skarthikbecool
Newbie level 5
Hello Team,
I have the existing circuit as like attached and we wanted to interface the solenoid valve with below requirement.
Solenoid Valve current control requirement :
Load current range 0-1.5A
The regulated load current with resolution of 0.78125mA/bit with a 0.2ohm sense resistor actuator
HS or LS can be controlled
Need current closed loop control
Hence i am doing the compatibility analysis.
My circuit will with stand the load current up to 4A. So no issue with maximum current requirement.
But i wanted to calculate the regulated load current control resolution.
Hence i first i calculated the current sensing resolutions like below.
Microcontroller ADC resolution – 12 bit, 2^12 = 4096
ADC reference voltage – 5V
amplifier gain – 14
I typ = (ADC_value * 1.221mV)/ Gain * shunt = 2.3815 mA
I one bit change = ( (ADC_VaLue-1) * 1.221mV)/ Gain * shunt = 2.3810 mA
Current Sensing Resolution / bit = I typ - I one bit change = 0.58mA
From the above calculation i came to conclusion that my HS current sensing Resolution can meet requirement
As a next step i wanted calculate the Load current control resolution?
Hence i would like to know whether my approach is correct on this compatibility study?
If so then how i should calculate the the Load current control resolution for the given circuit?
I have the existing circuit as like attached and we wanted to interface the solenoid valve with below requirement.
Solenoid Valve current control requirement :
Load current range 0-1.5A
The regulated load current with resolution of 0.78125mA/bit with a 0.2ohm sense resistor actuator
HS or LS can be controlled
Need current closed loop control
Hence i am doing the compatibility analysis.
My circuit will with stand the load current up to 4A. So no issue with maximum current requirement.
But i wanted to calculate the regulated load current control resolution.
Hence i first i calculated the current sensing resolutions like below.
Microcontroller ADC resolution – 12 bit, 2^12 = 4096
ADC reference voltage – 5V
amplifier gain – 14
I typ = (ADC_value * 1.221mV)/ Gain * shunt = 2.3815 mA
I one bit change = ( (ADC_VaLue-1) * 1.221mV)/ Gain * shunt = 2.3810 mA
Current Sensing Resolution / bit = I typ - I one bit change = 0.58mA
From the above calculation i came to conclusion that my HS current sensing Resolution can meet requirement
As a next step i wanted calculate the Load current control resolution?
Hence i would like to know whether my approach is correct on this compatibility study?
If so then how i should calculate the the Load current control resolution for the given circuit?