MAX1765 19-1805 Rev 1 4/11 800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear Regulator General Description Features High-Efficiency Step-Up Converter The MAX1765 is a high-efficiency, low-noise, step-up Up to 93% Efficiency DC-DC converter intended for use in battery-powered Adjustable Output from +2.5V to +5.5V wireless applications. This device operates at a high Up to 800mA Output 1MHz fixed frequency while maintaining an exception- PWM Synchronous-Rectified Topology ally low quiescent supply current (200A). Its small 1MHz Operating Frequency (or Sync) external components and tiny package make this device an excellent choice for small hand-held applica- LDO Linear Regulator tions that require the longest possible battery life. 500mA LDO Linear Regulator 2.85V Linear Regulator Output or Adjustable The MAX1765 uses a synchronous-rectified pulse- (1.25V to 5V) width-modulation (PWM) boost topology to generate Low 125mV Dropout at 500mA 2.5V to 5.5V outputs from a wide range of input sources, such as one to three alkaline or NiCd/NiMH +0.7V to +5.5V Input Range cells or a single lithium-ion (Li+) cell. Maxim s propri- 0.1A Logic-Controlled Shutdown etary architecture significantly improves efficiency at Adjustable Inductor Current Limit and Soft-Start low load currents while automatically transitioning to Thermal Shutdown fixed-frequency PWM operation at medium to high load currents to maintain excellent full-load efficiency. 1.5W, 16-Pin TSSOP-EP Package Available Forced-PWM mode is available for applications that require constant-frequency operation at all load cur- Ordering Information rents, and the MAX1765 may also be synchronized to PART TEMP RANGE PIN-PACKAGE an external clock to protect sensitive frequency bands in communications equipment. MAX1765EEE+ -40C to +85C 16 QSOP MAX1765EUE+ -40C to +85C 16 TSSOP-EP* The MAX1765s low-dropout (LDO) linear regulator and DC-DC converter have separate shutdown control. The *EP = Exposed pad. linear regulator s 250m pass device maintains excel- +Denotes a lead(Pb)-free/RoHS-compliant package. lent dropout voltage at currents up to 500mA. The MAX1765 also features analog soft-start and current- Applications limit functions to permit optimization of efficiency, exter- Wireless Handsets Personal nal component size, and output voltage ripple. Communicators PCS Phones The MAX1765 comes in a 16-pin QSOP package and a Hand-Held Instruments Palmtop Computers thermally enhanced 16-pin TSSOP-EP. Portable Audio Players Typical Operating Circuit Pin Configuration TOP VIEW OUT = 3.3V ONA ONL 3.3H POUT (0.7V TO 5.5V) FBL 1 16 ONL LX INL ISET 2 15 TRACK OUT ONB OUTL REF 3 14 CLK/SEL TRACK GND 4 MAX1765 13 INL FB FB 5 12 POUT MAX1765 REF OUT 6 11 LX OUTL = 2.85V ILIM ONA 7 10 PGND OUTL (ADJ 1.25V GND FBL PGND CLK/SEL 8 9 ONB TO 5V) QSOP/TSSOP-EP Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear Regulator ABSOLUTE MAXIMUM RATINGS ONA, ONB, ONL, TRACK, OUT, INL to GND..............-0.3V, +6V Continuous Power Dissipation (T = +70C) A 16-Pin QSOP (derate 8.3mW/C above +70C)...........667mW PGND to GND.....................................................................0.3V LX to GND ...............................................-0.3V to (POUT + 0.3V) 16-Pin TSSOP-EP (derate 19mW/C above +70C) ....1500mW Operating Temperature Range ...........................-40C to +85C OUTL to GND ..............................................-0.3V to (INL + 0.3V) Junction Temperature......................................................+150C CLK/SEL, REF, FB, FBL, ISET, POUT to GND...................................................-0.3V to (OUT + 0.3V) Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C OUTL Short Circuit .....................................................Continuous Soldering Temperature (reflow) .......................................+260C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = V = V = V = V = 3.6V, CLK/SEL = FBL = ONB = TRACK = PGND = GND, ISET = REF (bypassed with OUT POUT INL ONA ONL 0.22F), LX = open, OUTL = open (bypassed with 4.7F), T = 0C to +85C, unless otherwise noted. Typical values are at A T = +25C.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC-DC CONVERTER Input Voltage Range (Note 1) 0.7 5.5 V INL Voltage Range (Note 1) 2.3 5.5 V Minimum Startup Voltage I < 1mA, T = +25C, Figure 2 0.9 1.1 V LOAD A Temperature Coefficient of I < 1mA -2 mV /C LOAD Startup Voltage FB Regulation Voltage V CLK/SEL = OUT, 0 < I < 0.55A 1.215 1.250 1.275 V FB LX FB Input Leakage Current V = 1.35V 0.01 100 nA FB Output Voltage Adjust Range 2.5 5.5 V Load Regulation CLK/SEL = OUT, 0 < I < 800mA -1 % LOAD V V V OUTL OUTL OUTL OUT Voltage in Track Mode V > 2.0V, INL = POUT V OUTL + 0.4 + 0.5 + 0.6 Frequency in Startup Mode f V = 1.5V 125 1000 kHz LX OUT Startup to Normal Mode Rising edge only (Note 2) 2.00 2.15 2.30 V Transition Voltage ISET Input Leakage Current V = 1.25V 0.01 50 nA ISET Supply Current in Normal Mode CLK/SEL = ONL = GND, no load 100 200 A (Note 3) V = 1.5V 130 200 A FB Supply Current in Low-Noise C LK/S E L = OU T, PWM Mode (Note 3) no loa d FB = GN D ( LX swi tchi ng ) 2.5 mA Supply Current in Shutdown ONA = ONL = GND, ONB = OUT 1 10 A 2 MAX1765