MAX1896 19-2221 Rev 1 3/04 1.4MHz SOT23 Current-Mode Step-Up DC-DC Converter General Description Features The MAX1896 step-up DC-DC converter incorporates >90% Efficiency high-performance current-mode, fixed-frequency, Adjustable Output Up to 13V pulse-width modulation (PWM) circuitry and an internal 0.7 N-channel MOSFET to provide a highly efficient Guaranteed 12V/120mA Output from 5V Input regulator with fast response. 2.6V to 5.5V Input Range High switching frequency (1.4MHz) allows fast loop response and easy filtering with small components. The LT1613 Pin Compatible MAX1896 can produce an output voltage as high as 0.01A Shutdown Current 13V from an input as low as 2.6V. Soft-start is program- mable with an external capacitor, which sets the input Programmable Soft-Start current ramp rate. In shutdown mode, current con- Space-Saving 6-Pin SOT23 Package sumption is reduced to 0.01A. The MAX1896 is available in a space-saving 6-pin SOT23 package. The ultra-small package and high switching frequency allow cost and space-efficient implementations. Applications Ordering Information Notebook Computers PART TEMP RANGE PIN-PACKAGE LCD Displays MAX1896EUT-T -40C to +85C6 SOT23-6 PCMCIA Cards Portable Applications Hand-Held Devices Typical Operating Circuit Pin Configuration INPUT 2.6V TO 5.5V TOP VIEW OUTPUT LX16 IN UP TO 13V UP TO 600mA IN LX MAX1896 GND 2 5 SS MAX1896 R1 ON SHDN FB FB34 SHDN OFF SS GND R2 SOT23 Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.1.4MHz SOT23 Current-Mode Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS LX to GND ..............................................................-0.3V to +14V Operating Temperature Range ...........................-40C to +85C IN, SHDN, FB to GND...............................................-0.3V to +6V Junction Temperature......................................................+150C SS to GND ...................................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C IN RMS LX Pin Current ..............................................................0.6A Lead Temperature (soldering, 10s) .................................+300C Continuous Power Dissipation (T = +70C) (Note 1) A 6-Pin SOT23 (derate 9.1mW/C above +70C)...........727mW Note 1: Thermal properties are specified with product mounted on PC board with one square-inch of copper area and still air. 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 = 3V, FB = GND, SS = open, T = 0C to +85C, unless otherwise noted.) IN SHDN A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V 2.6 5.5 Input Supply Range IN V V Circuit of Figure 1 13 Output Voltage Adjust Range OUT V UVLO V rising, 50mV hysteresis 2.25 2.4 2.55 V Undervoltage Lockout IN V IN V = 1.3V, not switching 0.2 0.4 FB Quiescent Current I mA IN V = 1.0V, switching 1 5 FB V = 0, T = +25C 0.01 0.5 SHDN A Shutdown Supply Current A V = 0 0.01 10 SHDN ERROR AMPLIFIER V 1.2 1.24 1.25 Feedback Regulation Set Point FB V I V = 1.24V 21 80 FB Input Bias Current FB FB nA 2.6V < V < 5.5V 0.05 0.20 Line Regulation IN %/V OSCILLATOR f 1000 1400 1800 Frequency OSC kHz DC 82 86 Maximum Duty Cycle % POWER SWITCH I V = 1V, duty cycle = 50% 0.55 0.8 Current Limit (Note 2) LIM FB A R 0.7 1 On-Resistance ON V = 12V, T = +25C 0.1 1 LX A Leakage Current I A LXOFF V = 12V 10 LX SOFT-START 100 Reset Switch Resistance V = 1.2V 1.5 4 7.0 Charge Current SS A CONTROL INPUT V Input Low Voltage IL V V = 2.6V to 5.5V 0.3 V SHDN, IN V Input High Voltage IH V V = 2.6V to 5.5V 1.0 V SHDN, IN V = 3V 25 50 SHDN SHDN Input Current I A SHDN V = 0 0.01 0.1 SHDN 2 MAX1896