The MC1121 is a charge pump converter with 100mA output current capability. It converts a 2.4V to 5.5V input to a corresponding negative output voltage. As with all charge pump converters, the MC1121 uses no inductors saving cost, size, and reducing EMI. An onboard oscillator operates at a typical frequency of 10kHz (at VDD = 5V) when the frequency control input (FC) is connected to ground. The oscillator frequency increases to 200kHz when FC is connected to VDD, allowing the use of smaller capacitors. Operation at sub10kHz frequencies results in lower quiescent current and is accomplished with the addition of an external capacitor from OSC (pin 7) to ground. The MC1121 can be driven from an external clock connected OSC. Typical supply current at 10kHz is 50A, and falls to less than 1A when the shutdown input is brought low, whether the internal or an external clock is used. The MC1121 is available in a Micro8 package.