If you connect the probe of the Dso150 to the positive and negative of the 9v power where the dso is connected the 7660 will short circuit to ground (as written in the 7660 specs) and destroied.
This is what i've verified personally during the tests. Replaced the smd responsible of the positive to negative conversion it's everything ok now. (Dso150 June 2017 version).
Dso150 the 7660smd is destroied
Re: Dso150 the 7660smd is destroied
What happened, happened, but I have difficulties understanding how this can happen. The DSO150 has a fairly high input impedance, so how can it cause problem for the ICL7660?
Even if you accidently connected the GND lead to the +9V, it could maybe blow a trace, if the power supply is powerful; else it will just drop the +9V to zero, equivalent to switching it off.
If you connected the GND lead to the -9V, the ICL7660 spec says that its output is capable of withstanding a continuous short circuit.
Even if you accidently connected the GND lead to the +9V, it could maybe blow a trace, if the power supply is powerful; else it will just drop the +9V to zero, equivalent to switching it off.
If you connected the GND lead to the -9V, the ICL7660 spec says that its output is capable of withstanding a continuous short circuit.
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Re: Dso150 the 7660smd is destroied
Don't know Mat but it happened. I was really disappointed and discovered the issue not obtaining the negative voltages in the testing points. Measuring the voltages directly to the 7660 pins i've discovered it was blowed.MatNieuw wrote:What happened, happened, but I have difficulties understanding how this can happen. The DSO150 has a fairly high input impedance, so how can it cause problem for the ICL7660?
Even if you accidently connected the GND lead to the +9V, it could maybe blow a trace, if the power supply is powerful; else it will just drop the +9V to zero, equivalent to switching it off.
If you connected the GND lead to the -9V, the ICL7660 spec says that its output is capable of withstanding a continuous short circuit.
I've replaced with another one and.....i don't plan to repeat the test but the ground risks with oscilloscopes is something potentially existing.