Author Topic: Constant current constant voltage linear supply problems/questions  (Read 3141 times)

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Online PCB.Wiz

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Re: Constant current constant voltage linear supply problems/questions
« Reply #25 on: September 28, 2023, 12:45:38 am »
I will also check that one, main problem with it is that it is not available on LCSC as of now , so i would need to move my order to mouser (  and cheek vs the shipped threshold since i want cheap/free shipment)
PS the LT308x series is in a way voltage controlled via a output current in the uA range so i need to be carefull when i convert it to DACs
The LT308x series are effectively tracking regulators, so an alternative to them that would interface with a DAC could be  tracking regulators.

See :
https://www.mouser.com/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/ldo-voltage-regulators/?q=track&input%20voltage%2C%20max=26%20V~~45%20V&rp=semiconductors%2Fpower-management-ics%2Fvoltage-regulators-voltage-controllers%2Fldo-voltage-regulators%7C~Input%20Voltage%2C%20Max&sort=pricing

https://www.ti.com/power-management/linear-regulators-ldo/products.html?keyMatch=TPS7B4250-Q1&tisearch=search-everything&usecase=GPN-ALT#182=Tracking%20Output&238max=18%3B125&

If you choose ones with separate pins for ADJ and VREF, (eg NCV4254CPDAJR2G, TPS7B4254-Q1  etc)  you can add NPN pass transistors, and dividers to get the FB into DAC range.
No additional opamps are needed, and the reference precision comes via the DAC.
The EN pathway can be driven by current sense.
« Last Edit: September 28, 2023, 02:16:50 am by PCB.Wiz »
 


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