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Questions tagged [led-driver]

An LED driver is a self-contained power supply that controls the amount of current and voltage supplied to an LED light. An LED constant current driver monitors the loop current of each LED and automatically adjusts the generated DC voltage output to the minimum value needed to produce the highest forward voltage. As mains power is AC and Light Emitting Diodes run on DC, this current needs to be converted by a rectifier

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Why is Duty cycle for CC LED driver voltage specific, when Output voltage has a compliant range?

Commercial CC drivers usually mention "x-yV output" range which means that the output voltage has a compliance range where CC operation will be maintained in constant current mode. But then ...
roaibrain's user avatar
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Can one CC boost LED driver be used for 2 different loads separately?

I have a constant current boost LED controller (TPS92691) which I am designing to output 4A switching between two LED strings. This is with a 2S lipo battery. One string has a stack forward voltage of ...
roaibrain's user avatar
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2 answers
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Does a current sense resistor not always mean a constant current output for dc-dc converter?

I've had a understanding that having a current sense resistor feeding into sense pins or a feedback pin meant that the inductor current was changing wrt the variations across sense resistor, hence ...
roaibrain's user avatar
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Apart from MOSFET selection what else determines max output current for LED controller IC?

TPS92691 is a LED controller, not a monolithic IC which has an integrated FET. Hence, I'm curious why the landing page for this part (https://www.ti.com/product/TPS92691) mentions that Iout(max) is 5A ...
roaibrain's user avatar
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Constant current driver issue or misunderstanding

I want to learn how to use a constant current driver. After some research I ordered an NSI45030AT1G driver which delivers 30mA from 10V to 40V according to the datasheet. After a real testing, I am ...
SkePsis's user avatar
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Feedback compensation on a buck-boost led driver

I tried to calculate the compensation network for a TPS92692 in buck-boost topology and I can't find the same value for the typical buck-boost led driver (page 41 of datasheet). Section 9.2.2.2.12 ...
msch's user avatar
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6 votes
2 answers
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Is an LED driver IC just a boost conv with voltage across Rsense fed into FB?

There's these really cool things called power modules, but they are all marketed as normal dc-dc converters. Not many as "led drivers" for currents more than 1 A. The basis behind this ...
roaibrain's user avatar
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3 votes
1 answer
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Troubleshooting a HT16K33 + 14 segment LED showing segments when not addressed

I'm working with a board that has multiple 14 & 7 segment displays all being addressed using an HT16K33 where various segments are either not displaying or are being lit when they shouldn't. In ...
nageeb's user avatar
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1 vote
1 answer
62 views

PI filter for two buck drivers for a low-emi solution

I'd like to save space on a circuit that uses two buck LED drivers. The circuit is designed for a low EMI solution and there are two separate PI filters on each Vin pin (recommanded on the datasheet). ...
msch's user avatar
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1 vote
3 answers
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Purpose of electronic elements in a capacitive dropper circuit

I have found a capacitive dropper circuit in an LED light bulb: I have a few questions about this circuit: Normally, in capacitive dropper circuits, I would expect a resistor parallel to C1. I am ...
MasterMind's user avatar
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139 views

How to make smooth LED brightness control without PWM?

I want to make a very smooth adjustment of the brightness of a single 350 mA 2.85 V LED without PWM. And I need to get low brightness values. I do not know how to control the LED properly. Constant ...
Andre's user avatar
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LM393 Window Comparator driving LED using 2N2222

I have a circuit im trying to design utilizing the LM393 as a window comparator. I have them in wired or (outputs tied together) but im strugging in figuring out where I need resistors. Looking at the ...
user3182474's user avatar
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1 answer
31 views

Can single digit 7-segment displays use free digits from a multi-digit multiplexer?

The title's a bit convaluted, so I'll ellaborate. I'm driving a 4-digit 7-segment display with a multiplexing controller, the kind where it sets one display at a time and relies on persistence of ...
Steam Ranger's user avatar
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2 answers
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Between direct FET, boost, and stacked LDOs with current sink, what's the best way to switch b/w 2 high power loads?

I have a 2 strips of 3 high powered LEDs as the loads. The load is hooked up as : Config 1 Strip 1 : 3 Green LEDs (3.3Vf, 4A) in series => 4A and 13.2V load Strip 2 : 3 Red LEDs (2.8Vf, 4A) in s in ...
roaibrain's user avatar
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-2 votes
1 answer
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Could someone point me to a textbook or theory behind the workings of LED driver circuits with automatic voltage regulation [closed]

In a video on YouTube I saw a simple LED driver circuit. This circuit is quite different from the circuits that I have learned during my studies like boost converter, buck converter, buckboost ...
MasterMind's user avatar
3 votes
2 answers
71 views

Current peak on a low EMI buck LED driver

I'm designing a buck LED driver using the LT8376 and I'm following the typical application for a low EMI solution (page 26). On the output, the schematic proposes a 100 nF capacitor in parallel with ...
msch's user avatar
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1 answer
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LED strip light won't work... sorta

Making a lamp using a DPDT SPDT ON-OFF-ON toggle. ON1 is the lamp. No issues there. ON2 is going to be an LED strip in the base to function as a nightlight. The single-color LED strip is what's ...
Dascalargo's user avatar
1 vote
2 answers
80 views

Identify LED driver IC MRVL

I need help identifying that IC used in the LED driver. MRVL 8183B0 324AFTG
Berk 's user avatar
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0 answers
59 views

Why does my monitor back side become energized after CCFL to LED repair?

