The FAN3988 is a USB-connection-monitoring device used to determine if a standard USB device or a battery-charging device is connected. The FAN3988 sets the FLAG1 pin to logic HIGH or LOW as an indicator to the system controller that a standard USB device or a charger is connected to the USB port. The FAN3988 also monitors the V for over- or under-voltage conditions. The FLAG2 pin is set LOW if V is less than 3.3 V or greater than 6.0 V. The FAN3988 is packaged in a very small 6-lead MLP package suitable for small board space applications, such as mobile phones.