AT1780

www.DataSheet4U.com AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Features 1.6A,0.21Ω,14V Power MOSFET Operating input voltage:+2.6V to +5.5V Adjustable Output from VIN to 12V 640kHz /1.2MHz pin selectable switching Frequency 0.1μA shutdown Current Built-in Soft-Start function Small 8-Pin MSOP Package General Description The AT1780 is a current-mode step-up DC/DC converter with a 1.6A, 0.21Ω power MOSFET. The soft-start function is programmed with an external capacitor, which sets the input current ramp rate. It is ideal for generating bias voltages for LCD panels. Pin selectable frequency 640KHz or 1.2MHz operation results in a low noise output that is easy to filter and faster loop performance. An external compensation pin provides the user flexibility in determining loop dynamics, allowing the use of small, low equivalent series resistance (ESR) ceramic output capacitors. *Protected by U.S. Patent # 6,791,368 Applications LCD Displays Digital Cameras Portable Applications Hand-Held Devices Block Diagram VIN COMP SHDN Power ON/OFF Reference 1.24V SOFTSTART 4uA SS BIAS + Enable Error Amplifier FB 1.24V gm + + Clock Comparator R Q N LX S GND FSLC Oscillator Ramp Generator + + CURRENT SENSE Aimtron reserves the right without notice to change this circuitry and specifications. 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: ...