ADA4077-2

Data Sheet

Rev. 0 | Page 16 of 20

THEORY OF OPERATION

The ADA4077-2 is the sixth generation of the Analog Devices, Inc.,

industry-standard OP07 amplifier family. The ADA4077-2 is a

high precision, low noise operational amplifier with a combination

of extremely low offset voltage and very low input bias currents.

Unlike JFET amplifiers, the low bias and offset currents are

relatively insensitive to ambient temperatures, even up to 125°C.

The Analog Devices proprietary process technology and linear

design expertise have produced a high voltage amplifier with

superior performance to the OP07, OP77, OP177, and OP1177

in tiny, 8-lead SOIC and 8-lead MSOP packages. Despite its

small size, the ADA4077-2 offers numerous improvements,

including low wideband noise, wide bandwidth, lower offset

and offset drift, lower input bias current, and complete freedom

from phase inversion.

The ADA4077-2 has a specified operating temperature range of

−40°C to +125°C with a MSL1 rating, which is as wide as any

similar device in a plastic surface-mount package. This is

increasingly important as PCB and overall system sizes

continue to shrink, causing internal system temperatures to rise.

In the ADA4077-2, power consumption is reduced by a factor

of four from the OP177, and bandwidth and slew rate have both

increased by a factor of six. The low power dissipation and very

stable performance vs. temperature also act to reduce warm-up

drift errors to insignificant levels.

Inputs are protected internally from overvoltage conditions

referenced to either supply rail. Like any high performance

amplifier, maximum performance is achieved by following

appropriate circuit and PCB guidelines.