Questions tagged [buck]
A non-isolated DC-DC converter topology which outputs voltage less than or equal to the input voltage
1,268
questions
1
vote
1
answer
38
views
Power Supply Validation - What Matters?
When it comes to validating a power supply (for example, a buck regulator), what parameters matter?
From the research I have done, I think that things such as ripple voltage, percentage overshoot ...
- 601
0
votes
3
answers
66
views
How does soft-start in a buck converter help reduce inrush current
Consider a synchronous buck converter that is off, inductor voltage is 0, capacitor voltage is 0.
The moment the high-side switch is turned on for the first time (no matter for high long). There will ...
3
votes
3
answers
120
views
Using an NMOS for a high-side switch in a buck converter
I know that to use an NMOS as a high side, you need a gate boosting circuit! I am just here to check my understanding on what WOULD happen if I did use an NMOS device without a boosting circuit and ...
0
votes
0
answers
32
views
High-current AC-DC converter [closed]
I'm searching for a SMPS circuit with a 220 Vac input and a 12..80 VDC adjustable output.
The hardest requirement is the maximum output current must be >20 A. Ideally it would be 80 A.
0
votes
1
answer
62
views
Voltage regulator equation
I'm designing a circuit using this buck regulator (AOZ2253TQI-20) from Alpha & Omega. Data sheet here, http://www.aosmd.com/res/data_sheets/AOZ2253TQI-20.pdf
The data sheet doesn't specifically ...
- 19
0
votes
0
answers
63
views
DC DC converter from low voltage to high voltage [closed]
I need your help here. I will be starting a new job where my main tasks would be designing a DC to DC converter with an output of up to 5 to 6 kW.
I have never designed a board with such high power ...
- 21
0
votes
0
answers
26
views
Power issue with NRF24LO1 and ATtiny44
I am super frustrated with my NRF24LO1 module and ATtiny44. The thing is when it is connected to an Arduino board it works perfectly, but when I try powering up using battery the entire system halts.
...
0
votes
1
answer
54
views
Single buck converter for multiple fans with different speeds?
I need to switch a 3d printer motherboard which controls some fans, the new one outputs 24V instead of 5V, but each fan is 5V. Each fan will need to be spun up/down independently from the other two. I ...
- 113
0
votes
2
answers
54
views
Would increasing the load resistance in a buck converter increase efficiency?
I was recently asked in an interview if the efficiency of a buck converter would change based on changing the load resistance (I assumed this meant constant input and output voltage).
I answered that ...
- 1
0
votes
1
answer
54
views
synchronous buck simulation
I got confusing result from hspice simulation but I can't get it.
the voltage at "N1"should be 4V when W1 on,and be 0 when W0 on.
but result is always 0 and pulse of negative voltage.
below ...
- 25
2
votes
2
answers
97
views
Can anyone help me with this delay problem in my UPS circuit?
I am trying to build an UPS for my laptop. My laptop doesn’t have a battery and battery port is damaged, only way I can power my laptop is from the DC port. But the problem is where I live power ...
- 23
1
vote
1
answer
33
views
PSRR of an amp + ADC input stage
I have an input stage that consists of an amplifier then an ADC. The op-amp and ADC are powered by Buck voltage regulators.
I want to measure the PSRR of this stage, so I am planning on breaking the ...
- 39
1
vote
1
answer
48
views
Buck converter bias supply
I am using an MP2325 buck converter (datasheet) to drop a 24v supply down to 5v to supply a Raspberry Pi.
The datasheet above details ...
- 133
1
vote
2
answers
72
views
DC-DC buck converter duty cycle issue [closed]
I want to make DC-DC buck converter with a PWM controller, gate driver, and MOSFET switch. But I can't find the PWM controller that matches my requirements: input voltage 40 V, output voltage 24 V ...
- 53
8
votes
1
answer
132
views
MOSFET failure in a high power AC-DC SMPS buck converter
I've made a AC-DC step down buck converter that converts 220 VAC to a variable 45 to 70 VDC at 5 to 10 A to charge a Li-Ion battery. I'm currently using ESP32 to drive a MOSFET driver (IR2110) to ...
- 81
1
vote
1
answer
47
views
Coupled inductors for multi-output buck
I see coupled inductors are generally used in multi-phase design to take advantage of current ripple cancellation.
What is really the advantage of coupled inductor in multi-output buck or multi-output ...
- 2,051
2
votes
2
answers
395
views
Why use external compensation on a buck IC?
