LF398N - Precision Sample and Hold Amplifier in DIP8 Package

Features

  • 4µs Typical Acquisition Time
  • Guaranteed 0.01% Max. Gain Error
  • 2mV Typ. Offset Voltage
  • 2.5mV Max. Hold Step
  • Very Low Feedthrough 80dB Min.
  • High Input Impedance Under All Conditions
  • Logic Inputs Compatible with All Logic Families
  • DIP8 Package
  • For SOP8 Package, see LF398S
  • Metal Can and Ceramic Package Versions of this part are Obsolete: LF198AH, LF198H, LF398AH, LF398H, LF398J8. The LF398AN8 is Obsolete.

Typical Application

LF398N Typical Application
LF398N Typical Application

Description

Metal Can and Ceramic Package Versions of this part are Obsolete: LF198AH, LF198H, LF398AH, LF398H, LF398J8.  The LF398AN8 is Obsolete.

The LF398 is a precision sample and hold amplifier which uses a combination of bipolar and junction FET transistors to provide precision, high speed, and long hold times. A typical offset voltage of 2mV and gain error of 0.004% allow this sample and hold amplifier to be used in 12-bit systems. Dynamic performance canbe optimized by proper selection of the external hold capacitor. Acquisition times can be as low as 4µs for small capacitors while hold step and droop errors can be held below 0.1mV and 30µV/sec respectively when using larger capacitors.The LF398 is fixed at unity gain with 10 ohms input impedance independent of sample/hold mode. The logic inputs are high impedence differential to allow easy interfacing to any logic family without ground loop problems. A separate offset adjust pin can be used to zero the offset voltage in either the sample or hold mode. Additionally, the hold capacitor can be driven with an external signal to provide precision level shifting or "differencing" operation. The device will operate over a wide supply voltage range from ±5V to ±18V with very little change in performance, and key parameters are specified over this full supply range.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LF398N8#PBF N-8 N C 05-08-1510 (N8) Yes


Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LF398N8#PBF N-8 C $2.35 $1.60 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Applications

  • 12-Bit Data Acquisition Systems
  • Ramp Generators
  • Analog Switches
  • Staircase Generators
  • Sample and Difference Circuits

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

Technical Support