All Questions
59
questions
-1
votes
1
answer
143
views
Buck converter load voltage drop
I'm creating a buck converter from a NE555 and LM358 (feedback loop) for powering a tablet motherboard. (This is a learning experience for me, don't want to use an off-the-shelf board.)
Here is the ...
- 103
0
votes
1
answer
1k
views
24V to 5V step down voltage regulator with LM2678 [closed]
Reference: https://www.ti.com/lit/ds/symlink/lm2678.pdf
I have constructed the circuit above attempting to step down the DC voltage from 24V to 5V. But I keep getting 8.3V as the output voltage. It is ...
- 11
1
vote
2
answers
76
views
Improve thermal effeciency of buck LED driver with fixed supply rail
I have this driver circuit that uses an ILD8150:
There are two identical sections of this module on my PCB.
One powers 6 LEDs the other powers only 2 LED. The Vf of the LEDs is 2.85V @ 350 mA.
So the ...
- 1,235
0
votes
1
answer
596
views
Step down buck converter - lower input voltage than output - LM2596
I want to power 5v leds from a 12v source in my car using a "DC-DC Adjustable Step-down Buck Converter LM2596 3A". The source has a dimmer switch which can regulate the voltage from 12v to 1....
- 1
3
votes
0
answers
180
views
LM3150 Webench not matching with LTSpice?
I'm trying to implement this design from Webench (5V @ 10A):
I'm using LTspice to simulate this design, but my results are bizarre, as shown here:
I have looked into this thread: TI Webench and ...
- 31
0
votes
1
answer
365
views
Step-down converter in an ATX PSU, why?
I was recently looking at a 500W PSU schematic, and found out they used step-down converters on 12v and 5v output. Schematic is attached(pls see hi-res at https://ibb.co/nbDRJPq)
The D2 diode charges ...
- 392
-1
votes
2
answers
273
views
Buck / step down voltage in limited space
I am designing a small PCB. The supply voltage is 12V, but I also need 5V with supply of maximum 250mA.
The most obvious solution is to use voltage regulator - there are plenty of them and some like ...
- 555
2
votes
1
answer
704
views
Switching regulator vs converter
Is there any difference between switching regulators and converters? I have read about step-down voltage regulator and buck converters and they seem to be the same. So, can I use the term converter ...
- 37
1
vote
1
answer
1k
views
What is the difference between buck and step-down converter
I always thought "buck" and "step-down" are synonyms. But now I'm looking at two datasheets:
CAT4201
CAV4201
They seem very similar, but the first is described as "350 mA ...
- 1,235
1
vote
0
answers
101
views
How to select external components for a buck converter?
I design a simple circuit activates fan when processor heats up and then control rotation speed. The fan has a brushless motor with an internal motor controller. So I got the idea to create a buck-...
- 21
1
vote
0
answers
658
views
Buck converter (TPS54331) oscillating
I have designed and built a buck converter based on the TPS54331 which oscillates at 5.4kHz with an amplitude of 700mV peak-to-peak under a 1A load. I want to remove these oscillations.
Here is a ...
0
votes
1
answer
1k
views
Understanding Power Good Signal in TPS54719
I'm using TI TPS54719 DC-DC and I'm trying to understand the PWRGD signal functionality.
Definition of PWRGD pin in datasheet: An open drain output, asserts low if output voltage is low due to thermal ...
- 1,067
0
votes
1
answer
130
views
Converting 12 Volt Lipo to 5V with Buck Convertor
I'm trying to power a large bank of LEDs that require 5V at 5 amps. I plan to use a 12v hobby Lipo attached to a buck convertor to step that down. I also need to power a teensy microcontroller with ...
1
vote
2
answers
322
views
Do I need to include overhead when picking a power supply?
I need to power 40 Raspberry Pis, each requiring a 5V input and have a maximum current draw is 2.5A.
This would mean:
5 x 2.5 = 12.5W
12.5W x 40 = 500W
That I ...
- 408
0
votes
0
answers
166
views
How to reduce noise Buck converter at constant current mode ACT4088
Hello i am using a ACT4088US-T (datasheet here) Buck converter and i made it to run in constant current mode 500[mA] through a Diode (D5):
Everything works fine. It draws 500mA no matter the load i ...
- 3,404