Features and Benefits
- ±2% Accurate Average Input Current Limit Programmable Up to 3A
- Programmable Maximum Capacitor Voltage Limit
- Active Charge Balancing for Fast Charging of Unmatched Capacitors
- Charges Single or Stacked Capacitors
- VIN Range: 1.73V to 5.5V
- VOUT Range: 1.8V to 5.5V
- <2μA Quiescent Current from VOUT When Charged
- Output Disconnect in Shutdown: <1μA IQ Shutdown
- Power-Good Comparator
- Power Failure Indicator
- Thermally Enhanced 20-Lead (4mm × 5mm × 0.75mm) QFN and 24-Lead TSSOP Packages
The LTC3128 is a highly efficient, buck-boost DC/DC supercapacitor charger. It operates efficiently from input voltages above, below or equal to the output voltage. The LTC3128 incorporates accurate programmable average input current limit, active charge balancing and programmable maximum capacitor voltage. This combination of features makes the LTC3128 ideal for safely charging and protecting large capacitors in backup power systems. The input current limit and maximum capacitor voltage are each programmed using a single resistor. Average input current is accurately controlled over a 0.5A to 3A programmable range while the individual maximum capacitor voltage can be set from 1.8V to 3.0V.
Other features of the LTC3128 include <2μA quiescent current from VOUT in Burst Mode®operation, accurate power-good and power failure indicators, and thermal overload protection. The LTC3128 is offered in low profile, thermally enhanced 20-Lead 4mm × 5mm × 0.75mm QFN and 24-Lead TSSOP packages.
- Supercapacitor Based Backup Power
- Memory Backup
- Servers, RAID, RF Systems
- Industrial, Communications, Computing
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 1887 is a DC/DC supercapacitor buck-boost charger and balancer converter featuring the LTC3128. The DC1887A operates over 1.72V to 5.5V input and charges the output up to 5.5V. Also, the LTC3128 has 2% precision input current limit, which allows the circuit to operate effectively with current limited input power sources like the USB. The 1.2MHz switching frequency operation results in a small and efficient circuit. The converter provides high output voltage accuracy (typically ±2%) over a 1.72V to 5.5V input. The demonstration circuit can be easily modified to generate different output voltages.
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)
Solutions Bulletins & Brochures (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
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.