I am trying to design a charging circuit for a lithium polymer battery with 2200 mAh capacity and 3.7 V nominal voltage. The integrated circuit for the control of the charge of the battery is the MCP73831 and as a power supply a solar panel of 6.2 Voc and Isc =175 mA is used (I do not have more information about the solar panel). The atmega328p is used as a microcontroller. On the one hand, I want to detect the three states of the tri-state output (pin 1 MCP73831). For this, I used the solution proposed in (How can I read a tristate output with microcontroller? by @Wouter van Ooijen), with the voltage divider connect to microcontroller ADC but I would also like to add a LED connected to pin 1 (STAT) so that it only lights when STAT is a low (not in high impedance). I mainly have two questions (if you see any more mistakes or improvements, I would appreciate it if you told me).
- I have put a zener diode (BZT52H-C5V6) with a Vz = 6 V to ensure that the maximum voltage allowed on pin 4 (MCP73831) is not exceeded. It is right? It is not necessary?
- Would both the led (TLMS1000 red) and the voltage divider work to detect the three states?
Thanks in advance. Best regards.