Overview
The ST1S50PUR, produced by STMicroelectronics, is a 500 kHz fixed frequency PWM synchronous step-down regulator. This device is designed to operate from an input voltage range of 4.0 V to 18 V and can regulate an output voltage as low as 0.8 V up to 0.88 times the input voltage. It integrates high-efficiency power MOSFETs, including a 95 mΩ high-side switch and a 69 mΩ synchronous rectifier, enabling high efficiency even at very low output voltages. The ST1S50PUR is packaged in a VFDFPN10 3 x 3 x 1 mm - 10 leads package, making it suitable for various point-of-load applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 4.0 to 18 | V |
| Output Current | 4 | A |
| Output Voltage Range | 0.8 to 0.88 x VIN | V |
| Switching Frequency | 500 kHz | kHz |
| High-Side Switch On Resistance | 95 mΩ | mΩ |
| Low-Side Switch On Resistance | 69 mΩ | mΩ |
| Maximum Duty Cycle | 88% | % |
| Operating Junction Temperature Range | -40 to 150 | °C |
| Thermal Shutdown Temperature | 150 °C | °C |
Key Features
- High efficiency at light load due to peak current mode control with a special PFM mode.
- Programmable soft-start and enable to avoid inrush current during startup.
- Integrated 95 mΩ high-side switch and 69 mΩ synchronous rectifier.
- All ceramic capacitor compatibility.
- Power Good (PG) pin for monitoring output voltage.
- Cycle-by-cycle current limiting and short-circuit protection.
- Hysteretic thermal shutdown to prevent thermal runaway.
Applications
- Point of load for set-top boxes (STB), TVs, and gateways.
- Solid state disk drives, Blu-ray, and DVD players.
- Microprocessor (μP), ASIC, DSP, and FPGA core and I/O supplies.
Q & A
- What is the input voltage range of the ST1S50PUR? The input voltage range is from 4.0 V to 18 V.
- What is the maximum output current of the ST1S50PUR? The maximum output current is 4 A.
- What is the switching frequency of the ST1S50PUR? The switching frequency is 500 kHz.
- What type of MOSFETs are integrated in the ST1S50PUR? The device integrates a 95 mΩ high-side switch and a 69 mΩ synchronous rectifier.
- What is the purpose of the Power Good (PG) pin? The PG pin is used to monitor the output voltage and is pulled low when the output voltage is lower than 91% of the nominal internal reference.
- How does the soft-start feature work in the ST1S50PUR? The soft-start is programmed by a capacitor connected to the EN_SS pin, which ramps the reference voltage of the error amplifier to avoid inrush current during startup.
- What is the thermal shutdown temperature of the ST1S50PUR? The thermal shutdown temperature is 150 °C.
- What type of protection does the ST1S50PUR have against overcurrent? The device has cycle-by-cycle current limiting and short-circuit protection.
- What is the package type of the ST1S50PUR? The device is packaged in a VFDFPN10 3 x 3 x 1 mm - 10 leads package.
- What are some typical applications of the ST1S50PUR? Typical applications include point of load for STB, TVs, gateways, solid state disk drives, Blu-ray, DVD players, and μP/ASIC/DSP/FPGA core and I/O supplies.
