Table of Contents
ST1S41 DC-DC step-down converter module circuit. Powerful 4 A DC-DC step-down switching regulator, with high PWM frequency and low ripple. Can be controlled by an external controller via the Enable input. Able to produce 100% duty cycle and work effectively at low and high loads. The efficiency of the chip increases due to its synchronous circuit and a p-channel high-side MOSFET and thanks to this it can continuously keep it open without needing a bootstrap capacitor. Excellent chip for adjusting the output voltage from 0.8V to the Vin.
The ST1S41 is an internally compensated 850 kHz fixed-frequency PWM synchronous step-down regulator. The ST1S41 operates from 4.0 V to 18 V input, while it regulates an output voltage as low as 0.8 V and up to V IN. The ST1S41 integrates 95 mΩ high-side switch and 69 mΩ synchronous rectifier allowing very high efficiency with very low output voltages. The peak current mode control with internal compensation delivers a very compact solution with a minimum component count. The ST1S41 is available in VFQFPN 4 mm x 4 mm 8-lead package and HSOP-8.
Schematic circuit ST1S41 DC-DC step-down converter module
Features ST1S41 DC-DC step-down converter module
- 4 A output current
- 4.0 V to 18 V input voltage
- Output voltage adjustable from 0.8 V
- 850 kHz switching frequency
- Internal soft-start
- Integrated 95 mΩ and 69 mΩ power MOSFETs
- All ceramic capacitor
- Enable
- Cycle-by-cycle current limiting
- Current foldback short-circuit protection
- VFQFPN 4×4-8L and HSOP-8 packages
Pin description
| N. | Type | Description |
| 1 | VINA | Unregulated DC input voltage |
| 2 | EN | Enable input. With EN higher than 1.2 V the device in ON and with EN lower than 0.4 V the device is OFF (ST1S41lxx). |
| 3 | FB | Feedback input. Connecting the output voltage directly to this pin the output voltage is regulated at 0.8 V. To have higher regulated voltages an external resistor divider is required from Vout to FB pin. |
| 4 | AGND | Ground |
| 5 | NC | Can be connected to ground |
| 6 | VINSW | Power input voltage |
| 7 | SW | Regulator output switching pin |
| 8 | PGND | Power ground |
| 9 | ePAD | Ground |
BOM ST1S41 DC-DC step-down converter module
| Parts | Value | Description | Quantity |
|---|---|---|---|
| Resistors | |||
| R1 | 56K (563) | R0805 – SMD resistor | 1 |
| R2 | 25K (253) | 3296W trimpot | 1 |
| R3 | 100k (104) | R0805 – SMD resistor | 1 |
| Capacitors | |||
| C1,C2,C4,C5 | 22uF | C1210 – SMD capacitor | 4 |
| C3 | 1uF | C0805 – SMD capacitor | 1 |
| C6 | 100uF/25V | Electrolytic capacitor | 1 |
| C7 | 33pF | C0805 – SMD capacitor | 1 |
| Semiconductors | |||
| U1 | ST1S41PUR | Step-down type Adjustable 4A 4V~18V 800mV~18V VFQFPN-8L(4×4) DC-DC Converter |
1 |
| Miscellaneous | |||
| H1 | EN | 1x2P 2.54mm Female Header | 1 |
| J1 + J2 | GND, VCC | 1x2P 2.54mm pin Header | 2 |
| J3 + J4 | GND, OUT | 1x2P 2.54mm pin Header | 1 |
| L1 | 3.3uH | 5.3A SMD,4.1×4.4mm Power Inductor | 1 |
Download files, links, and notes
- Download PCB in Gerber + BOM + Centroid file + PDF + PNG + SVG + OBJ 3D file
- Mirror
- BUY DC DC converter
- BUY ST1S41PUR chip
- PDF datasheet ST1S41
- Component values calculation
- Buck Converter Design Note DN 2013-01
- Optimizing Transient Response of Internally Compensated dc-dc Converters with Feedforward Capacitor
Source: https://oshwlab.com/sneer2sneer/ST1S41-DC-DC-Regulator
