I am using the LT3652 charger chip,datasheet. Now, there is a status pin /CHRG. The pin is -
CHRG (Pin 4): Open-Collector Charger Status Output; typically pulled up through a resistor to a reference voltage. This status pin can be pulled up to voltages as high as VIN when disabled, and can sink currents up to 10mA when enabled. During a battery charging cycle, if required charge current is greater than 1/10 of the programmed maximum current (C/10), CHRG is pulled low. A temperature fault also causes this pin to be pulled low. After C/10 charge termination or, if the internal timer is used for termination and charge current is less than C/10, the CHRG pin remains high-impedance.
Now, an application circuit is as shown below -
Now, it says that the /CHRG pin can sink in a max of 10mAmps and it shows an LED connected to show status. Most SMD LEDs need approx 10mAmps at least to make it turn on. I cannot supply 10mAmps as thats the maximum. So, what practical use could it serve ?