20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator
Features and Benefits
- High Efficiency Synchronous Step-Down CC/CV Charging of One to Four Series Supercapacitors
- Step-Up Mode in Backup Provides Greater Utilization of Stored Energy in Supercapacitors
- 14-Bit ADC for Monitoring System Voltages/Currents, Capacitance and ESR
- Active Overvoltage Protection Shunts
- Internal Active Balancers—No Balance Resistors
- VIN: 4.5V to 35V, VCAP(n): Up to 5V per Capacitor, Charge/Backup Current: 10+A
- Programmable Input Current Limit Prioritizes System Load Over Capacitor Charge Current
- Dual Ideal Diode PowerPath™ Controller
- All N-FET Charger Controller and PowerPath Controller
- Compact 38-Lead 5mm × 7mm QFN Package
The LTC3350 is a backup power controller that can charge and monitor a series stack of one to four supercapacitors. The LTC3350’s synchronous step-down controller drives N‑channel MOSFETs for constant current/constant voltage charging with programmable input current limit. In addition, the step-down converter can run in reverse as a step-up converter to deliver power from the supercapacitor stack to the backup supply rail. Internal balancers eliminate the need for external balance resistors and each capacitor has a shunt regulator for overvoltage protection.
The LTC3350 monitors system voltages, currents, stack capacitance and stack ESR which can all be read over the I2C/SMBus. The dual ideal diode controller uses N-channel MOSFETs for low loss power paths from the input and supercapacitors to the backup system supply. The LTC3350 is available in a low profile 38-lead 5mm × 7mm × 0.75mm QFN surface mount package.
- High Current 12V Ride-Through UPS
- Servers/Mass Storage/High Availability Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration circuit 1937B is a supercapacitor charger and backup controller with supercapacitor health and system monitoring; featuring the LTC3350. The LTC3350 has a 10.8V to 20VIN, 5.3A buck supercapacitor charger, a 25W output backup boost controller and an input ideal diode to disconnect the input supply in backup mode. An output ideal diode allows the supercapacitors to supply the output when VCAP is above the set backup voltage. As the capacitor stack voltage drops down to the set output voltage, the LTC3350 will operate as a boost regulator to supply the output until the energy in the supercapacitors are depleted.
Software & Systems Requirements
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:
Product Selector Card (1)
Technical Articles (1)
Press Release (1)
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.