Circuit to measure current consumption of uC

Thomas Guest #2146845
Rate this post
• ▲ useful
▼ not useful 
Hi guys,

I need to design a circuit that measures the power consumption of uP.
The uP has to be supplied by a voltage Vcc, and then using the shunt 
resistor, the current drawn by the uC is converted to a voltage then 
followed to the shunt monitor. The current range I want to measure is 
1nA...150mA which is too large and cannot be reached with only one shunt 
resistor, which is not a big deal first.
I went through all current shunt monitors of TI, simulated them and even 
tested couple of them, but no one can return reasonable results when it 
comes to measure currents from 1uA...10mA

I attached my circuit for your review.
Does any body habe any suggestion how can I reach my goal?!
Thx
Attached files:
Reply Quote Edit Move Thread sperren Anmeldepflicht aktivieren Anpinnen Delete topic Thread mit anderem zusammenführen Report post
henrik Guest #2148254
Rate this post
• ▲ useful
▼ not useful 
1nA :) sounds like fun

Bandwith? Uncertancy?

All will be for naught if you don't monitor the voltage to keep it 
stable....

and take some expensive low leakage components ...

Bop Pease had some stories about low current measurements on components 
and Jim Williams too (on crystals, however always worth the time)

One idea: Take a big (low leakage) cap for the supply of your DUT and 
charge it with a small cap of a (slightly) higher constant voltage, 
controlled by a comparator. The number of charge pulses per time is your 
current.

Tricky is the switch :)

Or take a look at current output DAC ..
Reply Quote Edit Delete Report post
Thomas Guest #2151119
Rate this post
• ▲ useful
▼ not useful 
@oork: this did not work unfortunately
@henrik: I want to have as much accurate results as possible. What do 
you mean with Bandwidth?
@g457: yes but I need the circuit of it. I need to build my own 
circuit...
Reply Quote Edit Delete Report post
Lothar M. Moderator (Company: Titel) #2151134
Rate this post
• ▲ useful
▼ not useful 
g457 wrote:
> http://www.alternatezone.com/electronics/ucurrent/
Thomas wrote:
> @g457: yes but I need the circuit of it. I need to build my own
> circuit...
Just scroll down and you will see this:
http://www.alternatezone.com/electronics/ucurrent/uCurrent%20Schematic.png

BTW: 1nA...150mA
This is a dynamic range of 1:150000000. And that equals more than 27 
bits. A VERY demanding task...
Reply Quote Edit Delete Report post
Watch this topic

Reply

Note: the original post is older than 6 months. Please don't ask any new questions in this thread, but start a new one.

Formatting
  • [c]C-Code[/c]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]
  • [[Title]] – link to an article
  • Link to another post: right-click its post ID (#8078628), copy the address, paste it into the text

More about formatting

Post long source code as an attachment, not in the text.

Your name and e-mail address

Already registered? Log in

Not shown to anyone. We send you a link; your post appears once you confirm it there.

By submitting you create a free account and accept the terms of use.