The AP64200, with block diagram of
says about loop compensation that
The goal of loop compensation design is to achieve:
High DC Gain
Gain Margin less than -10dB
Phase Margin greater than 45°
Loop ...
- 2,985
1
vote
2
answers
40
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 ...
- 875
1
vote
3
answers
57
views
Buck converter simulation Vout lower than expected
I am trying to design a simple buck converter in LTSpice. Here are my parameters:
...
- 21
4
votes
3
answers
92
views
STM32 Low Quescient Current Power Supply
I want to find the most efficient way to power an STM32 microcontroller from a lipo (3.7V nominal).
I have calculated that @ 3.3V, the current consumption is approximately:
in run mode:1.75mA
in idle ...
- 363
2
votes
2
answers
103
views
Step down converter with low side MOSFET
I'm trying to gain confidence with electronic as I'm quite new to this world. To get started I began to study a buck converter which I'm simulating with LTspice.
The problem is that the design that I ...
- 23
1
vote
0
answers
36
views
How does the COMP/EN pin of the MAX1967/MAX1966 work?
I know this question may seem simple to more experienced people but I struggle to understand how the COMP/EN pin works on this particular IC.
I want to use it for a buck converter that has external ...
0
votes
0
answers
40
views
Why is my buck converter stimulation not working on proteus?
Why is my proteus stimulation only outputting the voltage and current zero when I connect the ground terminal - shown at the bottom right of the image, when I do not connect the ground terminal the ...
2
votes
4
answers
497
views
What is the difference between voltage regulators, resistors, and buck converters?
I am new to electronics and I would like to know the difference between voltage regulators, resistors and buck converters like the LM2596 and their advantages, disadvantages and use cases.
I tried ...
- 21
0
votes
0
answers
52
views
Flybuck circuit
Needing a dc to dc converter, I thought of using a "flybuck" circuit, I stopped at the IC "AOZ3015AI" (https://www.tme.eu/Document/0262838228a45307035e45b4effa9bb7/AOZ3015AI-DTE....
- 53
1
vote
1
answer
47
views
Reduce the heat output of a MOSFET (buck LM5085)
First of all I have to say that I am a beginner, and I don't have an oscilloscope to work with. Just a multimeter.
I'm trying to design a PoE+ board with a 9.5 V @ 3 A output.
The PoE+ part works fine ...
- 139
1
vote
0
answers
53
views
DC-DC converter/step down layout improvements/feedback
I'm designing a board with a 12V to 5V DC-DC converter circuit and I would like some feedback on how it can be improved. As it is the first time I have designed such a circuit, I'm not the most ...
- 139
2
votes
1
answer
76
views
Buck converter with interleave yields wrong output voltage in simulation
It isn't obvious to me how to solve this by hand (if anyone knows I am very interested), so I thought of simulating it instead. We need to know some values, though:
Duty cycle of switch A \$D_A = \...
- 2,886
1
vote
1
answer
98
views
Buck converter after boost converter -- what is an advantage?
I encountered a mass produced device that has a power circuit like this:
5V from USB ==[boost converter]==> 13V ==[buck converter]==> 12V
and it confused me. I don't see why you would need a ...
- 21
3
votes
0
answers
62
views
Startup transient on LMR14030-Q1 buck converter
So I'm trying to build my first buck converter for an audio project using a TI LMR14030-Q1. My first design had some acoustic noise so I changed the switching frequency, inductor, and output ...
- 131
0
votes
1
answer
58
views
Acceptable overshoot, accuracy, and control bandwidth of a buck converter
I am designing a closed loop buck converter and was wondering what would be the acceptable values/performance for control parameters like accuracy, control bandwidth, and overshoot.
I know that the ...
- 67
1
vote
0
answers
38
views
Buck regulator thermals calculations
Schematic:
Specification:
Vin = 24V
Vout =5V
Iout max = 8A
Freq = 0.691 Mhz
Assumptions: Good layout and FETs mounted on 1-2 inch^2 of copper.
Calculations based on this doc: https://www.ti.com/lit/...
- 539
0
votes
2
answers
103
views
I would like to drop a variable DC voltage from input 30Vdc to 200Vdc to output 5Vdc with a max 200mA
I am new to electronics and would like some help if possible.
The incoming voltage will be variable from 30Vdc to 200Vdc coming from a bank of solar panels. The output is 5vdc at a max of 200mA. I ...