I am repairing my old monitor Samsung syncmaster 740b from not working CCFL lamps to LED lights with a led driver. I just had a first test. I have got electricity hit, investigation shown my metal ...
Gleichmut's user avatar
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1 vote
1 answer
60 views

RGB LEDs indvidual brightness control [closed]

i want to make RGB LEDs panel using https://www.lcsc.com/product-detail/Light-Emitting-Diodes-LED_TCWIN-TC5050RGBF08-3CJH-P35C_C784539.html RGB LEDs. I will put 100 LEDs in tha panel and want to ...
Zunuran Nasrullah's user avatar
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0 answers
54 views

Choosing between single or dual buck LED driver ICs for LED driving

I'm at a crossroads in designing an LED driving circuit and could use some insights. My setup involves driving LEDs in constant current mode, and I'm considering using a buck driver IC for this ...
msch's user avatar
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0 votes
4 answers
183 views

LED premature failure

I am using a blue LED from Rohm in our design. I have gotten some suggestions from other sites, but I wanted to give you all a chance to take a look at the design. We have been having premature LED ...
justin1269's user avatar
1 vote
3 answers
79 views

Drive the current control pin with a voltage

I am aiming to use the TPS929160-Q1 LED Driver for a project. Basically I need to drive LEDs with PWM signal from a MCU (which this component can do very well) but the project also requires to be able ...
Nucrino's user avatar
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1 vote
3 answers
253 views

LED in op-amp`s feedback loop shines dimly. How to eliminate this?

I am working on my project's visual indicator part. Everything woks as expected, but LED shines dimly when connected in feedback loop and with no control signal. Shining is barely visible, but it is ...
Manac's user avatar
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2 votes
2 answers
306 views

LM3914 Bar/Dot display driver

I would like to try out the LM3914, but I could use some help in understanding how to calculate the current limiting resistor. I am referring to page 9 of the datasheet: Do I need to modify the ...
Status Re's user avatar
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0 answers
23 views

Can I use BP2857 constant current LED driver IC with a PWM-controlled MOSFET for dimming and turning the lights on or off with an ESP8266/Arduino?

I am trying to build a remotely controllable aquarium LED light. I live in a country where DigiKey and Mouser are not a thing. Electronic components are hard or impossible to find in this country. So ...
ISHRAQ's user avatar
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1 vote
1 answer
115 views

LED passes the current through itself but doesn’t turn on

I have ten LEDs connected in series that all have the same characteristics. When I slowly raise the voltage, nine of them turn on but one of them in the middle of the circuit stays off. The LED which ...
wolyure's user avatar
  • 149
5 votes
2 answers
638 views

RGB digital to analog converter

I am seeking help to design a small PCB that can translate digital RGB like Neopixel to analog signals for driving high current LED RGB. I know it's a bit weird. I would like to connect to a board ...
Jesper Egsgaard Nielsen's user avatar
2 votes
1 answer
90 views

Can I power LEDs of different forward voltages connected in parallel with a single constant current source?

I am a complete beginner at designing circuits. I was thinking of building an aquarium light. As plants need a full spectrum of light to grow properly, this is the selection of colours I came up with ...
ISHRAQ's user avatar
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1 vote
1 answer
62 views

Trying to overdrive LEDs my power supply amperage mysteriously "backs off"

I have a 48 parallel matrix of 3v LEDs. I'm trying to overdrive it. I set my supply to 3v and 0.5amps and the display glows. Up the amperage to say 1amp it gets brighter. So far so good. I keep ...
jackisquizzical's user avatar
0 votes
2 answers
173 views

MOSFET not fully turning off

This is the circuit I'm using to control a white LED with the MOSFET's gate connected to an output pin on the STM32: This is the 5V power source: VIN is a single cell li-ion battery. The enable pin ...
donut's user avatar
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4 votes
2 answers
744 views

Please offer comments, critique on self-resonating invented buck joule thief converter for third world use [closed]

Even though I'm not an EE, I have simulated the Joule Thief to death in LTSpice, but I have not yet made a prototype of this circuit. I have a friend who is an EE who won a contract to light some ...
MicroservicesOnDDD's user avatar
2 votes
3 answers
1k views

Need to drive several 5 V LEDs from 3.3 V logic

I have done similar level shifting several times using discrete components. This time, due to a need of driving some number of 5 V LEDs from a 3.3 V microcontroller, I prefer to use some level shifter ...
Sener's user avatar
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0 votes
1 answer
52 views

Output voltage not changing with a constant current driver

If I attach a voltmeter to the output of this constant current driver and lower or raise the input voltage (100-230V,) the output voltage remains constant at 56V. Should it not fluctuate between 40-...
Guit4eva's user avatar
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1 vote
0 answers
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Driving bidirectional LED Christmas lights

So I bought a set of 500 lights from Temu and noted that they work at 24 V, with half of them lighting up at one direction of current and the other half when the direction is different. There’s only 2 ...
Joonas Joensuu's user avatar
1 vote
2 answers
257 views

How can I modify this cheap power supply for constant current output?

