ILC6390 Datasheet | Fairchild Semiconductor

Features - - - - - 85% conversion efficiency at 50m A out Start-up voltages as low as 900m V ±2.5% accurate outputs plete switch design with only 3 external ponents Automatically senses load variations to select the optimal duty cycle and extend conversion efficiency over a wide range - External transistor configuration to run as switcher controller - Shutdown to 0.5µA Description 50 m A boost converter using Pulse Frequency Modulation, or PFM, technique, in 5-lead SOT-89 or a 5-lead SOT-23 package. Only 3 external ponents are needed to plete the switcher design. The ILC6390 automatically senses load variations to choose between 55% and 75% duty cycles. Normal operation is 55% duty at 155k Hz; when load currents exceed the internal parator trip point, a “turbo mode” kicks in to provide extended on-time switching (75% duty at 100k Hz oscillation). Requiring only 30µA of supply current, the ILC6390 achieves efficiencies as high as 85% at 5V yet shuts down to 0.5µA max. Standard voltages offered are 2.5, 3.3, and 5.0V and is available in both a 5 lead SOT-23 and 5 lead SOT-89 package for small footprint applications. In addition, the ILC6391 is configured to drive an external transistor to achieve higher power levels. Applications - Cellular phones, pagers - Cameras, video recorders - Palmtops and PDAs Typical Applications Figures 1 & 2 3 1 CE V 3 2 1 L: 100µH (SUMIDA, CD-54) SD: Diode (Schottky diode; MATSUSHITA MA 735) L + V IN L V IN ILC6390CM 2 3 ILC6390CP + V OUT CL CL: 16V 47µF (Tantalum Capacitor; NICHICON, f93) SD CE GND 3 2 1 CE V Figures 3 & 4 L: 47µH (SUMIDA, CD-54) SD: Diode (Schottky diode; MATSUSHITA MA735) CL: 16V 47µF (Tantalum Capacitor; NICHICON, F93) RB: 1kΩ CB: 3300p F Tr: 2SC3279, 2SDI628G Rev.1.2 ©2001 Fairchild Semiconductor...