All Questions
Tagged with buck led-driver
33
questions
6
votes
3
answers
937
views
Reduce output current ripple on hysteretic buck converters
I am learning to use a new type of regulator: a buck with hysteretic control, therefore with no fixed frequency and no output capacitor.
As example, I was trying out the ILD4001 for an LED driver. ...
- 1,305
5
votes
2
answers
492
views
Open-loop Buck LED dimming
About this buck LED driver...
TL/DR the questions:
1) I intend to drive the FET from a microcontroller PWM via a suitable FET driver. This open loop control scheme seems too simple. Is it a trap? I ...
- 79.5k
5
votes
1
answer
690
views
36x LED 5730 in series: diodes burnt when LED driver (based on BP9833A or MT7854BD) powered up
Background:
I have 18W, 36 LED lamp fixture which I cannot change.
Originally it has 2x parallel 18off 5730 LEDs and 300mA driver. It works for some time, but diodes starts burning. I thought that ...
- 61
4
votes
4
answers
514
views
Multiple switching LED drivers on single PCB
I am working on a high power LED board project. It requires to have 100 LEDs, of different types and colors. There will need to be 17 individual strands (need to be able to dim them separate.) Max ...
- 736
4
votes
2
answers
764
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 ...
- 2,892
4
votes
2
answers
824
views
Can overshoot current from DC/DC converter damage LED lamp?
I'm building buck converter to drive led lamps. It consists of microcontroller, PWM generator, buck-circuit and current sensor. Microcontroller knows what target current should be and sets duty cycle ...
- 395
3
votes
2
answers
80
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 ...
- 83
3
votes
3
answers
425
views
Setting current on Diodes Inc PAM2863 LED driver IC, with external resistor AND driving different voltage to VSET
I'm looking to use the Diodes Inc PAM2863 DC-DC LED driver in a project.
The datasheet gives a V=IR method for setting the average output current with an external resistor, where Iout = 0.1 / Rs.
...
- 31
2
votes
2
answers
1k
views
Why is the efficiency of this LED driver circuit so low?
I created an LED driver board based on PAM2863ECR http://www.diodes.com/_files/datasheets/PAM2863.pdf
The board includes three identical driver circuits to drive three LEDs. I'm not able to wire the ...
- 2,177
1
vote
2
answers
76
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 ...
- 1,235
1
vote
1
answer
162
views
Buck controller MOSFET drive voltage
I am trying to design a switching regulator for LEDs, which uses the LM3405 as controller. This IC uses the BOOST pin to power the internal MOSFET driver, which controls an internal MOSFET. There are ...
- 1,305
1
vote
1
answer
1k
views
What is the difference between buck and step-down converter
I always thought "buck" and "step-down" are synonyms. But now I'm looking at two datasheets:
CAT4201
CAV4201
They seem very similar, but the first is described as "350 mA ...
- 1,235
1
vote
1
answer
71
views
TPS9264x Synchronous Buck Controllers for Precision Dimming LED Drivers
I have some questions about TI's TPS92641.
Please see below:
1.) Does anybody know the principle of Chopper OTA? there are no too much information in the datasheet.
2.) What's Quasi-hysteretic ...
- 413
1
vote
3
answers
350
views
LED buck driver
I'm trying to build a 1A LED buck
It works well, current in leds depends of pwm duty until 1A and more, but when I watch signals with an oscilloscope, there are noise or oscillations on Rsense.
See ...
- 71
1
vote
1
answer
67
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). ...
- 83