carpenter
Full Member level 6
i need to have the option of MCU to control the power supply with any Buck DC-DC for example **broken link removed** output 0-20V 0-20A, 220 kHz.
This Controller have on FB 800mV Error amplifer and my idea is any as this
R2 R3 is standard voltage divider make from 20V 800mV for FB , FB LM5145 is center resistor divider R2/R3.
R1 and DAC 0-3.3 is used for voltage control. If DAC =0V is output voltage 20V, if is 3.3V is output voltage 0V.
Comparator U1 D1 and R4 (not necessary) us used for Current control
Comparator compare voltage from DAC with voltage from current shunt if is on output overcurrent set over D1 on FB voltage over 800mV .
it will work?
Which bandwith must have a differential amplifier at the shunt?
Otherwise I can use INA225
Full digital current control loop.
Use only voltage control and for control current use digital loop in MCU compare voltage measuren on shunt monitor with set current, if is ovecurrent reduce voltage over DAC on R1 .
INA225 have witch 100V/V bandwith 70kHz, ADC/DAC and MCU procesing I estimate below 5us i.e. 200kHz.
it's a big nonsense?
This Controller have on FB 800mV Error amplifer and my idea is any as this
R2 R3 is standard voltage divider make from 20V 800mV for FB , FB LM5145 is center resistor divider R2/R3.
R1 and DAC 0-3.3 is used for voltage control. If DAC =0V is output voltage 20V, if is 3.3V is output voltage 0V.
Comparator U1 D1 and R4 (not necessary) us used for Current control
Comparator compare voltage from DAC with voltage from current shunt if is on output overcurrent set over D1 on FB voltage over 800mV .
it will work?
Which bandwith must have a differential amplifier at the shunt?
Otherwise I can use INA225
Full digital current control loop.
Use only voltage control and for control current use digital loop in MCU compare voltage measuren on shunt monitor with set current, if is ovecurrent reduce voltage over DAC on R1 .
INA225 have witch 100V/V bandwith 70kHz, ADC/DAC and MCU procesing I estimate below 5us i.e. 200kHz.
it's a big nonsense?