ADALM1000 Input/Output Resolution

Hello Stephan,

ADALM1000 uses 16bit converters ( AD5663R for digital to analog conversion and AD7682 for analog to digital conversion)  and offers voltage and current operation from 0 to 5 Volts (V), from -200 to 200 milliamps (mA).

https://ez.analog.com/adieducation/university-program/f/q-a/77892/sensitivity-of-current-measurement-with-adalm1000

The measured values should not differ depending on the software you use.

Regards, 

Andreea

Thank you for your response.

While the board may use 16-bit converters, it's practical resolution is not 16-bit, as stated in the link you provided. There it says the lowest measurable current is closer to 100 uA, or 12-bit. What is the lowest measurable voltage accounting for noise?

In the following link it states "The practical range of test currents from the source in the M1K is 5 mA to 150 mA (or slightly higher)" which was written by dmercer, same user in the link you provided above.

https://ez.analog.com/adieducation/university-program/b/blogs/posts/measure-very-small-resistances-by-building-your-own-milliohm-meter

Is it possible to output currents lower than 5 mA with the ADALM1000 using external circuitry?

Thank you!

Hi:

You asked: "Is it possible to output currents lower than 5 mA with the ADALM1000 using external circuitry?"

The short answers is yes, the operative word being external, depending on the application.

The m1k like any adjustable voltage source / function generator can be used as the control voltage for a voltage to current converter. Do a web search on such circuit techniques, like the well known Howland Current Pump or Source. As a matter of fact ADI supplies the following integrated circuit version.

https://www.analog.com/en/design-center/reference-designs/circuit-collections/lt6375-5ma-howland-current-source.html#cc-overview

Doug

Hi:

You asked: "Is it possible to output currents lower than 5 mA with the ADALM1000 using external circuitry?"

The short answers is yes, the operative word being external, depending on the application.

The m1k like any adjustable voltage source / function generator can be used as the control voltage for a voltage to current converter. Do a web search on such circuit techniques, like the well known Howland Current Pump or Source. As a matter of fact ADI supplies the following integrated circuit version.

https://www.analog.com/en/design-center/reference-designs/circuit-collections/lt6375-5ma-howland-current-source.html#cc-overview

Doug