CATAT71991 Datasheet | Chip Advanced Technology

Description The CAT71991 is a high efficiency and up to 2A output current step-down DC/DC converter series that integrates a low on resistance NMOS on high side. Including on the substrate with the listed features is a high performance trans-conductance error amplifier that provides tight voltage regulation and accuracy under transient conditions. An under voltage lockout circuit is built in to prevent start up until the input voltage reaches to 4.75V. Other features include an over current protection and thermal shutdown. The CAT71991 is available in an 8 pins SOIC package. Application ‹ Set-Top-Box, DVD, LCD Displays ‹ High Power LED Power Supply ‹ Distributed Power System ‹ Data m. x DSL CPE Pin Configuration Features ‹ High Efficiency up to 92% ‹ 4.75V to 23V Wide Input Voltage Range ‹ Output Adjustable from 1.23 to 17V ‹ 2.0A Output Current ‹ 380k Hz constant Frequency Operation ‹ Current Mode Control ‹ Over-temperature Protection ‹ Over Current Protection ‹ Under Voltage Lockout ‹ 25μA Shutdown Current ‹ CAT71991 with Soft Star Function ‹ SOP8 Package ‹ Ro HS pliant (100% Green available) Ordering Information Part Number CAT71991CA Package SOP8 Ship 2500/ Tape & Reel Typical Application Efficiency Table Efficiency (%) Efficiency VS Output Current at VIN=12V 100 90 80 70 60 50 40 0 5V 3.3V 1.8V 0.5 1 1.5 Output Current (A) The CAT logo is a registered trademark of Chip Advanced Technology 2008 Chip Advanced Technology Inc. - All Right Reserved. 8/28/2008 Rev:0.85 2/16 2.0A 380KHz 23V High Efficiency Step-Down DC/DC Converter CAT71991 Pin Description Pin Symbol Description Connect SS to an external capacitor to control soft-start timing. If SS is open, 1 SS internal soft-start about 160u S will be used. High Side Gate Drive Boost Input. A capacitor must be connected from SW to BS. 2 BS This capacitor boosts the gate drive to the internal NMOS above VIN to fully turn it ON. 3 VIN Power Supply Pin. The input voltage for the power supply is...