Problem about core current for BF561

Hi,

As you said you are operating at VDDINT = 1.2V. What is the frequency of operation.(CCLK/SCLK)

On increasing the temperature from 25 to60, the increase in the current is mainly due to increase in the leakage. Ap per the excel sheet attached with EE-293(estimating power for BF561), the static current increase from 170mA @ 25C to arounf 270mA @ 60C. So you should ideally see anincrease of around 100 mA when the temperature increase form 25 to 60C.

For the parts where the current consumption increases form 400 to 800 mA, have measured what is the value of VDDINT on processor pin.

DO you see any change in the voltage level- VDDINT as compared to other boards which only show 450 mA. Are these boards functioning properly at 60C?

Is there a chance that something(power regulator etc.) is breaking on these boards @ 60C

What is the exact part number you are using?

Regards,

Nabeel

Thanks Nabeel,

CCLK=459MHz, SCLK = 114.75MHz.

For the parts where the current consumption increases form 400 to 800 mA:

1. VDDINT = 1.27V, do not change. Yes, these boards functioning are properly at 60C

2. No.

3. the part number is ADSP-BF561 SBBCZ-5A 0.5 #1410

Regards,

Jiulu

Hello Jiulu,

Each individual part has a slightly different leakage power profile due to slight manufacturing variability in the transistor switching rate on each die. Faster transistors tend to leak more. The table that Nabeel is referring to gives a maximum static (deep sleep) current specification for each junction temperature (Tj). You can try putting the processor in deep sleep mode (by following the steps shown in the Hardware Reference manual) and then measuring the power to see if the difference is fully explained by static power.

In order to match your setup to the table you would have to take an accurate case temperature measurement on the processor package (tCASE). I believe the temperature numbers you're giving are ambient temperature, which can't be used to accurately compute current consumption. Please refer to the Environmental Conditions of the data sheet for the equation that relates case temperature (the temperature you can measure on the processor package) to junction temperature. Once you have taken the deep sleep current measurement and computed the junction temperature you can make sure that the data you're seeing is lower than the maximum static current specified in the application note.

Regards,

Joe

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin