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0-30V, 0-7A Adjustable Switching Power Supply


DC to DC buck converters is a famous topology in the electronic and a widely used circuit in electronic devices. A buck converter steps down the input voltage while it increases the output current. In this article/video, I have discussed a DC to DC buck converter that can be used effectively as a switching power supply. The output voltage and current are adjustable: 1.25V to 30V and 10mA to 6A (continuous). The power supply supports the constant voltage (CV) and constant current (CC) features. Two LEDs demonstrate the CV and CC status. The circuit is compact and both sides of the PCB have been used to mount the components.

To design the schematic and PCB, I used Altium Designer 21, also the SamacSys component libraries (Altium plugin) to install the missing schematic symbols/PCB footprints. To get high-quality fabricated PCB boards, I sent the Gerbers to PCBWay.

To test the circuit, I used the power analysis feature of the Siglent SDS2102X Plus oscilloscope (or SDS1104X-E), Siglent SDL1020X-E DC Load, and Siglent SDM3045X multimeter. Isn’t cool, so let’s get started!


Input Voltage: 8V to 35VDC
Output Voltage: 1.25V to 32VDC
Output Current (continuous): 10mA to 6A
Output Current (short period): 7A to 8A
Output Noise (no load): 6mVrms (9mVp-p)
Output Noise (6A load): 7mVrms (85mVp-p)
Output Noise (6A load, 16P-average): 50mVp-p
Efficiency: up to 96%

The output noise, 5A load, 20MHz BW limit

Not bad.  How about input ripple?


--- Quote from: T3sl4co1l on September 22, 2021, 03:02:00 pm ---Not bad.  How about input ripple?

--- End quote ---

I don't remember the exact figure, however, it was higher than the output.


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