LT3464 Micropower Boost Converter with Schottky and Output Disconnect in ThinSOT FEATURES DESCRIPTIO n Tiny Solution Size The LT 3464 is a micropower step-up DC/DC converter n Low Quiescent Current with integrated Schottky diode and output disconnect 25A in Active Mode packaged in an 8-lead low profile (1mm) SOT-23. The 0.5A in Shutdown Mode small package size, high level of integration, and the use n Internal 115mA, 36V Switch of tiny SMT components yield a solution size of less than 2 n Integrated Schottky Diode 40mm . The LT3464 has a typical current limit of 115mA n Integrated PNP Output Disconnect with as well as fast switching speed to allow the use of a chip Short-Circuit Protection inductor and small ceramic capacitors. The internal PNP n Internal Reference Override Pin disconnects the output load from the input during shut- n 16V at 8mA from 3.6V Input down, and also provides output short-circuit protection. n 12V at 20mA from 5V Input An auxiliary reference input allows the user to override the n Input Range: 2.3V to 10V internal 1.25V feedback reference with any lower value, n High Output Voltage: Up to 34V allowing full control of the output voltage during opera- n Low Profile (1mm) SOT-23 Package tion. This device features a low 25A quiescent current, which is further reduced to less than 0.5A in shutdown. U A current limited fixed off-time control scheme conserves APPLICATIO S operating current, resulting in high efficiency over a broad n OEL Panel Bias range of operating current. The rugged 36V switch and n LCD Bias output disconnect circuitry allow outputs up to 34V to be n Handheld Computers easily generated in a simple boost topology. n Battery Backup , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technolgy Corporation n Digital Cameras n Cellular Phones TYPICAL APPLICATIO Efficiency 22H 90 V IN 2.3V TO 10V V = 8.4V IN 80 V SW IN V = 4.2V IN V OUT OUT 70 16V CTRL 0.22F 1F 60 LT3464 CAP 3.48M 0.33F SHDN 50 FB GND 294k 40 3464 TA01a 30 0.01 0.1 1 10 100 LOAD CURRENT (mA) 3464 TA01b 3464f 1 EFFICIENCY (%) U ULT3464 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V , SHDN, CTRL Voltage ........................................ 10V IN TOP VIEW NUMBER OUT, CAP Voltage .................................................... 36V CTRL 1 8 SHDN SW Voltage .............................................................. 36V LT3464ETS8 FB 2 7 V IN OUT 3 6 SW FB Voltage ................................................................. 6V GND 4 5 CAP Maximum Junction Temperature .......................... 125C TS8 PART MARKING TS8 PACKAGE Operating Temperature Range (Note 2) .. 40C to 85C 8-LEAD PLASTIC SOT-23 LTG2 Storage Temperature Range ..................65C to 150C T = 125C, = 140C/W, = 85C/W JMAX JA JC Lead Temperature (Soldering, 10 sec).................. 300C Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 3.6V, unless otherwise noted. (Note 2) A IN PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Input Voltage 2.0 2.3 V Quiescent Current Not Switching 25 36 A V = 0.2V 0.01 0.5 A SHDN FB Comparator Trip Voltage V Falling, V = 3.6V l 1.215 1.250 1.275 V FB CTRL FB Comparator Hysteresis 10 mV FB Pin Bias Current V = 1.25V, V = 3.6V l 330 nA FB CTRL FB Voltage Line Regulation 2.3V < V < 10V 0.05 0.1 %/V IN Switch Off Time V -V = 5V 250 ns CAP IN V -V = 0V 1.0 s CAP IN Switch Leakage Current V = 36V 0.02 1 A SW Switch V I = 80mA 190 300 mV CESAT SW Switch Current Limit 85 115 140 mA Schottky Forward Voltage I = 110mA 600 750 mV SCHOTTKY Schottky Reverse Leakage V = 36V 1 10 A CAP-SW PNP Disconnect V I = 200A 100 mV CAP-OUT OUT I = 10mA 190 mV OUT PNP Disconnect Q Current I = 0, V = 36V (Note 3) 1.5 5 A OUT CAP PNP Disconnect Leakage SHDN = 0.2, V = 10V, V = 0V 0.1 5 A CAP OUT PNP Disconnect Current Limit V = 10V, V = 0V 25 45 75 mA CAP OUT SHDN Pin Current V = 3.6V 5 10 A SHDN SHDN Input Voltage High 2.3 V SHDN Input Voltage Low 0.2 V CTRL Pin Bias Current V = 0.5V, V = 1V l 680 nA CTRL FB CTRL to FB Offset V = 0.5V (Note 4) 2 7 mV CTRL Note 1: Absolute Maximum Ratings are those values beyond which the life Note 3: Current consumed by Disconnect PNP when there is no load on of a device may be impaired. the OUT pin. Note 2: The LT3464E is guaranteed to meet performance specifications Note 4: This figure is computed according to ((V falling + V rising)/2) FB FB from 0C to 70C. Specifications over the 40C to 85C operating V . CONTROL temperature range are assured by design, characterization and correlation with statistical process controls. 3464f 2 U WWW