- 11
0
votes
0
answers
54
views
Question on resistor voltage dropper values for VCC supply of LED driver IC
I was designing the PCB for a 10 W LED driver with the AL1676 controller. From the datasheet, the application circuit shows that the driver takes its VCC supply through R1 and R2. The maximum value ...
- 1
0
votes
1
answer
89
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
2
votes
1
answer
194
views
5V and 12V derived from a regulated 12V supply? Buck converter for 5V, in parallel with 12V load?
Apologies up front — this is super basic, but I’m sleep deprived and on a deadline for a personal project.
This is all DC. I have a 12 V input (via a wall-wart). I need 5 V to power some electronics (...
- 132
2
votes
1
answer
121
views
Critical inductance for buck converter
I have this problem: -
The critical current must be \$P_{out} = V_{out}I_{crit} \Rightarrow I_{crit}=\dfrac{45\text{W}}{16\text{V}} = 2.8125 \text{A} \$
Using eq. 3.43 from Ned Mohan's book we have
$$...
- 2,886
0
votes
2
answers
61
views
Input current and output current in boost regulator
How can the input current of a boost regulator be more then the output current of the same regulator when the load has a set current draw.
For example going from 5V to 12V with a load of 2A. The power ...
- 13
3
votes
2
answers
103
views
Adjust regulator to output lower than its feedback reference
I am designing an adjustable high current buck converter.
The input voltage will be around 12V, but the output needs to be adjustable in the range of 0.2 to 10V.
I have decided to use the LM27402 (...
- 1,640
0
votes
1
answer
81
views
Buck Converter Voltage Ripple at Output
I just made a 32V to 16V 2 Amps buck converter with a 10mH inductor, I'm having an issue with the voltage ripple output. Too many spikes, and it's generally not consistent. Electrolytic and Film ...
0
votes
2
answers
85
views
Tricking feedback of a buck converter
I need to trick the buck converter feedback. The converter that I am going to use is TPS40192DRCT.
Instead of the regular resistor divider, I want to feed there voltage proportional to current ...
- 170
4
votes
3
answers
369
views
Switch mode power supply vs DC-DC converter
I have started learning about DC-DC converters and switch mode power supplies (SMPS.) I know that the standard SMPS (attached fig. below) has an input rectifier, DC link capacitor, inverter, output ...
- 67
0
votes
2
answers
36
views
Regulator controller current capability
I am tasked with the design of a board that needs a buck regulator.
This regulator will work on low voltages (Vin ~= 12V, Vout ~= 4V), but high output current is required (> 60A).
I decided to use ...
- 1,640
0
votes
1
answer
33
views
Inductor and specs for a buck converter at low currents - high r
I'm currently designing a buck converter using the AP64501. This issue/question is not specific to that buck however. I have a python script that I wrote that uses the formula's in TI's appnote: AN-...
- 676
2
votes
1
answer
87
views
How to buck 120V DC to 56 DC?
I'm working on a project to power a 56 volt BMS with a buck converter that bucks 120V DC (rectified from 120AC) to 56V DC, but I've gotten to the point where I'm hard stuck.
Here is what I have so far....
3
votes
2
answers
319
views
Frequency Response of Ideal and Real Type III Compensator
I'm trying to develop a Buck Converter with a Voltage-Mode Control, using a Type III Compensator, just like the one below.
So I calculated its transfer function, and then with the correct values of ...
0
votes
1
answer
51
views
Inductor position in low side buck converter
I am designing a PCB to control an RGBW-LED. To provide a regualted current for each color I am using the LM3407 buck converter from TI. The buck converter is powered with 12V and is configured to ...
- 255
1
vote
0
answers
51
views
Buck converter driver LTC4446 running too hot, too high current
I am trying to design a buck converter, but the driver LTC4446 is getting to hot with this design and the input current is also to high (130 mA), when it should be in the uA orders... Any ideas of why ...
0
votes
1
answer
65
views
Buck converter: Additional circuitry working not clear
Saw the below schematic of a buck converter, but not able to figure out the working of the marked section. It is shown Node 1 is at 16 V.
Looks like sensing the differential voltage across inductor, ...
- 2,051
2
votes
0
answers
87
views
Is it true that power supply design is difficult when input voltage range is wider?
During power supply (buck converter) testing, I had seen the lowest efficiency values corresponding to highest input voltage. I thought if the design meets this worst case scenario, it should be ok no ...
- 2,051