Hello I was wondering if possible I could get some help understanding this chip. The LS1205EV has a programmable ILIM pin for adjusting the current limit. Is there a way to control that pin using a MCU instead of a resistor?
Hi Leviathan,
Welcome to the Tech Forum.
According to the datasheet, the current limit can be adjusted from between 1A and 5A via a resistor, with 10.5k Ohms corresponding to 1A and 2.1k Ohms for 5A.
I can think of a few different ways to adjust this with an MCU, depending on your requirements. If you only need a few different discrete values, you could place a few resistors on your board of the appropriate values and use a switch (digitally controlled analog switch, MOSFETs, etc.) connected to a few I/O’s of your MCU to connect the desired value to the iLimit pin of the LS1205EV. You may even be able to use I/O pins as a virtual ground and connect the resistors directly between I/O pins and iLim without need of a switch. As a logic low on an I/O pin can never quite get down to zero volts, using these pins directly may not give quite as accurate results, but it may well be good enough.
If you need to be able to select any value within that range (within a reasonable resolution), you could use a digital potentiometer and just send the desired value via its serial port.