21
votes
Why should I route the feedback trace under the output capacitor?
The reason for this is that there's a very large ripple current flowing from the output inductor down into the output filter capacitor. The trace between these two isn't perfect (it has resistance and ...
- 15.5k
11
votes
Accepted
Why should I route the feedback trace under the output capacitor?
I doubt it matters.
Appnotes love to go overboard with layout instructions, but without explaining what and why; let alone giving quantitative values, or comparing alternative layouts with ...
- 27k
5
votes
Accepted
Tantalum capacitors in synchronous DC/DC converter
It is not necessary to use a tantalum. Generally, for the input side ceramic capacitors are sufficient, combined with bulk electrolytic or Al-polymer if needed to handle load transients.
The DC-DC ...
- 51.1k
2
votes
Accepted
Running a TV Using Only Solar Panel, Without a Battery
Quick observations: looks to be pretty well designed, though you haven’t put in didoes to protect the PV panels (not sure if they’re in the PV panels, they may be already fitted). You haven’t looked ...
- 4,086
2
votes
I want to control the voltage and current of a LTC3780 module using an Arduino
There are a ton of Chinese modules that say they use the LTC3780. Without more information (specifically, a good schematic) it's hard to say exactly what could go wrong. The pricing suggests the ...
- 383k
2
votes
Do I need to add a filter for an isolated DC-DC converter?
The test configuration is a circuit that is used to test the performance of the DC-DC converter under controlled conditions. It is not necessary to use the test configuration for normal operation of ...
- 29
2
votes
Clock Driver - What's wrong with my H-bridge design?
Q1 dies because its gate-source voltage goes outside its limits. As you can see from the datasheet, its maximum allowed gate-source voltage is ±12V.
But once you enable it, the gate-source sees -24V (...
- 30.2k
2
votes
How to tell if buck converter outputs are isolated?
A buck converter is per definition not isolated.
For the broader term of converter being able to down-regulate but with transformer (and transformer ratio), it would be a forward type converter.
- 13.7k
2
votes
Accepted
Sampling gain effect in buck converter
Let me try to give a simple answer to this question. Current-mode-controlled converters are made of two loops: an inner current loop and an outer loop which ensures voltage regulation. The error or ...
- 20.9k
1
vote
Sampling gain effect in buck converter
Pulse width modulation used in the control of power supplies essentially causes a phase delay in the loop, similar to the sampling delay in a pure digital system. When the inernal ramp voltage reaches ...
- 132
1
vote
Building a constant current circuit
The best circuit for a fine-tunable constant current source would be a Howland Current Pump. There are various versions of it, and the version I prefer using in particular is the following:
Image ...
- 326
1
vote
Boost converter output instability
Yes, this will happen on your design because without input current limiting (or an inductor bypass circuit) the initial transient of supply voltage will form an RLC low-pass filter of fairly decent Q ...
- 443k
1
vote
Circuit to convert 14.8v battery with max 4a discharge current into 12v, 9v and 5v output?
To reduce unwanted interactions (e.g., motor noise vs. control circuits), it's an advantage to have three separate power supplies.
One might derive a 5 V supply from the 12 V rail with resistors and ...
- 3,789
1
vote
Can you power 2 voltage rails simultaneously using a buck-boost converter?
You can use a linear regulator along with a boost converter to get 3.3V and 5V respectively.
- 153
1
vote
Accepted
Boost converter duty cycle
This is my thought process, run Pavg equation for the diode. I’m
getting 714 A. Don’t think my setup is correct.
It won't be anywhere 714 amps. If the forward volt drop is 0.7 volts then, if ...
- 443k
1
vote
Accepted
5V USB-Power without Battery makes MCP73832T toggle the LED
Most likely C2 is the problem. When the battery is not connected, the MCP wrongly thinking there's a battery due to C2, so it drives Stat low (turning the LED on) then it very quickly charges the ...
- 1,995
1
vote
Accepted
Can I use one 12 V 8 A power supply to provide 5 V 10.5 A power via buck converters?
That will work just fine. The buck converters will need to be at least 52.5/96 = 54.7% efficient, which is such a low requirement that practically any buck converter on the planet can do it.
The Pi 4B ...
- 15.5k
1
vote
Buck converter with external reference voltage?
Probably more complex than you'd like but the LTC3886 can be digitally programmed (I2C). It has 12-bit digital programmability of output voltage of 2 to 13.8V in 4mV steps and 16-bit digital readback ...
- 383k
1
vote
Why have 3 AAA batteries not one AA and raise voltage (how expensive is it to raise voltage from 1.5 to 5v)?
I offer an alternative solution here, which worked for me.
I have a head torch that I use on the bike, designed to run off 3xAA cells. It works just as well with 1.2V NiMH cells as it does with 1.5V ...
- 2,541
1
vote
Why have 3 AAA batteries not one AA and raise voltage (how expensive is it to raise voltage from 1.5 to 5v)?
White LEDs run at around 3V. the current will depend on the size of the LED. For example, 0.33A for a 1W LED, or 1A for a 3W LED.
It's certainly possible to boost the voltage from a 1.5V cell to 3V ...
- 18.9k
1
vote
How can I amplify an analog DC voltage signal?
Subtract 0.6V and scale by 9 and add 1V.
Or in math terms:
VOut = (VIn - 0.6V)x9 + 1V-> Vout [1;10]V with Vin [0,6;1,6]V
Or in circuit terms:
simulate this circuit – Schematic created using ...
- 3,051
Only top scored, non community-wiki answers of a minimum length are eligible