ILC6390

www.DataSheet4U.com www.fairchildsemi.com ILC6390/91 SOT-89 Step-Up PFM Switcher with Auto-Load Sense Features 85% conversion efficiency at 50mA out Start-up voltages as low as 900mV ±2.5% accurate outputs Complete switch design with only 3 external components 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 mA boost converter using Pulse Frequency Modulation, or PFM, technique, in 5-lead SOT-89 or a 5-lead SOT-23 package. Only 3 external components are needed to complete the switcher design. The ILC6390 automatically senses load variations to choose between 55% and 75% duty cycles. Normal operation is 55% duty at 155kHz; when load currents exceed the internal comparator trip point, a “turbo mode” kicks in to provide extended on-time switching (75% duty at 100kHz 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 SD 3 1 CE V 3 2 1 OUT L: ...