Questions tagged [buck-boost]
A non-isolated DC-DC converter topology
234
questions
0
votes
0answers
27 views
Powering brushless motor only works with separated power supplies
I have recently taken over for a guy who retired from my company and I am working on getting a prototype that he designed back in 2016 up and running.
We are using two 3.6 V 18650 batteries to power ...
1
vote
1answer
86 views
What is the min and max input voltage range of a buck converter to maintain efficiency above 90%
I want to design a stepdown converter from 72V lithium ion battery to 12V, 5A. I am torn between using a flyback converter and a buck converter. Which topology will give me maximum efficiency at that ...
1
vote
1answer
43 views
Can I use common mode power line choke as 1:1 transformer in isolated buck-boost switched mode power supply at 20 - 100 kHz?
I'm planning to build a multi-output power supply that allows output voltages between 0 - 30 V and currents below 5 A. The idea is that I will purchase a number of 30V 5.3A power bricks (unknown if ...
0
votes
1answer
97 views
Can I drive LEDs directly with an LM2596 DC to DC converter? [duplicate]
I'm aware that LEDs need to have their current limited and cannot be connected directly to an unregulated power supply or they will 'blow'. However, can I use a LM2596 DC to DC converter to drive ...
0
votes
1answer
44 views
Splitting output power of a PFC stage to three flyback converters
I want to design three flyback converters whose input is taken from a single power factor correction circuit based on boost converter topology. The PFC stage delivers 200 W (400 V, 0.5 A), and I want ...
-1
votes
1answer
59 views
Why is the peak efficiency higher in Buck-Boost Controller when running below the AM band and lower above AM band?
I have seen this part LT8253/LT8253A, and it says in the datasheet that "The LT8253 can deliver up to 100W output power with 98% peak efficiency when running below the AM band.
The LT8253A can ...
-1
votes
2answers
75 views
Buck/boost converter (XL6019) produces wrong output voltage when powerbank goes less than 5v
I recently bought a buck/boost converter (XL6019), and I was trying to boost to 9 V to power a device (RC Car).
My idea was to use a power bank instead of 6 x 1.5 V AA batteries, but I realized that ...
0
votes
1answer
48 views
Providing precise 12Vdc and 5A (approx) in a vehicle [closed]
I need to have a relatively high amp (5A or close) source in a vehicle, as clean as possible, at a constant 12Vdc without big bumps or fluctuations. I know the regulator does the job by default, but ...
1
vote
1answer
45 views
Inverting Buck-Boost DC-DC Converter output and input ripple
I've designed and built an inverting buck-boost converter, but there is a persistent ripple that occurs on both the input and output voltage waveforms, regardless of input and output capacitor sizing. ...
2
votes
1answer
74 views
What is causing this drain current ringing
This is 4 kW Buck boost, Vin Min = 200 V. L = 600uH, switch used is C3M0065100K. With just 2.4 kW power, I notice the high Di/Dt on bottom switch drain current. Top and bottom switches have RCD ...
1
vote
1answer
98 views
Why the TPS6104 can't output 27V voltage?
I bought a demo board of +- 12V voltage：
here is the schematic I drawed by the board:
I changed the 220k R1 to 500k potentiometer.
By the formula that gived in datasheet:
I expeted 27V voltage: , ...
2
votes
1answer
58 views
Ultra low ESL capacitor for boost converter
I am designing DC-DC boost converter and I found out that capacitors generate huge voltage spikes on output because of their inductances. Even so called "low ESL" capacitors (10-12 nH) are ...
0
votes
1answer
90 views
In DC-DC converters, how can the ripple current affect the circuit's performance?
I have a DC-DC buck boost converter (TPS55288) that I was planning on using for a project. I'm making a revision to my current heated gloves, and my circuit needs to be as small as possible since the ...
3
votes
3answers
565 views
Why is the current linear in a boost converter? Why doesn't the capacitor make it sinusoidal?
I understand that the voltage across the inductor is constant so the current will be linear, but what about the capacitor in the circuit(Sw off state)? Will it not affect the current waveform? I think ...
0
votes
0answers
37 views
LTC3115 component selection for schematic
For my project I am using the LTC3115 Buck-Boost converter (datasheet) that should provide an output voltage of 8 V and 700 mA with a switching frequency of 2 MHz. The input voltage range is 3.2 V to ...
0
votes
0answers
35 views
Hybrid charger and NVDC charger
I have some questions about the battery chargers.
Here are my questions,
1.) Could someone explain the Narrow Voltage DC charger, I try to google it, but I am still very confused.
