We made some small changes to the Mini Ultra 8 MHz Plus board which involves the charging circuitry on the board.<\/p>\n
The Li-Ion\/Pol charger IC (MCP73831) used in the previous revision is now replaced with MCP73871<\/a> to provide system load sharing functionality. This feature is useful if you wanted to ensure system load gets the priority over battery charging process. On top of that, the MCP73871 provides\u00a0autonomous power source selection between the external DC input or battery. This allow us to remove the manual power selection jumper which was present in the first release. Other fancy features includes 3 LED that indicates the input power status, charging process status, and fault status. We have also configure the charging process to take place when the temperature is between 0 and 45\u00a0\u00b0C to ensure that the Li-Ion\/Pol charging temperature range is adhere to.<\/p>\n Unfortunately, \u00a0the MCP73871 introduces an extra 28\u00a0\u03bcA of quiescent current. During the power down mode of ATmega328P and with no external DC input source is available, the total current now is 35.7\u00a0\u03bcA. Although that is comparably higher than our Mini Ultra 8 MHz<\/a>, we believe it is most suitable when used with an external DC source like a \u00a0small solar panel to charge the battery over time.<\/p>\n