Overview
The ST1S40IPHR is a 3 A DC step-down switching regulator produced by STMicroelectronics. This device is an internally compensated, 850 kHz fixed-frequency PWM synchronous step-down regulator. It operates from an input voltage range of 4.0 V to 18 V and can regulate output voltages as low as 0.8 V. The ST1S40IPHR integrates high-efficiency power MOSFETs, including a 95 mΩ high side switch and a 69 mΩ synchronous rectifier, ensuring very high efficiency even at low output voltages. The device features peak current mode control with internal compensation, which provides a compact solution with a minimal component count.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 4.0 to 18 | V |
| Output Current | 3 | A |
| Switching Frequency | 850 kHz | |
| Output Voltage Range | 0.8 to VIN | V |
| High Side Switch ON Resistance | 95 mΩ | |
| Low Side Switch ON Resistance | 69 mΩ | |
| Maximum Limiting Current | 4.0 to 6.0 | A |
| Operating Junction Temperature Range | -40 to 150 | °C |
| Storage Temperature Range | -55 to 150 | °C |
| Package Types | HSOP-8, VFQFPN 4x4-8L, SO8 |
Key Features
- Internal soft-start to limit inrush current during startup
- Integrated 95 mΩ high side switch and 69 mΩ synchronous rectifier for high efficiency
- Peak current mode control with internal compensation for stability
- Cycle-by-cycle current limiting and current fold back short-circuit protection
- All ceramic capacitor compatibility
- Enable input for device control
- Thermal shutdown to prevent thermal runaway
- Compact solution with minimal component count
Applications
- Microprocessor, ASIC, DSP, and FPGA core and I/O supplies
- Point of load for set-top boxes, TVs, DVD players
- Optical storage devices, hard disk drives, printers
- Audio and graphic cards
Q & A
- What is the input voltage range of the ST1S40IPHR?
The input voltage range is from 4.0 V to 18 V. - What is the maximum output current of the ST1S40IPHR?
The maximum output current is 3 A. - What is the switching frequency of the ST1S40IPHR?
The switching frequency is 850 kHz. - How is the output voltage adjusted on the ST1S40IPHR?
The output voltage can be adjusted by connecting an external resistor divider from Vout to the FB pin. - What are the package options for the ST1S40IPHR?
The device is available in HSOP-8, VFQFPN 4x4-8L, and SO8 packages. - Does the ST1S40IPHR have built-in overcurrent protection?
Yes, it features cycle-by-cycle current limiting and current fold back short-circuit protection. - What is the purpose of the soft-start feature in the ST1S40IPHR?
The soft-start feature is essential to avoid inrush current surge and ensure a safe and monotonic increase in output voltage during startup. - How does the thermal shutdown feature work in the ST1S40IPHR?
The thermal shutdown feature prevents thermal runaway by shutting down the device if the junction temperature exceeds 150°C. - What types of capacitors are recommended for use with the ST1S40IPHR?
All ceramic capacitors are compatible with the ST1S40IPHR. - What is the quiescent current of the ST1S40IPHR when the device is in standby mode?
The total standby quiescent current is 2 to 15 µA.