2.) In what ...
0
votes
3answers
110 views
Current Sharing Circuit
I want to use this TI document to do the current sharing, about this document I have some questions I cannot get it. Could someone give some advice?
I do not understand how this circuit works and why ...
0
votes
0answers
57 views
Buck-Boost IC LM5118
I read the TI Buck-Boost IC LM5118, this is a Wide Voltage Range Buck-Boost Controller, but I am confused about something.
Do you know how to calculate the current stress on D1, D2, Q1, Q2?because ...
0
votes
0answers
74 views
Push Pull Boost Converter
I made a Push-Pull Buck Converter with Vin 350V and Vout 12V. I am currently trying to make it bidirectional by modifying the circuit, but the output makes no sense.
My schematic:
The simulation ...
0
votes
1answer
76 views
How does a boost converter behave when used as a battery charger?
I'd like to use a boost converter as the primary power supply for a lipo charger. Disregarding the BMS, which will be a separate component, how does a step-up boost converter behave when used as a ...
0
votes
1answer
69 views
How to use a battery charger evaluation module as a booster?
I have a power source that can give me around 0.9 ~ 1 V and 900uA. I would like to use the BQ25570 battery charger evaluation module to give an output of 1.8 V. I would like to attach a capacitor to ...
0
votes
1answer
70 views
DC -DC buck converter W/o PWM signal( kind of)
Hey so i'm new to electronics and I've tried constructing a buck converter (using software only) circuit without the use of an external PWM source (microcontroller, 555 circuit) and i came up with ...
1
vote
0answers
61 views
Lm311 as open loop controller for boost converter
Recently I’ve wanted to make a boost converter. To keep the output voltage stable when a load is connected there need to be a feedback from the output. The circuit above claim that it will keep the ...
0
votes
0answers
112 views
Basic ideas behind design of different topologies of DC-DC converter
I can analyse most of the DC-DC converter circuits that are mostly given in textbooks.
But how these complex topologies are designed for the first time i.e. what are the basic ideas that lead to ...
0
votes
0answers
55 views
Analog LTC3106 issue
I'm trying to use LTC3106 to provide 3.3V for my SAMD21. The goal is to use the sun when it is available (and recharge the battery with the excess) and use the battery when there is no sun.
Here is my ...
0
votes
0answers
38 views
Battery for GPRS module and voltage regulation
I work on a wearable GSM device powered with a LiPo battery.
I want to use a switching charger with a power path. My GSM module can consume up to 2 amps during data transmission and its working ...
1
vote
1answer
50 views
Buck- Boost converter failed on surge at 500volts
Basic Technical Details
The driver is basically a DC solar charge controller, it's used in solar street lights, it requires a battery and panel. This driver uses the Buck-Boost Topology. At night it ...
2
votes
2answers
473 views
What will happen if the input voltage of the buck-boost converter goes below the recommended input?
I am doing a solar panel project, but I don't have much knowledge about electronics.
I am planning to use a buck-boost converter that gives me a stable output (12V.)
What happens when the input ...
0
votes
0answers
55 views
Charging lead-acid batteries via a boost converter. Are my calculations right?
I want to charge my two lead-acid batteries connected in series to a stair-case lift. I do not have a proper charger (don't have ebay/amazon here) but I do have a 19V, 3A laptop charger (SMPS). I also ...
0
votes
2answers
46 views
Problems with LiPo Volt buck boost for a LED
I need a little bit of help in understanding buck-boost converter.
I have 4 LiPo 18650 batteries in series an BMS to charge and discharge the batteries properly.
After that I added the buck-boost ...
1
vote
2answers
117 views
How to improve buck converter's efficiency
I am designing a buck converter for 600 - 10V converting (60 times lower than input).
My first question - is this even possible? I've seen a 650 - 40V converter on mouser, but that is the best that I ...
0
votes
3answers
92 views
Soft latch switch circuit with buck converter load does not work
I have been experimenting with soft latch switches. There is one that EEV Blog has developed that only uses 2 NPN transistors and a P-Channel MOSFET. The circuit is seen at 14:44 in this video.
I have ...
0
votes
1answer
42 views
Can this Noise Suppression Filter/ RF Inductor be used in buck/boost converter instead?
Say I have a buck/boost converter operating at 100Mhz. Would this inductor (VAF201610FA-841-1) be a good choice if I needed larger inductance, over other fixed inductors? (considering I do not surpass ...
