Hello,
This question probably applies to all of the Siglent SDS1000X-E (and possibly other models?) scopes.
Got a new Siglent SDS1204X-E and trying to do some battery lifetime estimates with it for a coin cell powered MCU device and associated sensors that I'm working on. So using a uCurrent (early version, not Gold, but good enough) to show current draw on wake from sleep and other events.
I've got the probe on channel 1 setup in 1X mode to reduce noise and connected it to the uCurrent. I've also set channel 1 to use A(mp) rather than the default V(olt) settings for measurements. All working well so far when using the uCurrent in 1mV/mA setting. I've setup an Integral Math channel that is nicely showing the energy usage in uAs or mAs when triggering on my different types of events.
When I put the uCurrent in 1mV/uA mode to measure some of the really low power events and sleeping, obviously all the measurements shown by channel 1 and the Math function are out by 1000.
On a GW Instek scope I've used, I'm able to use a wider range of probe multipliers, specifically 0.001X to then show measurement values in 1mV/uA mode. This means all measurements etc. are showing in uA instead of mA. This also includes the values the Math channel is calculating, which is great for getting on overall energy usage for battery lifetime estimations for different types of events. For example I have a series of low power sensor readings that take 583ms with different current levels being drawn throughout the period and the Math Integral function nicely accumulates all of this for me in the appropriate uAs or mAs depending on final value.
On the Siglent, while there are many multipliers for the probe/channel values to go much higher, e.g. 10X up to 10,000X, the lowest it will go is only to 0.1X. Even if I put the probe in 10X mode combined with 0.1X, I'm still only getting an effective division of 100, rather than the needed 1000 when using the uCurrent in uA mode. Also putting the probe in 10X is increasing the noise as well, so I want to avoid this as there are relatively fast changes occurring throughout some of the measured events.
Do I just need to resign to having to convert everything (div by 1000) when working in uA mode with the uCurrent on the Siglent SDS1000X-E series?
Or is this something that can be added to a firmware update to have additional channel multipliers for probes, ideally, down to .001X if possible? If so, who do I need to send this request to?
I realise also that I can have the Math channel do a multiplier on CH1 values to reduce the readings from channel 1 by 1000. But then I can't run another Integral Math channel on the first Math channel's result to get the overall energy usage for each event. I don't think these Siglent models have a powerful enough set of Math functions to combine it this way. So a better outcome would be to just use a channel/probe multiplier of 0.001X while running the probe in 1X connected to the uCurrent in 1mV/uA mode. Then all the measurements and Math functions will show the actual values I'm after.
Thoughts?