TC115

TC115 PFM/PWM Step-Up DC/DC Converter Features High Efficiency at Low Output Load Currents via PFM Mode Assured Start-up at 0.9V 80µA (Typ) Supply Current 85% Typical Efficiency at 100mA 140mA Typical Output Current @ VIN = 2.0V Low Power Shutdown Mode No External Switching Transistor Needed Space Saving SOT-89 Package Package Type SOT-89-5 5 GND 4 LX TC115 NC 1 PS 2 SHDN 3 Applications Pagers Cellular Phones Palmtops 1-Cell to 3-Cell Battery Powered Systems Cameras, Video Recorders Local +3V to +5V Supplies General Description The TC115 is a high-efficiency step-up DC/DC converter for small, low input voltage or battery powered systems. This device has a start-up voltage of 0.9V and a typical supply current of 80µA. Phase compensation and soft-start circuitry are included onchip. Unlike conventional PWM step-up converters, the TC115 automatically shifts to pulse frequency modulation (PFM) at low loads, resulting in reduced supply current and improved efficiency. The TC115 requires only an external diode, an inductor, and a capacitor, and supports typical output currents of 140mA. Supply current is reduced to less than 0.5µA, max when SHDN input is brought low. Small size, low installed cost, and low supply current make the TC115 step-up converter ideal for use in a wide range of battery powered systems. Device Selection Table Part Number TC115501ECT TC115331ECT TC115301ECT Output Osc. Voltage Package Freq. (V)* (kHz) 5.0 3.3 3.0 Operating Tem...