The MCP4261 become hot after used half hour, what's wrong?

[laoadam]

I am using MCP4261 controlled by MEGA2560, it work well, and meet my need by the sketch, the first one burnt some time, and the second one I count the time become hot just half hour after power on.

 

[Diver300]

I think that a bit more information is needed here.
Is J1 the MCP4261 ?
The pinout shown for J1 does not match the pinout for the MCP4261. but if you are connecting the pins as numbered to the MCP4261, that should be OK.
What is the MCP4261 being used for?

 

[ronsimpson]

MCP4261

Information is critical;
The part is a dual "POT".

Are you certain the supplies are connected right?

it work well

I think this said; You can move the POT brom the MEGA2560?

 

[laoadam]

Thanks for reply.
I reattached the drawing.
The circuit reference to: https://arduinotehniq.blogspot.com/2016/07/mcp4261-dual-digital-potentiometer.html

 

[Pommie]

What is the MCP being used for?
How hot does it get?
What resistance is it?
Is the MEGA running at 5V?

Mike.

 

[alec_t]

What loads do you have attached to pins 6 and 9?

 

[laoadam]

What is the MCP being used for?
How hot does it get?
What resistance is it?
Is the MEGA running at 5V?

Mike.

Thank you Mike,
How hot does it get?
burnt the breadboard.

What is the MCP being used for?
The MCP used to get analog voltage to control LED.

What resistance is it?
The DAC is 10K,

Is the MEGA running at 5V?
Yes.

 

[laoadam]

What loads do you have attached to pins 6 and 9?

Thank you.

The load are two LED.

 

[ronsimpson]

The load are two LED.

So you might be using the lowest resistance. 5k ??
---edited----
Data sheet: Max current in POT is 2.5mA. How much current in your LED. Not what the LED is rated for but what is the real current.

 

[Pommie]

To get your LEDs to light the resistance will have to be very low. If you write 1 to the resistance value then it will be 40Ω and a current of 3/40 = 75mA will flow. This will destroy your LED(s)- assuming normal 20mA ones. A setting of 4 will reduce the current to less than 20mA and your LED(s) will survive. However, the chip will be dissipating 1/4W - assuming both resistors used. And, that is why it's getting hot. You cannot drive LEDs directly from these devices.

Mike.

 

[alec_t]

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