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

Thread starter #1
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.
POST26.1.JPG
 

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Diver300

Well-Known Member
#2
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?
 

Pommie

Well-Known Member
Most Helpful Member
#5
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

Well-Known Member
Most Helpful Member
#6
What loads do you have attached to pins 6 and 9?
 
Thread starter #7
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.
 

ronsimpson

Well-Known Member
Most Helpful Member
#9
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.
 
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Pommie

Well-Known Member
Most Helpful Member
#10
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

Well-Known Member
Most Helpful Member
#11
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