Questions tagged [buck]
A non-isolated DC-DC converter topology which outputs a voltage less than or equal to the input voltage.
1,663
questions
1
vote
1
answer
92
views
Custom buck converter putting out 1V instead of 5V
I "designed" a simple buck converter, which is basically a clone of the 5V reference design in the TPS6293x datasheet. Unfortunately, my converter is only putting about 1V (closer to 0.95V). ...
- 25
0
votes
0
answers
73
views
How to make a hight power strobe light (ACL) with arduino and high power LED
I'd like to make a high power strobe anti collision light (ACL) for aviation.
The available power source is 12 - 13 V DC.
The strobe pattern should be programmable / adjustable, therefore an arduino ...
0
votes
1
answer
84
views
Circuit to convert 14.8v battery with max 4a discharge current into 12v, 9v and 5v output?
I am making a robot with multiple devices mounted on top. I am planning to buy either a 14.8v or 11.1v Li-ion battery which has internal BMS limiting maximum discharge current to 4A. Now I need 9v for ...
- 45
0
votes
0
answers
52
views
How to measure Buck LED driver efficiency
I've build a custom LED driver based on a DC/DC Buck converter with a current feedback loop. It works pretty well, the calculated efficiency shall be somewhere around 95%, but I'm struggling with ...
1
vote
1
answer
69
views
AOZ2261 buck switching regulator doesn't give reasonable output
I am designing a brushed motor driver unit that controlled with a ln STM32F410 microcontroller and a DRV8243S H-bridge driver. I am using an AOZ2261NQI-12 to supply the H-bridge driver.
The IC is ...
0
votes
0
answers
53
views
Solver settings for buck converter simulation in simulink
I am trying to simulate a buck converter in simulink to operate at a 200 kHz switching frequency.
The compensator settings that I am using are shown below -
The desired input and output voltages are ...
0
votes
1
answer
111
views
Can I use one 12 V 8 A power supply to provide 5 V 10.5 A power via buck converters?
I want to power four 5 V devices via a single 12 VDC 8 A (96 watt) supply using a buck converter for each device.
I know I could try and redo my circuit but this means disconnecting and rewiring just ...
1
vote
1
answer
120
views
Using capacitor with voltage rating close to input voltage
I am using a buck converter in my design. The input voltage is 12V and output voltage is 5V.
The capacitor C331 and C332 are 10 uF 25 V in 1210 package. The inventory have already 16 V 0805 capacitors....
- 2,593
1
vote
1
answer
209
views
Using a capacitor to handle the inrush surge power of a fridge
I have a household mini fridge connected to my off grid electrical system, and recently I bought a smaller inverter just for the fridge so that I can turn my larger inverter off to reduce power ...
- 11
0
votes
3
answers
289
views
Buck converter with external reference voltage?
I would like to have a buck converter that takes in a reference voltage, and outputs the same voltage.
This is assuming that I'm giving it a Vin that's high enough to support the output voltage that I ...
1
vote
1
answer
186
views
Can I connect buck boost converters back to back?
I need to power a Bluetooth speaker (Beatbox Portable) with a battery pack while also allowing DC power in.
I also want to use the input DC power to charge the four cell lithoum ion battery pack.
Can ...
- 11
1
vote
0
answers
62
views
Unable to find Gvd of a buck converter using LTspice
I'm trying to simulate a closed-loop buck converter in LTspice. I'm using ideal components. I started by finding the Gvd of the buck converter (duty to output transfer function). I used the .ac ...
0
votes
0
answers
44
views
Parallel MPPT and buck with PV to power an ESP32 via USB
I have a 100w 20v 5A PV that is being used to charge a 72v SLA pack. The MPPT has the 12v-60v input and output 24v-72v range I need. It doesn't have a USB port built in though.
I'd like to have this ...
- 21
2
votes
2
answers
308
views
What is the purpose of the Zener diode in this voltage smoothing circuit?
I was watching this video and he was explaining that this part of the circuit was to smooth out the voltage to make it stable enough to drive the MOSFETs. Just looking at it, I see it's just an RC low ...
0
votes
1
answer
574
views
TL494 step-down converter high voltage LTSpice
I have tried to make LTSpice of step down DC-DC converter, however I cannot get it to work. I suspect the schematic is good however either LTSpice model is not correct or I made some critical mistake.
...
- 145
0
votes
2
answers
168
views
Synchronous buck converter using gate driver IC
I designed synch. buck converter by using gate driver, MOSFETs, inductor and capacitors. I am currently testing in open-loop configuration and later I will test in closed-loop with microcontroller as ...
- 55
2
votes
2
answers
701
views
How much charging ripple voltage is allowed while charging a LiFePO4 battery?
