Milpitas, Calif.Linear Technology Corp. has introduced the LTC3225, an inductorless programmable supercapacitor charger for addressing high peak power and battery backup needs in portable applications.
The device employs a low-noise charge-pump architecture to charge two supercapacitors in series to a fixed output voltage (4.8V/5.3V selectable) from a 2.8V to 5.5V input supply. Charge current is resistor programmable up to 150mA, and the device's automatic cell balancing feature maintains equal voltages on both cells (2.4V/2.65V selectable) without requiring balancing resistors. This protects each supercapacitor from overvoltage damage caused by mismatches in cell capacitance or leakage while minimizing current drain on the capacitors. The LTC3225 will not discharge the supercapacitors when the input supply is removed or shorted to ground.
The LTC3225 operates with a very low 20µA quiescent current when the output voltage is in regulation and draws only 2µA from VOUT. Current is further reduced when the input supply is removed as the IC automatically enters a low current shutdown state, drawing less than 1µA from the supercapacitors. The basic charging circuit requires only three external components and takes up little space; the IC is offered in a tiny 6mm² footprint DFN package.
The LTC3225 is housed in a compact 10-lead, low-profile (0.75mm) 2mm x 3mm DFN package, and operation from -40°C to 85°C ambient temperature is guaranteed.
Pricing: Starts at $2 each in 1,000-piece quantities.
Datasheet: Click here.
Linear Technology, www.linear.com