The LM2687 CMOS Negative Regulated Switched Capacitor Voltage Inverter delivers a very low noise adjustable output for an input voltage in the range of +2.7V to +5.5V. Four low cost capacitors are used in this circuit to provide up to 10mA of output current. The regulated output for the LM2687 is adjustable between -1.5V and -5.2V. The LM2687 operates at 100 kHz (typical) switching frequency to reduce output resistance and voltage ripple. With an operating current of only 500 A (charge pump power efficiency greater than 90% with most loads) and 0.05 A typical shutdown current, the LM2687 provides ideal performance for cellular phone power amplifier bias and other low current, low noise negative voltage needs. The device comes in a small 8-pin MSOP package.