LM7705MM/NOPB (TEXAS INSTRUMENTS)

The LM7705MM/NOPB is a switched capacitor charge-pump Voltage Inverter with a low noise, -0.23V fixed negative voltage regulator. This device is designed to be used with low voltage amplifiers to enable the amplifiers output to swing to zero volts. The -0.23V is used to supply the negative supply pin of an amplifier while maintaining less than 5.5V across the amplifier. Rail-to-rail output amplifiers cannot output 0V when operating from a single-supply voltage and can result in error accumulation due to amplifier output saturation voltage being amplified by following gain stages. A small negative supply voltage will prevent the amplifiers output from saturating at zero volts and will help maintain an accurate zero through a signal processing chain. Additionally, when an amplifier is used to drive an input of the ADC, the amplifier can output a zero voltage signal and the full input range of an ADC can be used. The LM7705 device has a shutdown pin to minimize standby power consumption.