Max input voltage for ADC input on microcontroller

Status
Not open for further replies.
lloydi12345 said:
Yes.

I hope its alright to ask this one. Do you know what's the dead voltage level of 6v SLA batteries? So I can prompt the user that he needs to recharge the battery.
Click to expand...

hi,
For 6V SLA batteries never let them discharge to less 5.4V, I would recommend 5.6V as a minimum then recharge
 
Last edited:
lloydi12345 said:
You also said this one on your earlier post. Is it bad to power a device say 5v from regulated 6v lead acid battery?
Click to expand...

I dont think I said that.???

If you used a low voltage drop 5V regulator, say one that had a drop out of 0.2V a 6V SLA battery would be OK.

A standard 7805 Vreg would not work with a 6V SLA battery.
 
Last edited:
ericgibbs said:
I dont think I said that.???

If you used a low voltage drop 5V regulator, say one that had a drop out of 0.2V a 6V SLA battery would be OK.

A standard 7805 Vreg would not work with a 6V SLA battery.
Click to expand...

Sorry for the late reply, now I see. Thank you for all the explanations.
 
Last edited:
Just an FYI,
I applied 12V direct (25A) to a 16F ADC input. The PIC lives on. The entire ADC system is now dead though, on all inputs. It's as though the PIC has no ADC. I can do regular Digital I/O .
 
Mosaic said:
Just an FYI,
I applied 12V direct (25A) to a 16F ADC input. The PIC lives on. The entire ADC system is now dead though, on all inputs. It's as though the PIC has no ADC. I can do regular Digital I/O .
Click to expand...

Hi Mosaic, Did you use also any voltage divider for your 12v?
 
Mosaic said:
Just an FYI,
I applied 12V direct (25A) to a 16F ADC input. The PIC lives on. The entire ADC system is now dead though, on all inputs. It's as though the PIC has no ADC. I can do regular Digital I/O .
Click to expand...

ADC can not be above VDD by more then .5 volts. If he had used a voltage divider that lower it to 5.5 volts His ADC would still work.
I have killed the ADC missed the MCLR pin and hooked it to PORTA.0 So i know you can blow it.
The chip was running code that used RA0 for ADC and I went to reprogram and popped the adc.
 
lloydi12345 said:
Hi Mosaic, Did you use also any voltage divider for your 12v?
Click to expand...

Obviously not, otherwise it wouldn't have been damaged, even a simple series resistor would have protected it as well - and 12V direct from a large battery is obviously a LOT more dangerous than just 6V.
 
Status
Not open for further replies.

Similar threads

  • Question
PIC input low/high voltage level of limit.
Replies
5
Views
2K
Peet19
  • Question
Input output multiplier
Replies
10
Views
11K
danadak
C
  • Question
Choosing right unit for midi controlled pseudo plc.
Replies
9
Views
3K
granddad
N
  • Question
Some Advice please on older boards
2
Replies
27
Views
2K
NoobyMarty
N
  • Question
Inside the Microcontroller!
Replies
18
Views
3K
Electroenthusiast
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…