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 fi 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 fl ying capacitor, one bypass capacitor at n Automatic Recharge V and one programming resistor) make the LTC3225/ n I = 20μA in Standby Mode IN VIN LTC3225-1 ideally suited for small battery-powered n I < 1μA When Input Supply is Removed COUT applications. n No Inductors n Tiny Application Circuit (2mm × 3mm DFN Package, Charge current level is programmed with an external All Components <1mm High) resistor. When the input supply is removed, the LTC3225/ LTC3225-1 automatically enter a low current state, drawing APPLICATIONS less than 1μA from the supercapacitors. 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 GPRS/GSM Transmitter) Technology Corporation. All other trademarks are the property of their respective owners. n Backup Supplies TYPICAL APPLICATION Charging Profi le with 30% Mismatch in Output Capacitance, CTOP < CBOT VOUT VIN SHDN VIN COUT 4.8V/5.3V (LTC3225) 2.8V/3V TO 5.5V 5V/DIV 2.2μF 0.6F 4V/4.5V (LTC3225-1) + C LTC3225 CX 1μF LTC3225-1 0.6F IVIN 300mA/DIV C– GND 100k ON/OFF SHDN PGOOD VCOUT 2V/DIV OUTPUT VSEL PROGRAMMING PROG 3225 TA01a VTOP-VBOT 200mV/DIV 12k LTC3225 5 SEC/DIV 3225 TA01b VSEL = VIN RPROG = 12k CTOP = 1.1F CBOT = 1.43F CTOP INITIAL VOLTAGE = 0V CBOT INITIAL VOLTAGE = 0V 3225fb 1 LTC3225/LTC3225-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) VIN, COUT to GND ......................................... –0.3V to 6V TOP VIEW SHDN, VSEL ......................................–0.3V to VIN + 0.3V + C 1 10 COUT C Short-Circuit Duration ............................. Indefi nite – OUT C 2 9 VIN IVIN Continuous (Note 2) ......................................350mA CX 3 11 8 GND IOUT Continuous (Note 2) .....................................175mA SHDN 4 7 PROG Operating Temperature Range (Note 3).... –40°C to 85°C PGOOD 5 6 VSEL Storage Temperature Range ...................–65°C to 125°C DDB PACKAGE 10-LEAD (3mm s 2mm) PLASTIC DFN TJMAX = 125°C, θJA = 76°C/W 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 –40°C to 85°C LTC3225EDDB-1#TRMPBF LTC3225EDDB-1#TRPBF LFFS 10-Lead (3mm × 2mm) Plastic DFN –40°C to 85°C TRM = 500 pieces. Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. Consult LTC Marketing for information on lead based fi nish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/ ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 3.6V, CIN = 2.2μF, CFLY = 1μF, unless otherwise specifi ed (Note 3). