The Intersil HI7191 is a monolithic instrumentation, sigma delta A/D converter which operates from ±5V supplies. Both the signal and reference inputs are fully differential for maximum flexibility and performance. An internal Programmable Gain Instrumentation Amplifier (PGIA) provides input gains from 1 to 128 eliminating the need for external pre-amplifiers. The on-demand converter auto-calibrate function is capable of removing offset and gain errors existing in external and internal circuitry. The on-board user programmable digital filter provides over 120dB of 60/50Hz noise rejection and allows fine tuning of resolution and conversion speed over a wide dynamic range. The HI7190 and HI7191 are functionally the same device, but the HI7190 has tighter linearity specs. The HI7191 contains a serial I/O port and is compatible with most synchronous transfer formats including both the Motorola 6805/11 series SPI and Intel 8051 series SSR protocols. A sophisticated set of commands gives the user control over calibration, PGIA gain, device selection, standby mode, and several other features. The On-chip Calibration Registers allow the user to read and write calibration data.


  • 20-Bit Resolution with No Missing Code
  • 0.0015% Integral Non-Linearity (Typ)
  • 20mV to ±2.5V Full Scale Input Ranges
  • Internal PGIA with Gains of 1 to 128
  • Serial Data I/O Interface, SPI Compatible
  • Differential Analog and Reference Inputs
  • Internal or System Calibration
  • 120dB Rejection of 60/50Hz Line Noise
  • Settling Time of 4 Conversions (Max) for a Step Input
  • Pb-Free Plus Anneal Available (RoHS Compliant)


  • Process Control and Measurement
  • Industrial Weight Scales
  • Part Counting Scales
  • Laboratory Instrumentation
  • Seismic Monitoring
  • Magnetic Field Monitoring

Product Options

Orderable Part ID Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active SOICW Tube 760
Active SOICW Reel 1000

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
HI7191 Datasheet Datasheet PDF 1.24 MB
Application Notes & White Papers
AN9675: A Tutorial in Coherent and Windowed Sampling with A/D Converters Application Note PDF 503 KB
AN002: Principles of Data Acquisition and Conversion Application Note PDF 1.08 MB
AN9601: Using the HI7190 with Single +5V Supply Application Note PDF 262 KB
AN9527: Interfacing the HI7190 to a Microcontroller Application Note PDF 353 KB
AN9532: Using the HI7190 in a Multiplexed System Application Note PDF 281 KB
AN9510: Basic Analog for Digital Designers Application Note PDF 508 KB
AN9705: A Theoretical View of Coherent Sampling Application Note PDF 287 KB
PCN12094 - Alternate Manufacturing Site for Assembly of the Listed Intersil Packaged Products - Amkor Technology, Philippines (ATP) Product Change Notice PDF 98 KB
PCN12086 - Alternate Manufacturing Site for Assembly of the Listed Intersil PDIP Packaged Products -Amkor Technology, Philippines (ATP) Product Change Notice PDF 86 KB
TB348: HI7190, HI7191 Negative Full Scale Error Versus Conversion Frequency Other PDF 255 KB
TB331: Using the HI7190 Serial Interface Other PDF 270 KB
TB329: Sigma-Delta Calibration Technique Other PDF 275 KB