Questions tagged [buck-boost]

A non-isolated DC-DC converter topology

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Buck converter exam question [closed]

Is my solution to the problem correct? Also this was asked in a internship exam and we had no buck converter in our syllabus. So can this problem be solved intuitively without knowing anything about ...
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Issue from my buck/boost converter

After my simulation, I am getting this in my output, which does not look good at all. I find it difficult to find a spice model for DC/DC isolator that can give me a positive, negative supply, and ...
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Boost battery voltage without regulating it

I'd like to boost the voltage of a lithium battery while having the converted voltage reflect the battery's state of charge (such that the output voltage equals the input voltage plus a set amount). ...
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How is the circuit behaving during positive and negative half cycles?

Took this from a IEEE paper. I am confused with converter configuration. During the positive half cycle of supply, wouldn't the diode D1 be forward biased and D2 be reverse biased? IEEE PAPER
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protect from in rush current of buck convertor

I made a PCB base on the following schematic, it uses a buck convertor for 12 to 5 v and then uses an LDO for 5 to 3.3 to run my ESP module I use 2 P-channel MOSFET for polarity protection , but ...
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Buck-boost converter (LTC3442) not producing output until excited

EDIT: Added datasheet for the inductor and some oscilloscope measurements. I'm using a LTC3442 buck-boost converter from Linear Technology / Analog Devices (datasheet) in my design to produce a 3.3V ...
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Why is buck-boost converter showing a different trend than buck and boost in efficiency peaking point?

In general I was under the impression, the efficiency is highest when input and output voltage are close to each other. This holds good for boost (text book image below) and buck (personal experience)....
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Charging a battery with a lower voltage battery

Is it possible to charge a 44.4 V LiPo battery with a lower voltage LiFePO using a boost converter and some form of overcharge protection? I have a battery powered plane using a 12s lithium polymer ...
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3 answers
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LED driver 3.5V 25A. Low voltage, high current

I need to make a driver for an LED that works at 3.5 V 25 A. My idea was to make a DC/DC regulator from 12 V to 3.5 V and then a current limiter, but I'm at a loss as to which IC to use or how to ...
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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 ...
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What is the min and max input voltage range of a buck converter to maintain efficiency above 90% [closed]

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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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. ...
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2 votes
1 answer
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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 ...
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1 vote
1 answer
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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: , ...
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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 ...
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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 ...
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3 votes
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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1 answer
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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 ...
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2 answers
746 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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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....
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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: ...
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