max. 350 mV at ISW = 750 mA
  • Uses tiny capacitors and inductors
  • Available in DFN6D 3 x 3 mm package with exposed pad
Product Specifications
DescriptionVersionSize
DS4126: 1.5 A, 1.5 MHz adjustable, step-down switching regulator7.0596 KB
Application Notes
DescriptionVersionSize
AN2837: Positive to negative buck-boost converter using ST1S03 asynchronous switching regulator1.0537 KB
AN2093: ST1S03 buck converters for HDD power supplies2.4232 KB
Design Notes & Tips
DescriptionVersionSize
DN0011: ST1S03 alternative topology: Using a buck in a negative buck-boost configuration1.1359 KB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Solution Evaluation Tools
Part NumberManufacturerDescription
STEVAL-ISA042V21.5 A / 3.3 V step-down DC-DC converter demonstration board based on the ST1S03
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
ST1S03PURVFDFPN 6 3x3Tape And Reel0.5661000NECEAR99PHILIPPINES
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
ST1S03PURVFDFPN 6 3x3IndustrialEcopack2md_yg-wspc-vfdfpn-wspc-6-wspc-3x3-wspc-0,95-wspc-pitch_mlygul97af5-wspc-(st1s03pur)-wspc-ver2_signed.pdf
md_yg-wspc-vfdfpn-wspc-6-wspc-3x3-wspc-0,95-wspc-pitch_mlygul97af5-wspc-(st1s03pur)-wspc-wcp-wspc-ver2.xml
1.5 A, 1.5 MHz adjustable, step-down switching regulator ST1S03
circuit_diagram_10992_thumbnail.png ST1S03
Positive to negative buck-boost converter using ST1S03 asynchronous switching regulator ST1S03
ST1S03 buck converters for HDD power supplies ST1S03
ST1S03 alternative topology: Using a buck in a negative buck-boost configuration L5986
Very low drop voltage regulators with inhibit KFXX
md_yg-wspc-vfdfpn-wspc-6-wspc-3x3-wspc-0,95-wspc-pitch_mlygul97af5-wspc-(st1s03pur)-wspc-ver2_signed.pdf ST1S03
md_yg-wspc-vfdfpn-wspc-6-wspc-3x3-wspc-0,95-wspc-pitch_mlygul97af5-wspc-(st1s03pur)-wspc-wcp-wspc-ver2.xml ST1S03