STR751 ADC and Power Supply Question

[mail13]

Posted on January 25, 2008 at 08:24

STR751 ADC and Power Supply Question

[mail13]

Posted on January 25, 2008 at 07:05

I need some help to understand the datasheet of the STR751 ARM, because some sentences are very unclear:

There is said that the VDDA_ADC and VSSA_ADC pins are the analog power supply of the A/D converter cell, but how can I set the reference-Voltage? I need 0-5V Measurement.

There is a chapter named ''Power supply schemes'' but there is nothing said about the STR751-µC -> Does it work with 5V?

Can I set VDDA_ADC higher than VDD_IO?

Why is USB disabled in 5V-Mode?

[jgoril]

Posted on January 25, 2008 at 08:24

Reference manual says that VDDA_ADC must be equal to VDD_IO. Since it is ''sensitive'' supply, you can use better filtering for this pin. That's all...

I'm in doubt whether you will find any answer for your second question - Why is USB disable in 5V mode...