MC9S12XEP100 voltage supply

[ernestsnaith]

Can the MC9S12XEP100 operate using a 3.3V supply rather than 5V? Are there any disadvantages if so other than signal/noise ratio.

Cheers

[DPB]

Hello

The MC9S12XEP100 can operate from a 3.3V supply.

The electrical parameter section in appendix A of the reference manual contains separate parameters for 3.3V  and 5V where differences exist....
http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC9S12XEP100RMV1.pdf?fpsp=1

The internal digital logic sees the same regulated voltage (1.8V). This is not effected by changing the input supply from 5V to 3.3V. So the internal digital operation, including maximum operating frequency, is the same.

Some points to note are...
The minimum operating voltage is 3.13V.
When supplying 3.3V to VDDR,VDDX and VDDA the low voltage detect/interrupt never asserts, as it is connected to VDDA and has a trigger level above 4V.
The I/O pin parameters are specified separately for 3.3V (Table A-7)
The ATD parameters are specified separately for 3.3V (Table A-18)
VDDX-VSSX filter capacitors are important with 3.3V on VDDX because the device is closer to the LVR level.
Expansion bus timing is specified separately for 3.3V.

DPB