Category: Hardware
Product Number: LT1511
Hi,
We have been using LT1511 in one of our products which is a battery charger for UPS. We want to modify it a bit to reduce the battery charging current and some improvements.
I have some questions regarding the LT1511 design if someone can please help answer.
1- What are the steps to calculate the battery charging current, from the datasheet, figure 1 and block diagram, it seems we have 3 variables Rprog, Rs2 and Rs1. Which one should I select first and and on what assumptions? what are the limitations?
Lets say I want to reduce the charging current to 2A , should I just change the value of Rprog? or I change the values of Rs1 to 0.05R so the voltage across it is 100mV ?
Lets say I want to reduce the charging current to 2A , should I just change the value of Rprog? or I change the values of Rs1 to 0.05R so the voltage across it is 100mV ?
2- How can I calculate the soft start time , what will be the start-up time if I change the capacitor to 1uF?
3- If I pull down the COMP1 pin using 2K resistor, would it disable the adapter current limit even if pin 9 and pin 10 are not connected to Vcc or is it a must to connect them to Vcc if I don't intend to limit the adapter current?
4- Is it possible to design a circuit using this IC to have different charging IC input voltage and different system voltage (load voltage) and then design circuit to limit the input current based on the load power vs battery current.
for example:
System input is 9V - 48V
Charging IC input 24V (24V output from buck / boost converter)
battery voltage 13.8V
now limit the charging IC input current if the system load is increased which works on 9V-48V range.
Thank you