AD8244 Datasheet

Single-Supply, Low Power, Precision FET Input Quad Buffer

Part No.:
AD8244
Manufacturer:
Analog Devices, Inc.
Page:
20 Pages
Size:
527 KB
Views:
0
Update Time:
2025-09-22 10:06:00

AD8244 DataSheet Applicable Part

Part No. In Stock Price Packaging SPQ Marking MSL Pins Temp Range Package Description
SPQ:Standard Pack Quantity;MSL:Moisture Sensitivity Level

AD8244 DataSheet PDF

AD8244 Features

  • Low power
    250 μA maximum supply current per amplifier
  • FET input
    2 pA maximum input bias current at 25°C
    Extremely high input impedance
  • Low noise
    13 nV/√Hz voltage noise at 1 kHz
    0.4 μV p-p voltage noise
    (0.1 Hz to 10 Hz)
    0.8 fA/√Hz current noise at 1 kHz
  • High dc precision
    3 μV/°C maximum offset drift
    (B grade)
  • 3 MHz bandwidth
  • Unique pinout
    No leakage from inputs to supply pins
    Provides guarding capability
  • Rail-to-rail output
  • Single-supply operation
    Input range extends to ground
  • Wide supply range
    Single-supply: 3 V to 36 V
    Dual-supply: ±1.5 V to ±18 V 
  • Available in a compact 10-lead MSOP

AD8244 Applications

  • Biopotential electrodes
  • Medical instrumentation
  • High impedance sensor conditioning
  • Filters
  • Photodiode amplifiers

AD8244 Description

The AD8244 is a precision, low power, FET input, quad unity-gain buffer that is designed to isolate very large source impedances from the rest of the signal chain. The 2 pA maximum bias current, near zero current noise, and 10 TΩ input impedance introduce almost no error, even with source impedance well into the megaohms.

Many traditional operational amplifier pinouts have a supply pin that is next to the noninverting input. A guard trace must be routed between these pins to avoid leakage currents much larger than the bias current of a FET input op amp. Guard traces can be routed between pins for large packages, such as DIP or even SOIC; however, the board area consumed by these packages is prohibitive for many modern applications. The AD8244 solves this problem with a unique pinout that physically separates the high impedance inputs from the low impedance supplies and outputs of the other buffers. This configuration simplifies guarding while reducing board space, allowing high performance and high density in the same design.

 

The AD8244 design is focused on solving problems specific to buffers. This includes close channel-to-channel matching which allows channels of the AD8244 to be used in differential signal chains with minimal error. With its low voltage noise, wide supply range, and high precision, the AD8244 is also flexible enough to provide high performance anywhere a unity-gain buffer is needed, even with low source resistance.

The AD8244 is specified over the industrial temperature range of −40°C to +85°C. It is available in a 10-lead MSOP package.

AD8244 Datasheet FAQs