I bought a 12V, 2A PSU for 1$ and it has the common design with CSC7203 IC: The one I got didn't have the input fuse, capacitor, TVS diode and the output filter inductor. I added all those myself. ...
ElectronSurf's user avatar
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2 votes
1 answer
167 views

LED driver identification needed

Can someone identify IC "U1" in the below LED lamp PCB? I've tried to google the identifiers but didn't find anything :-( It's an 18 W lamp for 240 V AC, and according to the customer it's ...
mic's user avatar
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1 vote
2 answers
141 views

LED controller voltage reduction

I have a 12v 4A LED controller and I plan to use it with these 3.4v 350mA RGB LEDs I want to reduce LED's brightness permanently. To do this I need to limit controller's Vout from 0V-12v to some lower ...
Oleksandr's user avatar
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1 vote
1 answer
120 views

Identification of an 8-pin IC marked YS17 RBSCK0 2022QED

Please help me identify an 8-pin IC marked ( YS17 RBSCK0 2022QED ), i have a LED circuit in which this IC is burned out. Can anyone tell me the alternative of this IC. I searched the net but I couldn'...
Mak's user avatar
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0 votes
2 answers
67 views

Can I use LEDs in parallel with an LED driver?

I'm using an LED driver to drive a few LEDs in parallel but I'm confused by the datasheet. The component is a PAM2863. In the description, you can read "designed for driving single or multiple ...
Gabriel Corrales's user avatar
1 vote
1 answer
92 views

Power Raspberry Pi Pico from Mains (use LED driver?)

I'd like to permanently install a Raspberry Pi Pico in a place in my house where I don't have a power socket but a power line (230V, 50Hz). As I understand it, there are two ways to power the Pico: ...
Johannes Bauer's user avatar
0 votes
1 answer
76 views

WS2812 vs TLC5947

I want to know why one would use the TLC5947 constant current driver over a WS2812. What are the benefits of the TLC5947? Do you have more control since you can set the max current of an LED?
fiven80440's user avatar
0 votes
2 answers
85 views

Will boost converter spike kill LED?

So I am attempting to design an LED driver that takes 7.2V and converts it to 36V at 2.4A. For this task I am utilising a boost converter but the problem I am seeing is that the model shows a initial ...
leasthollow's user avatar
3 votes
1 answer
115 views

Transistor choice for common anode 4x4x4 LED cube?

I'm working on a very basic 4x4x4 LED cube. The LEDs are single color LEDs (blue, in my case) with a max forward voltage of 3.2v. I understand (conceptually) everything about how the cube functions ...
n0ah's user avatar
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0 votes
1 answer
88 views

Swapping Fairy Lights Power supply/driver [closed]

Hi I have some fairy lights which work just fine. My only issue is they don't remember what pattern I set them to after turning them off so they always turn on in the demo mode. I've been looking at ...
rohtua's user avatar
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0 votes
2 answers
97 views

Confused about how to wire headphone jack with a schematic

I've been trying to make an LED driver that responds to a signal sent over an audio cable and found this schematic: I'm pretty sure that the middle ring on the jack and socket (third contact) is the ...
captainretro's user avatar
0 votes
1 answer
59 views

Non-inverting driver for LED

I am looking for a non-inverting LED driver. The main idea is to connect 20 x LEDs (4 series of 5 LEDs each) to 12V source (car battery: car is running so there will be some interferences -> I use ...
SkePsis's user avatar
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0 answers
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Two wheeler LED turn indicator design calculations clarifications

This is a continuation of this question. I have couple of questions. In the application example the clock frequency is 763 Hz. May I know this 763 Hz is derived from LED blinking frequency of 1.49 Hz?...
Confused's user avatar
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1 vote
2 answers
100 views

How do I run four 1 watt 3.4 volt LEDs with a 5 volt 2 ampere power supply without overheating?

I am trying to run four small, 1 watt LEDs with the help of a charger that supplies 5 volts at 2 amperes current. The LEDs require 3.4 volts to run. How do I run them without the LEDs overheating? I ...
UjanRoy's user avatar
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2 votes
1 answer
110 views

MAX7221 with multiple LEDs per point

I am using a MAX7219/MAX7221 chip in a keyboard design in order to light up the individual keys. The keyboard is going to have exactly 64 keys so with the 8x8 matrix the chip handles I will be able to ...
SukkoPera's user avatar
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