This circuit design was based on the previous posting (see DRV110EVM: DRV110 14 pin). Here it the updated design:
The expected values are as follows:
Ckeep = 100ms
I peak = 32 ma
I hold = 16 ma
Fosc = 25 kHz
Problem#1 is I hold = ~5ma and drops the solenoid contact. Additionally, very noisy hold current. Here is a screen shot of the trace. Blue is current probe of the solenoid. Yellow trace is the enable.
Problem #2 is that Ckeep =~80ms
Next, all I did was add a .1uf cap in location C133 and here are the results:
By decreasing R hold (R164) to 90K ohms I can get the solenoid hold current up to ~16ma.
What are your thoughts on the circuit not functioning as intended?