TMS320F28335: +1.9V power pins current requirement at max sysclkout 150MHz for the TMS320F28335 MPN

Sagar Dudhal said:

For the above image what will be total maximum currrent at 1.8V when my device is at 150MHz SYSCLKOUT.

First off, when your device is operating at 150 MHz, your operating voltage needs to be 1.9v, not 1.8v. From Table 7.5.1, it would be around 350mA. Fig 7-1 is the “typical” current. It is a good idea to have at least 30-40% margin in your PDN.

Sagar Dudhal said:

Also what is IDD currrent.

IDD is the current for the digital portion of the device (the “core”) i.e. the CPU and the peripherals.

Sagar Dudhal said:

please let me know does this 1.8V current and IDD current are separate current.

1.8v current includes IDD, IDDA18 & IDD2A18.

Sagar Dudhal said:

Also if i want to choose my 1.9V powersource for the microcontroller does it have addition of current highlighted in bluse boave 1.9V = IDD+IDDA18+1.8V current

Please see above.

Sagar Dudhal said:

Where its mentioned The blue triangle is the sum of IDD and IDDA18.

Those are the only rails in the device fed by 1.8v/1.9v.

Graph shows around 325mA. However, as mentioned in my first reply, you should use a number of 350mA with adequate margin. You don't want the supply voltages falling below the datasheet limits anytime.

Sagar Dudhal said:

Trying to figureout Where its mentioned The blue triangle (350mA line) is the sum of IDD and IDDA18.

Those are the only two entities that are fed off the 1.8v/1.9v rail.