
Linear Technology
DESCRIPTION
The LTC
®
3225/LTC3225-1 are programmable supercapaci
tor chargers designed to charge two supercapacitors in
series to a selectable fixed output voltage (4.8V/5.3V for
the LTC3225 and 4V/4.5V for the LTC3225-1) from input
supplies as low as 2.8V to 5.5V. Automatic cell balancing
prevents overvoltage damage to either supercapacitor. No
balancing resistors are required.
FEATURES
Low Noise Constant Frequency Charging of Two Series Supercapacitors
Automatic Cell Balancing Prevents Capacitor Overvoltage During Charging
Programmable Charge Current (Up to 150mA)
Selectable 2.4V or 2.65V Regulation per Cell(LTC3225)
Selectable 2V or 2.25V Regulation per Cell(LTC3225-1)
Automatic Recharge
IVIN= 20μA in Standby Mode
ICOUT< 1μA When Input Supply is Removed
No Inductors
Tiny Application Circuit (2mm ×3mm DFN Package, All Components <1mm High)
APPLICATIONS
Current Limited Applications with High Peak Power Loads (LED Flash, PCMCIA Tx Bursts, HDD Bursts, GPRS/GSM Transmitter)
Backup Supplies