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 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 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.
Documentation & Resources
R540 Reliability Data3/26/2018
DC1887A - Demo Manual4/14/2014
Backup Power Solutions7/13/2017
Take Advantage of Supercaps2/10/2016
Low Profile Supercapacitor Power Backup with Input Current Limiting11/1/2015 LT Journal
Tools & Simulations
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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.