I am designing a charger that will charge a NiMH battery pack that looks much like two AA packaged together. I've chosen the DS2711 for the charging IC but I've come across a snag that I can't figure out. I will be using a USB cable to charge it so I will have a 5V 500mA output to deal with. There is a sample circuit that Maxim provided on the datasheet but I'm not sure what to do with the feed back signal and the ICHG signal. Could someone help me in the right direction? Thank you!

 

USB will default to 100 - 200mA.

 

I've done tests in the past and found that almost every USB port in my company's office would provide 500mA when asked.

 

As long as your USB slave device asks for it.

 

Instead of limiting myself to a USB port, how can I make a current control circuit using the FB and ICHG lines with a higher powered 5V source? The datasheet is at the following link:http://datasheets.maxim-ic.com/en/ds/DS2711-DS2712.pdf I built off of figure 3 on page 7. Help is very appreciated.