DAC 0808 heating issue

[mrarslanahmed]

hi all i am working with dac 0808 i have implemented the circuit given in the datasheet (circuit schematics is attached)

i have changed the positive vref to +12v and vee to -12v and capacitor bypass to ground on positive vref ,rest circuit is same, the problem is after giving power to the system IC 0808 get heated , i cant figure out the problem please help me in this regards.

 

[GUMY]

Is something connected to digital inputs?

 

[mrarslanahmed]

yes i attached 3.3k resistor with 5v

but later when i disassembled circuit that time i did not attached any thing..

 

[mrarslanahmed]

i think floating terminal was the issue no there is no heating ... but the system is working in reverse logic for all 0's output of the dac is maximum and for all 1's output is minimum.. is this the way the should work

 

[schmitt trigger]

The DAC0808 is an old, old IC. Can you read the datecode on the package?
It may be, most likely, a surplus component, and if purchased on the gray market its health cannot be guaranteed.