i've developed a multi-dsp board and it is running fine.
The point is that the 1.8V transistor used for core voltage regulation, is getting quite hot.
I've used a SOT223 device for each DSP, it is running at half its maximum dissipation capability (about 0.7W over 1.6W maximum)
and its temperature is rising about 35°C over room temperature: it is within its specifications also for tbe highest working temperature expected.
Now i've to design a new PCB release and, instead of using a bigger DPAK bipolar, i was curious if
i could use a small SMPSU to generate a 1.8V core voltage separately to power all DSPs.
My question is mostly centered if i have to follow any power-up / power-down timing procedure for the 3.3V and 1.8V lines
(eg: on power up first apply 3.3V, then apply 1.8V, for power down take 1.8V off then 3.3V....or something).
Ok, quick "datasheet tour" and first question should be cleared:
1.Power on the IC and bring it out of reset.
The order of the power supplies (DVDD, IOVDD, and AVDD) does not matter
Other points? Let's cook these DSPs with a test?