TS-4100 Supercapacitors

This device can optionally support our TS-SILO technology. This consists of a charge and feedback monitor in the supervisory microcontroller on the TS-4100, a dedicated charging circuit on the TS-4100, and a pair of 2.7 V, 25 F supercapacitors in series on a TS-4100 baseboard. This full application provides up to 60 seconds of back up power if external power is removed from the device. Additionally, a notification of power failure is asserted on a CPU GPIO pin when external power has fallen below a valid input level. Monitoring this signal can be used to initiate a proper shutdown and ensure that all data is flushed from cache to disk, and all disks are unmounted properly.

The supercapacitor charge and discharge are monitored by the microcontroller on the TS-4100. A charge cycle is initiated automatically at startup by U-Boot, and can be disabled via a jumper setting on the baseboard. U-Boot can also be configured to load the kernel and FDT, but delay starting them until the supercapacitors are at a specified charge level. This can allow for a guaranteed available amount of reserve power in the case of external power being disconnected once the kernel starts booting.

U-Boot waiting for charge information

Manual enabling and disabling of charging can be handled in U-Boot or Linux userspace:

# Enable the supercapacitor charging cycle in U-Boot or Linux userspace
tsmicroctl -e

# Disable the supercapacitor charging cycle in U-Boot or Linux userspace
tsmicroctl -d

# Get current charge level information from Linux userspace tools
tsmicroctl --info