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS LTC3225 l VIN-UVLO Input Supply Undervoltage Lockout VSEL = VIN 2.65 2.75 2.85 V l High-to-Low Threshold VSEL = 0 2.4 2.5 2.6 V VIN-UVLO-HYS Input Supply Undervoltage Lockout VSEL = VIN 150 mV Hysteresis VSEL = 0 140 mV l VIN Input Voltage Range VSEL = VIN 3 5.5 V l VSEL = 0V 2.8 5.5 V l VCOUT Charge Termination Voltage VSEL = VIN 5.2 5.3 5.4 V l Sleep Mode Threshold (Rising Edge) VSEL = 0V 4.7 4.8 4.9 V VCOUT-HYS Output Comparator Hysteresis 100 mV l VTOP/BOT Maximum Voltage Across Each of the VSEL = VIN 2.75 V l Supercapacitors After Charging VSEL = 0V 2.5 V LTC3225-1 l VIN-UVLO Input Supply Undervoltage Lockout VSEL = VIN 2.25 2.35 2.45 V l High-to-Low Threshold VSEL = 0 2.0 2.1 2.2 V VIN-UVLO-HYS Input Supply Undervoltage Lockout VSEL = VIN 150 mV Hysteresis VSEL = 0 140 mV 3225fb 2 LTC3225/LTC3225-1 ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 3.6V, CIN = 2.2μF, CFLY = 1μF, unless otherwise specifi ed (Note 3). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS l VIN Input Voltage Range VSEL = VIN 2.8 5.5 V l VSEL = 0 2.8 5.5 V l VCOUT Charge Termination Voltage VSEL = VIN 4.4 4.5 4.6 V l Sleep Mode Threshold (Rising Edge) VSEL = 0 3.9 4.0 4.1 V VCOUT-HYS Output Comparator Hysteresis 100 mV l VTOP/BOT Maximum Voltage Across Each of the VSEL = VIN 2.35 V l Supercapacitors After Charging VSEL = 0 2.1 V LTC3225/LTC3225-1 l IQ-VIN No Load Operating Current at VIN IOUT = 0mA 20 40 μA l ISHDN-VIN Shutdown Current SHDN = 0V, VOUT = 0V 0.1 1 μA l ICOUT COUT Leakage Current VOUT = 5.6V, SHDN = 0V 1 3 μA l VOUT = 5.6V, Charge Pump in Sleep Mode 2 4 μA VOUT = 5.6V, SHDN Connected to VIN with 1 μA Input Supply Removed IVIN Input Charge Current VIN = 3.6V, RPROG = 12k, CTOP = CBOT 306 mA VIN = 3.6V, RPROG = 60k, CTOP = CBOT 55 mA IOUT Output Charge Current VIN = 3.6V, RPROG = 12k, CTOP = CBOT, 125 150 175 mA VOUT = 4.5V (LTC3225), VOUT = 3.7V (LTC3225-1) VIN = 3.6V, RPROG = 60k, CTOP = CBOT, 26 mA VOUT = 4.5V (LTC3225), VOUT = 3.7V (LTC3225-1) l VPGOOD PGOOD Low Output Voltage IPGOOD = –1.6mA 0.4 V l IPGOOD-LEAK PGOOD High Impedance Leakage Current VPGOOD = 5V 10 μA l VPG PGOOD Low-to-High Threshold Relative to Output Voltage Threshold 92 94 96 % l VPG-HYS PGOOD Threshold Hysteresis Relative to Output Voltage Threshold 0.25 1.2 2.5 % ROL Effective Open-Loop Output Impedance VIN = 3.6V, VOUT = 4.5V (LTC3225) 8 Ω (Note 4) VIN = 3.6V, VOUT = 3.7V (LTC3225-1) 9 l fOSC CLK Frequency 0.6 0.9 1.5 MHz VSEL, SHDN l VIH Input High Voltage 1.3 V l VIL Input Low Voltage 0.4 V l IIH Input High Current –1 1 μA l IIL Input Low Current –1 1 μA Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: The LTC3225/LTC3225-1 are tested under pulsed load conditions may cause permanent damage to the device. Exposure to any Absolute such that TJ ≈ TA. The LTC3225/LTC3225-1 are guaranteed to meet Maximum Rating condition for extended periods may affect device performance specifi cations from 0°C to 85°C. Specifi cations over the reliability and lifetime. –40°C to 85°C operating temperature range are assured by design, Note 2: Based on long-term current density limitations. characterization and