LM7705

+

-

+ In

- In

shutdown

low voltage

amplifier

true zero

output voltage

-V

+V

+V

-0.23V

SD

LM7705

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SNVS420B – NOVEMBER 2008 – REVISED MARCH 2013

LM7705 Low Noise Negative Bias Generator

Check for Samples: LM7705

1

FEATURES

DESCRIPTION

The LM7705 is a switched capacitor voltage inverter

2

•

Regulated Output Voltage

−0.232V

with a low noise,

−0.23V fixed negative voltage

•

Output Voltage Tolerance 5%

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

•

Max Output Current 26 mA

the

negative

supply

pin

of

an

amplifier

while

•

Supply Voltage 3V to 5.25V

maintaining less then 5.5 volts across the amplifier.

•

Conversion Efficiency up to 98%

Rail-to-Rail output amplifiers cannot output zero volts

when operating from a single supply voltage and can

•

Quiescent Current 78 µA

result in error accumulation due to amplifier output

•

Shutdown Current 20 nA

saturation voltage being amplified by following gain

•

Turn on Time 500 µs

stages. A small negative supply voltage will prevent

the amplifiers output from saturating at zero volts and

•

Operating Temperature Range

−40°C to 125°C

will help maintain an accurate zero through a signal

•

8-Pin VSSOP Package

processing chain. Additionally, when an amplifier is

used to drive an ADC’s input, it can output a zero

APPLICATIONS

voltage signal and the full input range of an ADC can

•

True Zero Amplifier Output

be used. The LM7705 has a shutdown pin to

minimize standby power consumption

•

Portable Instrumentation

•

Low Voltage Split Power Supplies

Typical Application

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2008–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.