CAT661

www.DataSheet4U.com CAT661 High Frequency 100mA CMOS Charge Pump, Inverter/Doubler FEATURES s Converts V+ to V- or V+ to 2V+ s Low output resistance, 10Ω max. s High power efficiency s Selectable charge pump frequency of 25kHz H GEN FR ALO EE LE A D F R E ETM s Pin-compatible to MAX660, LTC660 with higher frequency operation s Available in 8-pin SOIC andDIP packages s Lead-free, halogen-free package option or 135kHz; optimize capacitor size. s Low quiescent current APPLICATIONS s Negative voltage generator s Voltage doubler s Voltage splitter s Low EMI power source s GaAs FET biasing s Lithium battery power supply s Instrumentation s LCD contrast bias s Cellular phones, pagers DESCRIPTION The CAT661 is a charge-pump voltage converter. It can invert a positive input voltage to a negative output. Only two external capacitors are needed. With a guaranteed 100mA output current capability, the CAT661 can replace a switching regulator and its inductor. Lower EMI is achieved due to the absence of an inductor. In addition, the CAT661 can double a voltage supplied from a battery or power supply. Inputs from 2.5V to 5.5V will yield a doubled, 5V to 11V output. A Frequency Control pin (BOOST/FC) is provided to select either a high (typically 135kHz) or low (25kHz) internal oscillator frequency, thus allowing quiescent current vs. capacitor size trade-offs to be made. The 135kHz frequency is selected when the FC pin is connected to V+. The operating frequency can also be adjus...