How does it work when negative volts is inputed on ST62T01C in assembly?

jyeonsuk · ‎2005-05-02

Posted on May 03, 2005 at 04:35

jyeonsuk · ‎2005-05-01

Posted on May 02, 2005 at 04:47

Hi everyone,

I have a big problem about negative input volts in assembly on

MCU of ST62T01C.

Normally, the data is 1111 1111(255 decimal) when positive

input volts is 5V and also it is 0000 0000(0 decimal) when input

volts is 0V.

My question is that what digital value is when negative input volts

is -2.5V.

I am wating for your any answer immediately.

Sincerely

From Bob.

:-[

[ This message was edited by: imbob on 02-05-2005 09:22 ]

marco32 · ‎2005-05-01

Posted on May 02, 2005 at 06:04

According to the absloute maximum ratings, you are not allowed a lower input voltage of -0,3V!

To measure -2,5V to +2,5V, you must add the input voltage with 2,5V. So -2,5V will be 0V!

In the software the MSB is the negative flag! (one composite)

jyeonsuk · ‎2005-05-02

Posted on May 02, 2005 at 11:02

Thanks a lot Moppie.

I cofirmed it that Vin is Vss-0.3V to Vss+0.3V on the datasheet of

ST62T01C after your reply. However, could I get one more thing

of it could be possible that Vss can be supplied negative volts?

Thanks again.

Regards.

From Bob.

:D

marco32 · ‎2005-05-02

Posted on May 03, 2005 at 04:35

Yes it can, BUT don't forget the absolute maximum ratings!

The voltage between Vss and Vcc is 7V MAX.

The input and output voltage are related to the Vss and Vcc.

So it can, but take care!