MAXREFDES1151, Reference Design includes two parts, the first part uses the MAX406 to charge the supercapacitors with 1A constant current, the second part uses the MAX1725 and MAX985 to realize dv/dt suppression. The MAX406 is a single, low-voltage, micropower, precision op amp designed for battery-operated systems. It features a supply current of less than 1.2 uA that is relatively constant over the entire supply range, which represents a 15 to 20 times improvement over industry-standard micropower op amps. A unique output stage enables this op amp to operate at ultra-low supply current while maintaining linearity under loaded conditions. In addition, the output is capable of sourcing 1.8mA when powered by a 9V battery
