March 11, 2014 – Linear Technology Korea (CEO Hong Sa-gwak) announced the launch of an integrated ride-through DC/DC system IC (product name: LTC3355).

The LTC3355 provides the features of a main buck regulator with an embedded boost converter for temporary backup of VOUT, or ride-through, when VIN power is suddenly lost from a single supercapacitor energy source. This device includes all essential functions required to provide complete charging of the supercapacitor (or other energy storage element), namely monitoring of VIN and VOUT, and automatic switchover for backup power. The LTC3355's asynchronous fixed-frequency current-mode monolithic 1A buck switching regulator provides regulated output voltage of 2.7V to 5V from a maximum 20V input power supply. The device is ideal for ride-through, "dying gasp," or data backup power supplies used in power meters, industrial alarms, and SSDs (solid state drives).

The LTC3355 uses a 1A programmable constant-current/constant-voltage (CC/CV) linear charger powered from VOUT to charge a single supercapacitor, electrolytic capacitor, or NiMH battery. A temperature control loop limits die temperature to 110°C while maximizing charging current. When the VIN power supply drops below the programmable power-fail comparator input (PFI) threshold, the device's fixed-frequency asynchronous current-mode 5A boost switching regulator supplies power from the supercapacitor to VOUT. Backup power can be supplied to VOUT utilizing capacitor voltage as low as 0.5V. The device features programmable boost, charger, and VIN current limiting functions. Additional features include VIN power-fail indicator, VCAP power-good indicator, and VOUT power-on reset (POR) output.

The LTC3355 is available in a thermally enhanced 20-pin low-profile (0.75mm) 4mm x 4mm QFN package. The device operates over a junction temperature range of -40°C to 125°C and is available now.

Photo caption: Integrated Ride-Through DC/DC System IC