To test I plug in a 12v source and try by plugging a multimeter on the output and turning on the blue trim potentiometer it's fix at 12v however I turn it up or down what could be wrong ?
Attached Files
-
-
Re: brand new buck converter does not step up or down
Are you sure that you are turning the pot control for the voltage because one is voltage and the or one is current -
Re: brand new buck converter does not step up or down
You don't have a load, so it likely just charged the output cap to the highest voltage.Comment
-
Re: brand new buck converter does not step up or down
Probably for best results because this is a buck converter not a boost converter which as adjustable the voltage control your voltage would go beyond the input voltage but on a buck converter it is the opposite in that you have to have some load on it for the voltage control to work but the current control also affects the voltage outputLast edited by sam_sam_sam; 08-30-2022, 07:54 PM.Comment
-
Re: brand new buck converter does not step up or down
please look at this from minit 12 https://www.youtube.com/watch?v=9--_jaxiXhE&t=16sComment
-
Re: brand new buck converter does not step up or down
What happens when you put a load on the output dose it charge at allComment
-
Re: brand new buck converter does not step up or down
no, because the output cap holds a charge, and the charge is going into the chips feedback pin.
unless your output cap(s) have a discharge resistor you never power up without a loadComment
-
The MT3608 is a constant frequency, 6-pin SOT23 current mode step-up converter intended for small, low power applications. The MT3608 switches at 1.2MHz and allows the use of tiny, low cost capacitors and inductors 2mm or less in height.
Internal soft-start results in small inrush current and extends battery life.
The MT3608 features automatic shifting to pulse frequency modulation mode at light loads. The MT3608 includes under-voltage lockout, current limiting, and thermal overload protection to prevent damage in the event of an output overload. The MT3608 is available...10-07-2024, 05:02 AM -
Hi folks.
Any help with identifying this IC? Should be some DC/DC step down converter. 'ACF G45' ... I thought, it is Monolithic Power Systems ( based on this topic --> https://www.badcaps.net/forum/troubl...and-datasheets ), but can't find this marking there. Will be thankful for any hint. Thanks in advance.... -
Hi,
my Lenovo 720 is dead. :-(
I guess i have found an issue on the 5V buck converter (**BAC7NH** from Silergy (also called SY8288C 5V)) but i am not completely sure so i want to ask here for some hints.
Here is a Schematic of the IC: https://prom.ua/p1498216381-sy8288c-...ac-bacxxx.html
When i attach the supply 19V, i only have 1.8V on the OUT (it should be 5V). The IC is getting hot.
The EN1 is completely off 0V, EN2 show 1.5V.
If i inject 5V on the EN1 the OUT goes up to 2.6V (but never reach 5V).
BS seams SHORT to the OUT.... -
Hello everybody,
I need to replace a shorted SOT23-5 step down converter in a consumer audio device marking E16q9. What I found out from the board layout and measurements:
Vin: 5,0V
Vout: 3,3V (connecting to all 3V3 inputs of a N32905U3DN)
Pin1: ? (perhaps enable)
Pin2: GND
Pin3: Vout - connected to 3µ3 coil
Pin4: Vin
Pin5: Feedback, voltage divider, two resistors connect Vout-Pin5-GND, 680k+133k
I searched many datasheets, but no one seemed to match according the surrounding components.
Best similar parts I found were... -
Dear members,
Let us consider the buck-converter circuit of +1.05VS_VCCPP in the PDF. +1.05VS_VCCPP is a 1.05v voltage rail. The schematic says the circuit can provide up to 20A of current. It belongs to a laptop: Lenovo G470. B+ is 19v.
Now assume we connect +1.05VS_VCCPP to many ICs to provide power for them. The laptop works in a way that mostly less than 20A are drawn from +1.05VS_VCCPP but sometimes the required current exceeds 20A. For example, 25A or 30A.
PU702 is the controller IC in the buck-converter circuit. It controls the output voltage according to the feedback...
Comment