correlation with statistical process controls. Note 4: Output not in regulation; ROL ≡ (2 • VIN – VOUT)/IOUT 3225fb 3 LTC3225/LTC3225-1 TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C, CFLY = 1μF, CIN = 2.2μF, CTOP = CBOT , unless otherwise specifi ed) IOUT vs RPROG IOUT vs VOUT (RPROG = 12k) Effi ciency vs VIN 160 180 100 VIN = 3.6V 90 140 VOUT = 4.5V (LTC3225) 160 80 120 140 70 120 100 LTC3225 60 100 (mA) 80 (mA) 50 LTC3225-1 OUT 80 OUT I 60 I 40 EFFICIENCY (%) 60 30 40 CTOP = CBOT ILOAD = 100mA 40 20 CTOP = CBOT VIN = 2.8V 20 V = V 20 VIN = 3.6V 10 SEL IN V = 0 VIN = 5.5V SEL 0 0 0 10 20 3040 50 60 0 0.5 131.52 2.5 3.5 4 4.5 5 2.5 3 3.5 44.5 5 5.5 RPROG (kΩ) VOUT (V) VIN (V) 3225 G01 3225 G02 3525 G03 Charge Pump Open-Loop Output Extra Input Current vs Output No-Load Input Current vs Resistance vs Temperature Current (IVIN – 2 • IOUT) Supply Voltage (2VIN – VCOUT)/IOUT 7 30 10.0 VIN = 3.6V VIN = 3.6V CHARGE PUMP IS ON 9.5 25 TA = 85°C 6 VOUT = 3.7V V = 5V 9.0 (LTC3225-1) OUT T = 25°C 20 A 5 8.5 (mA) T = –40°C V = 4.5V A IN OUT (Ω) VOUT = 4.5V (μA) 15 8.0 V = 3.7V OL OUT IN (LTC3225) I R 4 7.5 EXTRA I 10 7.0 3 VOUT = 4.2V 5 6.5 2 0 6.0 20 40 60 80100 120 140 160 2.5 3 3.5 4 4.5 5 5.5 –40 –15 1035 60 85 IOUT (mA) VIN (V) TEMPERATURE (°C) 3225 G04 3225 G05 3225 G06 Charging Profi le with Unequal Oscillator Frequency vs Initial Output Capacitor Voltage Supply Voltage Input Ripple and Input Current (Initial VTOP = 1.3V, VBOT = 1V) 0.94 SHDN 5V/DIV V 0.93 IN 20mV/DIV IVIN 300mA/DIV TA = 25°C 0.92 IVIN VCOUT 200mA/DIV 0mA 2V/DIV TA = –40°C 0.91 VTOP-VBOT TA = 85°C 500mV/DIV 0.90 FREQUENCY (MHz) 3225 G08 3225 G09 RPROG = 12k 200ns/DIV LTC3225 2 SEC/DIV VSEL = VIN 0.89 RPROG = 12k CTOP = CBOT = 1.1F C INITIAL VOLTAGE = 1.3V 0.88 TOP C INITIAL VOLTAGE = 1V 2.5 3 3.5 4 4.5 5 5.5 BOT VIN (V) 3225 G07 3225fb 4 LTC3225/LTC3225-1 TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C, CFLY = 1μF, CIN = 2.2μF, CTOP = CBOT , unless otherwise specifi ed) Charging Profi le with Unequal Charging Profi le with 30% Charging Profi le with 30% Initial Output Capacitor Voltage Mismatch in Output Capacitance Mismatch in Output Capacitance (Initial VTOP = 1V, VBOT = 1.3V) (CTOP > CBOT) (CTOP < CBOT) SHDN SHDN SHDN 5V/DIV 5V/DIV 5V/DIV IVIN IVIN IVIN 300mA/DIV 300mA/DIV 300mA/DIV VCOUT VCOUT VCOUT 2V/DIV 2V/DIV 2V/DIV V -V V -V TOP BOT VTOP-VBOT TOP BOT 200mV/DIV 500mV/DIV 200mV/DIV 3225 G11 3225 G12 LTC3225 2 SEC/DIV 3225 G10 LTC3225 5 SEC/DIV LTC3225 5 SEC/DIV VSEL = VIN VSEL = VIN VSEL = VIN RPROG = 12k RPROG = 12k RPROG = 12k CTOP = CBOT = 1.1F CTOP = 1.43F CTOP = 1.1F CTOP INITIAL VOLTAGE = 1V CBOT = 1.1F CBOT = 1.43F CBOT INITIAL VOLTAGE = 1.3V CTOP INITIAL VOLTAGE = 0V CTOP INITIAL VOLTAGE = 0V CBOT INITIAL VOLTAGE = 0V CBOT INITIAL VOLTAGE = 0V PIN FUNCTIONS + C (Pin 1): Flying Capacitor Positive Terminal.