LT1302/LT1302-5 Micropower High Output Current Step-Up Adjustable and Fixed 5V DC/DC Converters DESCRIPTIO FEATURES n 5V at 600mA or 12V at 120mA from 2-Cell Supply The LT 1302/LT1302-5 are micropower step-up DC/DC n 200A Quiescent Current converters that maintain high efficiency over a wide n Logic Controlled Shutdown to 15A range of output current. They operate from a supply n Low V Switch: 310mV at 2A Typical voltage as low as 2V and feature automatic shifting CESAT TM n Burst Mode Operation at Light Load between Burst Mode operation at light load, and current n Current Mode Operation for Excellent mode operation at heavy load. Line and Load Transient Response The internal low loss NPN power switch can handle n Available in 8-Lead SO or PDIP current in excess of 2A and switch at frequencies up to n Operates with Supply Voltage as Low as 2V 400kHz. Quiescent current is just 200A and can be further reduced to 15A in shutdown. APPLICATI S Available in 8-pin PDIP or 8-pin SO packaging, the LT1302/ LT1302-5 have the highest switch current rating of any n Notebook and Palmtop Computers similarly packaged switching regulators presently on the n Portable Instruments market. n Personal Digital Assistants n Cellular Telephones , LTC and LT are registered trademarks of Linear Technology Corporation. n Flash Memory Burst Mode is a trademark of Linear Technology Corporation. P CA A L AT TY I L PP IC I 2-Cell to 5V Converter Efficiency NC L1 65 10H 90 V I IN T 7 3 88 SW SHDN SHUTDOWN C3 LT1302-5 86 V = 3V IN 0.1F 8 4 C1 PGND SENSE 84 2 CELLS D1 100F V = 2.5V IN GND V C 82 1 2 V = 2V IN 80 R C 20k 78 C2 C C 100F 0.01F 76 74 72 OUTPUT 5V 70 LT1302 F01 600mA 1 10 100 1000 C1 = C2 = SANYO OS-CON D1 = MOTOROLA MBRS130LT3 LOAD CURRENT (mA) L1 = COILTRONICS CTX10-3 LT1302 TA02 COILCRAFT DO3316-103 Figure 1. 2-Cell to 5V/600mA DC/DC Converter 1 EFFICIENCY (%) + + UO UO ULT1302/LT1302-5 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO TOP VIEW V Voltage ............................................................. 10V ORDER PART IN NUMBER SW Voltage ............................................................. 25V GND 1 8 PGND FB Voltage .............................................................. 10V V 2 7 SW C LT1302CN8 SHDN 3 V SHDN Voltage ......................................................... 10V 6 IN LT1302CS8 (SENSE*)FB 4 5 I V Voltage ................................................................ 4V T C LT1302CN8-5 I Voltage .................................................................. 4V T N8 PACKAGE S8 PACKAGE LT1302CS8-5 8-LEAD PDIP 8-LEAD PLASTIC SO Maximum Power Dissipation ............................ 700mW *FIXED VERSION S8 PART MARKING Operating Temperature Range .................... 0C to 70C PINS 1 AND 8 ARE INTERNALLY CONNECTED IN SOIC PACKAGE Storage Temperature Range ............... 65C to 150C 1302 T = 125C, = 100C/W (N8) JMAX JA Lead Temperature (Soldering, 10 sec)................. 300C T = 125C, = 80C/W (S8) 13025 JMAX JA Consult factory for Industrial and Military grade parts. LECTR AL CHARACTERIST DC E IC ICS T = 25C, V = 2.5V, unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current V = 0.5V, V = 1.3V l 200 300 A Q SHDN FB V = 1.8V l 15 25 A SHDN V Input Voltage Range 2.0 V IN l 2.2 8 V V Feedback Voltage (LT1302) V = 0.4V l 1.22 1.24 1.26 V FB C Feedback Pin Bias Current (LT1302) V = 1V 100 nA FB Output Sense Voltage (LT1302-5) V = 0.4V l 4.85 5.05 5.25 V C Output Ripple Voltage (LT1302-5) V = 0.4V 50 mV C Sense Pin Resistance to Ground (LT1302-5) 420 k V Offset Voltage See Block Diagram 15 mV OS Comparator Hysteresis (Note 1) 5 mV Oscillator Frequency Current Limit Not Asserted (Note 2) 175 220 265 kHz l 160 310 kHZ DC Maximum Duty Cycle 75 86 95 % t Switch On Time Current Limit Not Asserted 3.9 s ON t Switch Off Time 0.7 s OFF Output Line Regulation 2 < V < 8V l 0.06 0.15 %/V IN V Switch Saturation Voltage I = 2A 310 400 mV CESAT SW l 475 mV Switch Leakage Current V = 5V, Switch Off l 0.1 10 A SW Switch Current Limit V = 0.4V (Burst Mode Operation) 1 A C V = 1.25V (Full Power) (Note 3) l 2.0 2.8 3.9 A C Error Amplifier Voltage Gain 0.9V V 1.2V, V /V 50 75 V/ V C C FB V Shutdown Pin High l 1.8 V SHDNH V Shutdown Pin Low l 0.5 V SHDNL I Shutdown Pin Bias Current V = 5V l 820 A SHDN SHDN V = 2V 3 A SHDN V = 0V l 0.1 1 A SHDN I Pin Resistance to Ground 3.9 k T The l denotes specifications which apply over the 0C to 70C Note 2: The LT1302 operates in a variable frequency mode. Switching temperature range. frequency depends on load inductance and operating conditions and may be above specified limits. Note 1: Hysteresis is specified at DC. Output ripple depends on capacitor size and ESR. Note 3: Minimum switch current 100% tested. Maximum switch current guaranteed by design. 2 U WU U W W W