Texas Instruments LM7705 | Demoboard ADC3663EVM

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. 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 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.

Features

• 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

Typical applications

• Low-Voltage Split-Power Supplies
• Portable Instrumentation

More information

• Datasheet
• IC product information