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→Introduction
The concept schematic here described provides some hints about possible implementations of backup power supply for [[LCC USB SSD (DUL)|DUL]] module.
Four different options are shown, based on capcitors capacitors or battery. These are briefly described in the following sections. Two options are provided for main power supply (5V): it can be connected to USB VBUS (USB_VBUS) or to external power supply (EXT_5V) via J22 jumper. Main power supply is used to charge auxiliary energy storage device via J23. J24 is used to select which energy storage device is connected to backup power supply input of DUL. J19 is reference of LCC-68 socket where DUL can be plugged. MOD1 is reference of DUL module when soldered on PCB directly. R25, R26, R28 and R31 allow to connect USB bus to socket or soldered-down DUL module. DL5, DL6, DL7 and DL8 are staus LEDs connected rispectively to the following signals of DUL:* STAT2#* WARN#* STAT1#* LED_0J18 and J20 are provided to enable read-only modes as described [[LCC_USB_SSD_(DUL)#Read-only_modes|here]].
==Options #1: supercap==
==Options #2: bestcap==