how the actual chip power more than simulation results.

[wangkes9]

The Vcc source 5mA current when I do simulation.

But when I do real test using the chip, Vcc source 18 mA current.

Why, is there latch up effects?

But the analog chip work well and I design it according to the design rule!

 

[electronrancher]

Any way to turn on/off functions in order to find the supply current of each block? it sounds like there is a layout mistake somewhere - if you use diffusion resistors I would look out for an incorrect tub tie.

Is the current always 18mA, or is it dependent on VDD? Does the IDD start to rise linearly, or does it jump up sharply when you pass 3v, 4v? All of these clues will help you determine where the mistake is.

 

[JoannesPaulus]

electronrancher has very good ponts, I would add that if the chip includes a lot of digital switching, your estimates might be a little off. If you are designing in 65nm or less it might also be leakage current (but not 13mA, hopefully!) in the logic gates especially if you use low VT.