LM7705

Product Folder Order Now Technical Documents Tools & Software Support & Community LM7705 SNVS420D – NOVEMBER 2008 – REVISED MAY 2018 LM7705 Low-Noise Negative Bias Generator 1 Features 1 Regulated Output Voltage −0.232 V Output Voltage Tolerance 5% Output Voltage Ripple 4 mVPP Supply Voltage 3 V to 5.25 V Conversion Efficiency Up to 98% Quiescent Current 78 µA Shutdown Current 20 nA Turnon Time 500 µs Operating Temperature Range −40°C to 125°C 8-Pin VSSOP Package 2 Applications True Zero Amplifier Outputs Portable Instrumentation Low-Voltage Split-Power Supplies 3 Description The LM7705 device is a switched capacitor voltage inverter with a low noise, −0.23 V 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 −0.23 V is used to supply the negative supply pin of an amplifier while maintaining less then 5.5 V across the amplifier. Railto-Rail output amplifiers cannot output zero volts 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 ful...