MAX1795/MAX1796/Low-Supply Current, Step-Up DC-DC ConvertersMAX1797with True ShutdownGeneral DescriptionFeatures The MAX1795/MAX1796/MAX1797 are high-efficiency, ● > 95% Efficiency step-up DC-DC converters intended for small portable ● True-Shutdown Circuitry hand-held devices. These devices feature Maxim’s True • Output Disconnects from Input in Shutdown Shutdown™ circuitry, which fully disconnects the out- • No External Schottky Diode Needed put from the input in shutdown, improves efficiency, and eliminates costly external components. All three ● 25μA Quiescent Supply Current devices also feature Maxim’s proprietary LX-damping ● Low-Noise Antiringing Feature circuitry for reduced EMI in noise-sensitive applications. ● LBI/LBO Comparator Enabled in Shutdown For additional in-system flexibility, a battery monitoring comparator (LBI/LBO) remains active even when the ● 2μA Shutdown Current DC-DC converter is in shutdown. ● 8-Pin μMAX Package The input voltage range is +0.7V to VOUT, where VOUT can be set from +2V to +5.5V. Startup is guaranteed Ordering Information from +0.85V. The MAX1795/MAX1796/MAX1797 have a PARTTEMP RANGEPIN-PACKAGE preset, pin-selectable 5V or 3.3V output. The output can also be adjusted to other voltages, using two external MAX1795 EUA -40°C to +85°C 8 μMAX resistors. The three devices differ only in their current MAX1796 EUA -40°C to +85°C 8 μMAX limits, allowing optimization of external components for MAX1797 EUA -40°C to +85°C 8 μMAX different loads: The MAX1795, MAX1796, and MAX1797 have current limits of 0.25A, 0.5A, and 1A, respectively. All devices are packaged in a compact, 8-pin μMAX package that is only 1.09mm tall and half the size of an 8-pin SO. Applications ● Portable Digital Audio Players ● PDAs/Palmtops ● Wireless Handsets ● Portable Terminals Pin ConfigurationTypical Operating Circuit IN 0.7V TO TOP VIEW 5.5V BATT LX LBI 1 8 BATT MAX1795 FB 2 MAX1795 7 OUT OUT OUT LBI MAX1796 LBO 3 MAX1796 6 LX FB MAX1797MAX1797 LBO SHDN 4 5 GND OFF SHDN µMAX ON GND True Shutdown is a trademark of Maxim Integrated Products. 19-1798; Rev 0; 12/00