LTC3225/LTC3225-1 150mA Supercapacitor Charger FEATURES DESCRIPTION n Low Noise Constant Frequency Charging of Two The LTC 3225/LTC3225-1 are programmable supercapaci- Series Supercapacitors tor chargers designed to charge two supercapacitors in n Automatic Cell Balancing Prevents Capacitor series to a selectable xed output voltage (4.8V/5.3V for Overvoltage During Charging the LTC3225 and 4V/4.5V for the LTC3225-1) from input n Programmable Charge Current (Up to 150mA) supplies as low as 2.8V to 5.5V. Automatic cell balancing n Selectable 2.4V or 2.65V Regulation per Cell prevents overvoltage damage to either supercapacitor. No (LTC3225) balancing resistors are required. n Selectable 2V or 2.25V Regulation per Cell Low input noise, low quiescent current and low external (LTC3225-1) parts count (one ying capacitor, one bypass capacitor at n Automatic Recharge V and one programming resistor) make the LTC3225/ IN n I = 20A in Standby Mode VIN LTC3225-1 ideally suited for small battery-powered n I < 1A When Input Supply is Removed COUT applications. n No Inductors n Charge current level is programmed with an external Tiny Application Circuit (2mm 3mm DFN Package, resistor. When the input supply is removed, the LTC3225/ All Components <1mm High) LTC3225-1 automatically enter a low current state, drawing less than 1A from the supercapacitors. APPLICATIONS The LTC3225/LTC3225-1 are available in a 10-lead 2mm n Current Limited Applications with High Peak Power 3mm DFN package. Loads (LED Flash, PCMCIA Tx Bursts, HDD Bursts, L, LT, LTC and LTM are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. GPRS/GSM Transmitter) n Backup Supplies TYPICAL APPLICATION Charging Pro le with 30% Mismatch in Output Capacitance, C < C TOP BOT V OUT V IN SHDN V C 4.8V/5.3V (LTC3225) IN OUT 2.8V/3V TO 5.5V 5V/DIV 4V/4.5V (LTC3225-1) 2.2F 0.6F + C CX LTC3225 I VIN 1F LTC3225-1 0.6F 300mA/DIV C GND 100k V COUT ON/OFF SHDN PGOOD 2V/DIV V OUTPUT SEL PROGRAMMING PROG 3225 TA01a V -V TOP BOT 200mV/DIV 12k 3225 TA01b LTC3225 5 SEC/DIV V = V SEL IN R = 12k PROG C = 1.1F TOP C = 1.43F BOT C INITIAL VOLTAGE = 0V TOP C INITIAL VOLTAGE = 0V BOT 3225fb 1LTC3225/LTC3225-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V , C to GND ......................................... 0.3V to 6V TOP VIEW IN OUT SHDN, V ...................................... 0.3V to V + 0.3V SEL IN + 1 10 C C OUT C Short-Circuit Duration ............................. Inde nite OUT 2 9 C V IN I Continuous (Note 2) ......................................350mA VIN 3 11 8 CX GND I Continuous (Note 2) .....................................175mA 4 7 SHDN PROG OUT 5 6 PGOOD V Operating Temperature Range (Note 3).... 40C to 85C SEL Storage Temperature Range ................... 65C to 125C DDB PACKAGE 10-LEAD (3mm s 2mm) PLASTIC DFN T = 125C, = 76C/W JMAX JA EXPOSED PAD (PIN 11) MUST BE SOLDERED TO LOW IMPEDANCE GND PLANE (PIN 8) ON PCB ORDER INFORMATION Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3225EDDB TRMPBF LTC3225EDDB TRPBF LCYR 10-Lead (3mm 2mm) Plastic DFN 40C to 85C LTC3225EDDB-1 TRMPBF LTC3225EDDB-1 TRPBF LFFS 10-Lead (3mm 2mm) Plastic DFN 40C to 85C TRM = 500 pieces. Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on lead based nish parts. For more information on lead free part marking, go to: