Tool/software:
Our application uses an 8962 to drive four different solenoids. Each solenoid will have a different expected current utilization.
We want to use the IPROPI line to measure current utilization during the initial activation phase of the solenoid to detect whether the plunger actually moved.
On a successful activation (where the plunger moves fully), the current should ramp up, then fall off while the plunger moves then start going up again after movement stops.
An unsuccessful activation looks different.
The EE who designed the circuit sized the Ripropi resistor based on the 'Current Regulation' section of the datasheet and came up with 7.68K for a circuit expected to draw a maximum of 2A.
When the IPROPI line is connected to an AtoD input on the CPU, it just reads zero continuously when the solenoid is activated.
Looking at the datasheet, it looks like it may be necessary to use a different equation for Ripropi when you desire to use IPROPI for current sensing rather than current regulation.
Is this true? It looks like a much smaller value for Ripropi may be necessary.
Thank you.