I bought a SIM808 module to use it with a PIC microcontroller. Everything works great but now I'm trying to reduce the module power consumption. The module I have is this one from DFRobot. When the module is in power down mode it draws about 60mA!
The datasheet says it should draw 50uA at max in power down mode. I know I'm in power down mode because the network activity LED is off and I haven't powered it up using the PWRKEY. I removed all the LEDs from the board and the active GPS antenna that also draws current. I even removed the buck converter and powered it from a 4V power supply! But I can't go lower than 60mA. The same happens when I put the module in sleep mode, 60mA is the lowest current.
Do I have a faulty module or I'm missing something on the schematic that is drawing so much current? You can download the schematic from here.