We are designing a buck controller to charge a LiFePO4 battery (4 series 9 parallel cells, each of 3.2 V).
Hence, we would like to charge the battery pack with 13.90 V but the buck output has got a ...
- 29
0
votes
1
answer
94
views
How to divide 12V/15A buck converter output into two outputs with the same specs? [closed]
I am currently working on a project to build a mini-atx pc for a rover. Heres a simple schematic of it :
The picoPSU Atx connector takes in 12V DC with a max of 15A peak and the zotac gpu 12V DC with ...
0
votes
0
answers
20
views
Deriving Power Budget for SAMA5D27C from Datasheet
I am spec'ing out my power distribution network and trying to figure out what Buck converters I am going to need for a Microchip MPU design using SAMA5D27C. I am looking through the data sheet below ...
- 145
1
vote
1
answer
125
views
Burning sound from the PSU
I am trying to make a bench power supply from an old 350W PC PSU
that provides 4 lines
3.3V 8A
5V 9A
12V 11A
-12V 1.5A
Here is the connections diagram:
I used this step down module to be able the ...
1
vote
1
answer
88
views
Is it possible to use BQ25629 as both a lipo battery charger and a stable output regulator?
I am a bit confused looking at the datasheet for the TI BQ25629 with regards to the SYS output voltage. Essentially, I have a 3.7 nominal voltage 290 mAh lipo battery that needs to provide around 100 ...
- 229
2
votes
0
answers
120
views
Power circuitry not coming up
I've created a PCB that has two buck/boost converters, the second one being connected to the output of first one. The enable pin of the second buck converter is connected to the PG pin of the first ...
- 163
0
votes
0
answers
180
views
Untraceable datasheets of DC-DC buck converter (5 pin SOT23-5 IC) used in TP-LINK WiFi Router TL-WR720N V2
I am trying to search the datasheets of DC-DC buck converters used in the TP-LINK WiFi Router TL-WR720N V2.
LD5AX and
TR5XF
A couple of years ago, an above mentioned router, belonging to one of my ...
- 1
0
votes
0
answers
76
views
DC-DC current mode control frequency behavior
On a buck converter in average current control mode, for example, the inner current loop sees and manages the double pole created by the LC filter, and thanks to this the outer voltage loop is blind ...
- 324
0
votes
3
answers
340
views
Am I configuring the IR2104 incorrectly?
I'm trying to make a buck converter using IR2104 and IRFZ44N. The buck converter is controlled using Arduino's PWM. I'll post my schematic below.
Based on the datasheet, the HO signal will be the same ...
0
votes
1
answer
130
views
Buck converter not behaving as anticipated with new trim pot resistors
I recently purchased a 300W buck converter from amazon 1 which has two 3296W 100K trim pots to control the constant current and constant voltage output. My plan was to use them as bench power supply ...
- 131
2
votes
3
answers
259
views
Inductor in buck converter
I have a couple of questions regarding the switching inductor in a buck converter.
Is it normal for the switching inductor in a buck converter to heat up?
In my circuit, it reaches around 65 Celsius. ...
- 345
1
vote
1
answer
65
views
How to set current on a cvcc?
I got a cheapo cvcc off ebay.
Setting volts is pretty easy. I just hook my multimeter leads to the output and twist.
But, how do I set amps? I need something to dump the current in. What should I dump ...
- 135
0
votes
0
answers
76
views
Fully Differential OTA
Based on the figure below, could you explain how a differential ota works ? how can I get the transfert function if I want to set a pole or a zero at the output with a differential resistor and a ...
- 324
2
votes
1
answer
144
views
MPQ4470-AEC1 Layout guideline clarification
I am using MPQ4470-AEC1 in my design. In the datasheet page no 18 contains the layout guidelines.
I have some questions about guideline no:2 and no:3 .Those guidelines are given below.
Place input ...
- 2,593
1
vote
1
answer
233
views
What are the consequences of small bootstrap resistor (in DC-DC buck/step down specifically)?
If I understand it correctly, a bootstrap capacitor (CB) is used to store energy to turn on the high-side MOSFET (P-channel MOSFET). In DC-DC buck converters (which I use now) this happens several ...
- 3,404
1
vote
0
answers
288
views
Modifying XL4015 CC/CV Buck Converter for Undervoltage Lockout
I am trying to convert a XL4015-based CC/CV buck converter module to CV with undervoltage lockout. At this point I am hoping someone can double check my schematic for glaring errors before I attempt ...
- 11
1
vote
1
answer
109
views
Buck converter: PWM modulator input waveform
I have a question about the pwm modulator in a classical buck converter in voltage mode control (VMC). For the circuit in question, I copied over the picture provided in the answer of another SE ...