0
votes
1answer
89 views
the sound from the coil when the current is drawn
I have buck-boost converter using a TPS630250(4.2 ->Vin) - (3.3 -> Vout) in my PCB. This buck-boost converter can draw max 4A in buck mode and max 2A in boost mode.
While there is no load or ...
0
votes
3answers
77 views
Design own Buck-Boost converter - Some questions
For a project of mine I would like to design my own buck-boost converter because the fixed solutions are more expensive and a bit to big for my preferences.
Vin is 12VDC - 24VDC regulated to 12VDC ...
0
votes
0answers
41 views
LTC3115 Buck-Boost Converter isn`t able to provide specified current
Currently I am designing a regulator circuit based on an LTC3115-1 Buck-Boost regulator which should be able to supply a current of 1.5 A for charging a NiMH battery pack with 18 cells (18...28 V).
As ...
2
votes
1answer
70 views
Buck-Boost small signal
I read the paper "Simplified Analysis of PWM Converters Using The Model of The PWM
Switch", and I have some questions about the model of DCM (Discontinuous Conduction Mode) flyback.
This is ...
0
votes
0answers
46 views
Power output from a buck boost circuit is too low
Thanks to all who helped on the earlier part of the circuit - that's now fixed and working.
Now the buck boost circuit to drive the LED is working, but it only puts out a very small fraction of the ...
0
votes
2answers
40 views
Best practice to get several voltages from a wall adapter via buck/boost adapters
There are two battery operated devices connected to the garage door in my house. One is a bought solution which opens/closes the garage door, the other is a self-made module which detects whether or ...
0
votes
0answers
51 views
High efficiency buck-boost converters for 3.3V and 4V power rails up to 3A peak current
I need a buck-boost converter to power a 3.8-4.5V GSM module and a 3.3V controller from batteries. So I need a boost-buck converter that can give me a stable voltage over the lifetime of the batteries....
1
vote
2answers
366 views
Why is the Irms so different from Isat in different power inductors?
I'm looking at power inductors for a DC-DC boost converter clocked in the 500KHz range (but KHz could change if necessary). Here are two examples:
Example 1: Irms=55A, Isat=140A, 70nH
Example 2: ...
1
vote
1answer
94 views
Why do DC/DC switching controllers seem to favour the buck-boost topology over similar ones like Cuk, SEPIC and Zeta?
I am looking at various DC/DC converter topologies for a power system I am designing. The most suitable topology for me is one that can perform both step-up and step-down functions, so I am looking ...
0
votes
0answers
22 views
LTC3106 solar harvester over-voltage at output during recharge
I'm using an LTC3106 in the configuration of the attached schematic:
It works fine from battery and from Vin inputs, delivering the expected 3,3 V at Vout.
Problems arise when, with Vin present, the ...
2
votes
1answer
43 views
Reversible 4-switch buck-boost?
Can a 4-switch buck-boost be reversible?
The base scheme seems symmetrical but I did not find any reversible design.
Do you have an exemple of such a design?
0
votes
1answer
38 views
Transistors choice for buck boost converter using LM34936
I've been using TI's Webench online design tool for buck boost design purposes that uses LM34936.
The simplified schematic in LM324936's datasheet looks:
Webench design tool generated 4 different MOS ...
1
vote
1answer
219 views
How to bypass current sensor (ACS712) default 2.5V voltage output in buck/boost converter PCB
I'm having a bit of trouble coming up with the most practical fix for my buck/boost converter PCB. To give a bit of an overview, I'm using a current sensor to read the current value through an ...
0
votes
0answers
67 views
TPS61097A-33 booster providing lower voltage than input
I ve been trying to get the TPS61097A-33 working to get the promised 3.3V output voltage. I am using two AAA batteries as input and the circuit current draw is 20mA. I am using 4.7uH inductor and 10uF ...
1
vote
0answers
66 views
How does this compensation network work?
By accident I stumbled upon this Linear Technology application note (LT1074/LT1076 Design Manual):
https://www.analog.com/media/en/technical-documentation/application-notes/an44fa.pdf
Just for fun I ...
0
votes
1answer
122 views
1200w dc-dc boost converter low voltage protection not working
I've purchased a 1200w dc-dc converter with the model number SZ-BT07CCCV.
I'm using it to convert 12v from a big battery to 24V.
the converter comes with three potentiometers according to the ...
1
vote
0answers
35 views
Rule of thumb for boost converter current usage
I have a sensor that requires 12V DC for 14 seconds. I only have a 6V source. The device pulls 6.2mA at 12V during the 14 seconds. If I use a boost converter to get to 12V should I assume >12.4mA ...
