Features and Benefits
- VIN Voltage Range: 3V to 20V
- VOUT Voltage Range: 2.7V to 5V
- 1A Current Mode Buck Main Regulator
- 5A Boost Backup Regulator Powered from Single Supercapacitor
- Boost Regulator Operates Down to 0.5V for Maximum Utilization of Supercapacitor Energy
- Programmable Supercapacitor Charge Current to 1A with Overvoltage Protection
- Charger Supports Single Cell CC/CV Battery Charging
- Programmable VIN Current Limit
- Programmable Boost Current Limit
- VIN Power Fail Indicator
- VCAP Power Good Indicator
- VOUT Power On Reset Output
- Compact 20-Lead 4mm × 4mm QFN Package
The LTC3355 is a complete input power interrupt ride-through DC/DC system. The part charges a supercapacitor while delivering load current to VOUT, and uses energy from the supercapacitor to provide continuous VOUT backup power when VIN power is lost. The LTC3355 contains a nonsynchronous constant frequency current mode monolithic 1A buck switching regulator to provide a 2.7V to 5V regulated output voltage from an input supply of up to 20V.
A 1A programmable CC/CV linear charger charges the supercapacitor from VOUT. When the VIN supply drops below the PFI threshold, the devices’s constant frequency nonsynchronous current mode 5A boost switching regulator delivers power from the supercapacitor to VOUT. A thermal regulation loop maximizes charge current while limiting the die temperature to 110°C. The IC has boost, charger and VIN programmable current limits. The LTC3355 is available in a 20-lead 4mm × 4mm QFN surface mount package.
- Ride-Through “Dying Gasp” Supplies
- Power Meters/Industrial Alarms/Solid State Drives
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2040A is a 12V to 4V/1A regulator with an integrated supercap charger and backup boost regulator featuring the LTC3355EUF. The LTC3355 charges up a 3F supercapacitor from the output when the 12V input is available. When the 12V input fails, the backup boost regulator supplies the output until the energy in the supercapacitor is depleted. Figure 2 illustrates how long a 3F supercapacitor can provide a 4W output when the input power fails (~600ms).
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
LTC3355 Companion Parts
Recommended Related Parts
Technical Articles (1)
Rarely Asked Questions (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.