Can a supercapacitor be used as a backup power supply?

The backup power supply circuit could be made less complex and take up less space if a single supercapacitor is employed instead of two or more. Such an arrangement eliminates the need for supercapacitor balancing.

What is a capacitor based backup system?

Capacitor based backup systems use a different methodology. Unlike battery based systems which provide continuous power during the entire backup time, capacitor based systems require only short-term backup power in order to transfer volatile data into flash memory or provide “dying gasp” alarm operation for a minimum necessary amount of time.

Should a backup power supercapacitor be exposed to ripple current?

Because of this short time constant, the designer should ensure that the backup power supercapacitor is not exposed to a continuous ripple current, as damage may result. Supercapacitors can operate between 0 volts and their maximum rated capacity.

How long does a supercapacitor backup last?

The duration of backup depends on the supercapacitor’s energy reserve and the system power draw. The features of the Maxim Integrated products allow for maximum backup power from a single 2.7-volt supercapacitor, while reducing the number of circuit components by eliminating the need for separate charger and boost devices, and diodes.

What is a reversible regulator in a supercapacitor power backup circuit?

Figure 6: When used in a supercapacitor power backup circuit, MAX38889 (or MAX38888) reversible regulators eliminate the need for separate charger and boost devices and diodes. (Image source: Maxim Integrated)

Can a diode power a supercapacitor?

Diodes allow either the primary power source or the supercapacitor to power the system (Figure 5). Figure 5: Using a single supercapacitor in a power backup circuit eliminates the need for cell balancing but requires a step-up regulator to boost the supercapacitor’s output voltage.