- 1,041
0
votes
2
answers
153
views
Voltage not varying with duty cycle
I want to make a circuit that changes voltages with the duty cycle as well as doubles that for me. I therefore made a voltage doubler circuit along with alternating PWM wave. But as I changed the duty ...
- 669
7
votes
3
answers
801
views
What technical progress enabled high-efficiency charge pumps?
I found a lot of information on the internet, most of which told me that charge pumps are only suitable for low-power scenarios and they are not very efficient.
Charging ICs based on the charge pump ...
- 73
1
vote
1
answer
73
views
Power dissipation formula
Is the below formula, present on page 26 of this buck converter correct to use?
Or should I use the formula mentioned in the 3 paragraph of this accepted answer?
- 1
1
vote
1
answer
114
views
Non-synchronous buck ASIC's diode selection makes sense?
While selecting buck converter ASIC for a design I came across various synchronous and non-synchronous buck converter from different manufacturers. Synchronous buck are OK - no problem with SW node ...
- 166
1
vote
1
answer
147
views
Buck converter inductor ripple current percentage
I am designing a buck converter using LMR36015 (Texas Instrument). The specifications are:
Input voltage: 24V (+/-10%) = 21.6-26.4V
Output voltage: 3.3V
Output current: 0.4A
Fsw = 1MHz
This leads to ...
- 485
4
votes
2
answers
387
views
Safety circuit for N-channel MOSFET failure (internal short) of buck converter
Consider the following simple low-side N-channel MOSFET based buck converter:
One of the dangerous situations for the load connected to this kind of buck converter (especially if the load is a ...
- 63
2
votes
0
answers
47
views
Double frequency buck converter - minimum values of smaller and larger inductances
Consider a double frequency buck converter shown below having small and large inductors operating at higher and lower switching frequencies respectively, in order to improve both the transient ...
- 61
1
vote
0
answers
105
views
The best way to step down 12V to 5V with at least 10A current from a PS3 power supply for a WS2812B LED strip
I am new to electronics. I had a PS3 Super Slim power supply lying around, which outputs 12V up to 13 amps. Recently, I bought a 5-meter strip of WS2812B LED strip, which needs 5V, and the recommended ...
0
votes
1
answer
49
views
Custom PCB based on LM2596SX-3.3 shorting out
I designed a custom pcb based on this https://github.com/azrael783/esphome_garagedoor_opener and this https://github.com/jampez77/garage_door_sensor for esphome/homeassistant
I nailed the esp part but ...
- 1
1
vote
3
answers
113
views
Unable to start and run 12 V DC pump, only jolts
I have a 12V 19 watt DC water pump (800LPH), A 12 V DC step down converter, and two Dewalt batteries.
One at 18 V 5 Ah, other 18-54 V 9 Ah.
I've connected pump to step down to battery correctly, but ...
- 23
4
votes
2
answers
945
views
Will a buck converter clean the power output from an automotive?
I want to permanently attach an ESP32 module and an LTE modem/hotspot to my car. I want to power these two devices using the car's cigarette lighter socket. The socket gives 12 VDC so I will be using ...
- 41
0
votes
0
answers
64
views
Buck Converter Output Voltage Swing problem
I am designing a voltage mode control buck converter and I have an issue with my output voltage swing. I made calculations for type 2 compansator. I can't figure the cause of problem is stability of ...
- 27
0
votes
2
answers
1k
views
Calculating inductor value for my buck converter [duplicate]
I'm trying to understand the SMPS operation.
The goal is to select inductor (L1) & capacitor (C1) values that satisfy the working condition below:
V1: 22-26 V range.
Power supply required: 1 A.
...
- 13
0
votes
0
answers
178
views
DC/DC split rail converter like TI's Fly-Buck™ coupled inductor topology but with a non-inverting buck converter
Introduction
First of all, I hope you can read this through. It's rather long!
I was trying to design a DC/DC converter for a Class-D amplifier that requires a 48V input and also an auxiliary 12V ...
- 33
0
votes
0
answers
38
views
Thermal analysis of a step down regulator
LTM8053 datasheet
I tried to plot the thermal graphic (watt-celcius) for this buck converter in MATLAB. The main goal is to find losses which turn into heat. Reasons for heat most of time switching ...
- 15
1
vote
0
answers
46
views
Are the prinicples the same for designing a high side vs low side buck?
I am an analog engineer that is getting into SMPS design.
This is a high side buck:
This is a low side buck:
simulate this circuit – Schematic created using CircuitLab
Assuming that I take ...
- 84.8k
0
votes
0
answers
140
views
What is the standard form for writing the second order transfer function for Input impedance?
When writing the transfer function for a system, the Characteristic equation in the denominator which carries information about the poles of the system is equated with the standard second order ...
- 31