LTC1515 Series Step-Up/Step-Down Switched Capacitor DC/DC Converters with Reset DESCRIPTION FEATURES n Adjustable/Selectable 3V, 3.3V or 5V The LTC 1515, LTC1515-3/5 and LTC1515-3.3/5 are Output Voltages micropower switched capacitor DC/DC converters that n 2V to 10V Input Voltage Range produce a regulated output voltage by either stepping up n Up to 50mA Output Current or stepping down the input voltage. Output voltage is n Only Three External Capacitors Required adjustable using an external resistor divider (LTC1515) or n Soft Start Limits Inrush Current at Turn-On programmable to either 3V/5V (LTC1515-3/5) or 3.3V/5V n Low Operating Current: 60A (LTC1515-3.3/5) using a logic pin. n Very Low Shutdown Current: < 1A A unique architecture allows the parts to accommodate a n Shutdown Disconnects Load from V IN wide input voltage range (2V to 10V) while maintaining n V Programmable to 3V/5V or 3.3V/5V OUT 4% regulation. Additional circuitry prevents excessive n Short-Circuit and Overtemperature Protected inrush current and output voltage ripple when large V to IN n 650kHz Switching Frequency V differentials are present. OUT n Open-Drain Power-On Reset Output n Daisy-Chained Control Outputs An internal power-on reset circuit forces the POR pin low Available in SO-8 Package on initial power-up. The POR output remains low until 200ms (typ) after V is in regulation. U OUT APPLICATIONS The parts are short-circuit and overtemperature protected. n SIM Interface in GSM Cellular Telephones Battery life is maximized by very low operating currents n Smart Card Readers (I = 60A typ, I < 1A in shutdown). All three parts are CC CC n Local Power Supplies available in an SO-8 package. n Portable Equipment , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION LTC1515-X 5V Output vs Input Voltage Programmable 3.3V/5V Power Supply with Power-On Reset 5.2 100k I = 10mA OUT 5/3 = 3V 1 8 V = 3.3V OR 5V OUT 5.1 ON OFF SHDN V OUT I = 50mA OUT 2 7 RESET POR V IN + + V LTC1515-3.3/5 IN 3 6 5.0 + 10F 10F 4-CELL 5V 3.3V 5/3 C1 NiCd 0.22F 4 5 GND C1 4.9 LTC1515 TA01 4.8 2 3 4 5 6 7 8 9 10 INPUT VOLTAGE (V) LT1515 TA02 1 OUTPUT VOLTAGE (V) U ULTC1515 Series ABSOLUTE MAXIMUM RATINGS (Note 1) Operating Temperature Range V to GND................................................ 0.3V to 12V Commercial ............................................. 0C to 70C IN V to GND ............................................. 0.3V to 12V Industrial ............................................ 40C to 85C OUT SHDN, 5/3, FB to GND .............................. 0.3V to 12V Storage Temperature Range ................ 65C to 150C V Short-Circuit Duration............................. Indefinite Lead Temperature (Soldering, 10 sec)................. 300C OUT PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER ORDER PART TOP VIEW TOP VIEW NUMBER LTC1515CS8-3/5 SHDN 1 8 V OUT SHDN 1 8 V OUT LTC1515CS8-3.3/5 LTC1515CS8 POR 2 7 V IN POR 2 7 V IN LTC1515IS8-3/5 LTC1515IS8 + + 5/3 C1 3 6 FB C1 3 6 LTC1515IS8-3.3/5 GND C1 4 5 GND C1 4 5 S8 PART MARKING S8 PART MARKING S8 PACKAGE S8 PACKAGE 8-LEAD PLASTIC SO 8-LEAD PLASTIC SO 151535 1515 515I35 T = 125C, = 110C/W JMAX JA T = 125C, = 110C/W JMAX JA 515335 1515I 15I335 Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS V = 2V to 10V, SHDN = 3V, C1 = 0.22F, C = C = 10F unless otherwise noted (Note 2). IN IN OUT PARAMETER CONDITIONS MIN TYP MAX UNITS V Operating Voltage V = 5V l 2.7 10 V IN OUT V = 3V/3.3V l 2.0 8 V OUT V = ADJ l 2.0 10 V OUT V = 3V (LTC1515-3/5) 2V V 8V, I 15mA l 2.88 3.0 3.12 V OUT IN OUT 3V V 8V, I 50mA l 2.88 3.0 3.12 V IN OUT V = 3.3V (LTC1515-3.3/5) 2V V 8V, I 15mA l 3.17 3.3 3.43 V OUT IN OUT 3V V 8V, I 50mA l 3.17 3.3 3.43 V IN OUT V = 5V (LTC1515-3/5, LTC1515-3.3/5) 2.7V V 10V, I 15mA l 4.8 5.0 5.2 V OUT IN OUT 3.3V V 10V, I 50mA l 4.8 5.0 5.2 V IN OUT V Feedback Voltage LTC1515, V Ramping Negative l 1.190 1.232 1.275 V FB FB V Feedback Hysteresis LTC1515 1 % FB Effective Output Resistance LTC1515, V = 3V, Step-Up Mode l 30 IN V Operating Current V 5V, I = 0, SHDN = 3V l 60 100 A IN IN OUT V > 5V, I = 0, SHDN = 3V l 75 135 A IN OUT V Shutdown Current SHDN = 0V, V 5V l 1 A IN IN SHDN = 0V, V > 5V 25 A IN Output Ripple Full Load (Note 2) 100 mV P-P Switching Frequency Full Load l 500 650 800 kHz 5/3, SHDN Input Threshold V l 0.4 1.0 V IL V l 1.0 1.6 V IH 5/3, SHDN Input Current 5/3, SHDN = V l 1 1 A IN 5/3, SHDN = 0V l 1 1 A FB Input Current FB = 1.232V l 50 50 nA POR Output Low Voltage I = 100A, V = 3V l 0.05 0.4 V SINK IN 2 U WU U WWW