DESCRIPTION
The LM7705 is a switched capacitor 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 −0.23 volts is used to supply the negative supply pin of an amplifier while maintaining less then 5.5 volts across the amplifier.
Rail-to-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 ADC’s input, it can output a zero voltage signal and the full input range of an ADC can be used.
The LM7705 has a shutdown pin to minimize standby power consumption.
DESCRIPTION
- Regulated Output Voltage −0.232V
- Output Voltage Tolerance 5%
- Output Voltage Ripple 4 mVPP
- Max Output Current 26 mA
- Supply Voltage 3V to 5.25V
- Conversion Efficiency up to 98%
- Quiescent Current 78 µA
- Shutdown Current 20 nA
- Turn on Time 500 µs
- Operating Temperature Range −40°C to 125°C
- 8-Pin VSSOP Package
APPLICATIONS
- True Zero Amplifier Output
- Portable Instrumentation
- Low Voltage Split Power Supplies
LM7705MME/NOPB datasheet
