27th October 2005, 15:14 #1
Full Member level 4
nano ampere meter
i want to design an digital ampere meter with following specification:
digital nano ammeter ( 1 - 999 nA)
pico Ammeter (1-999 pA),
i will be using lcd display and 89c51 microcontroller.
please any body help me out for how to design it.
27th October 2005, 15:14
27th October 2005, 17:48 #2
Advanced Member level 5
pico ampere meter
I think you should use an analog front-end, followed by and A/D.
Take a look at appnote AN-242 from National.
You can probably adapt circuits of figures 11, 12, or 14. Use their output to drive the A/D.