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 adjusted with an external capacitor at the OSC pin or by driving OSC with an external clock.8-pin SOIC package is available.The CAT661 can replace the MAX660 and the LTC660 in applications where higher oscillator frequency and smaller capacitors are needed. In addition, the CAT661 is pin compatible with the 7660/1044, offering an easy upgrade for applications with 100mA loads.