I am interested in understanding how to place the LT3741-1 into current-sink mode. The datasheet mentions that this device can also sink current, but not under what conditions. Is it possible to use the LT3741-1 to force it into sinking a constant current set by the sense resistor and the voltage on CTRL1 pin?
LT3741-1 is not able to sink current. You should use LT3741 for your application.
In order for LT3741 able to sink current , Vfb voltage should be 1.21V < Vfb < 1.5V . This condition is shown on Graph 3741 G14 on page 6 of the datasheet.
Thank you for the reply. I've looked at the plot but I'm not sure how I would use the FB pin to command the LT3741 to sink current. In my application I would be using the LT3741 to supply a constant current to a large capacitor. The current is set by CTRL1. There is a resistor divider at the FB pin to regulate the voltage once the capacitor is charged to the specified voltage. My application requires discharging the same capacitor with a constant current at some point in time. In order to discharge the capacitor at a constant current, should I override the voltage at the FB pin through an external circuit? Bottom line, how would I supply a constant current to a load while ensuing the output voltage does not exceed a specified amount, and be able to discharge that same load with a constant current?
Vout is proportional to the voltage at the FB pin. LT3741 would only be able to sink current if it detects the output voltage is greater than the set voltage (from the resistor divider). The current being sink by LT3741 is set by the difference of the set Vout and actual vout voltage as described by the graph before.
Hello, i am also interested in this feature as constant current sink.
But i dont understand, where the excces energy is going to. Is the LT3741 just opening the low FET with PWM, so that a regulated current is going to GND?
Thx, i understand this part. So when i program with the FB voltage divider 2 Vout and apply a 3,3V/50W power supply to the output, the programmed max current e.g. 5 A is flowing. But where is the power of 3,3V*5A going to be dissipated?