HI7190

Features:

• 22-Bit Resolution with No Missing Code
• 0.0007% 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




Application

• Process Control and Measurement
• Industrial Weight Scales
• Part Counting Scales
• Laboratory Instrumentation
• Seismic Monitoring
• Magnetic Field Monitoring
• Additional Reference Literature
- TB348 "HI7190/1 Negative Full Scale Error vs Conversion Frequency"
- AN9504 "A Brief Intro to Sigma Delta Conversion"
- TB329 "Harris Sigma Delta Calibration Technique"
- AN9505 "Using the HI7190 Evaluation Kit"
- TB331 "Using the HI7190 Serial Interface"
- AN9527 "Interfacing HI7190 to a Microcontroller"
- AN9532 "Using HI7190 in a Multiplexed System"
- AN9601 "Using HI7190 with a Single +5V Supply"




Pinout






Specifications

Supply Voltage
AVDD to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+5.5V
AV_SS to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. -5.5V
DVDD to DGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5.5V
DGND to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ±0.3V
Analog Input Pins . . . . . . . . . . . . . . . . . . . . . . . . . .. AV_SS to AV_DD
Digital Input, Output and I/O Pins . . . . . . . . . . . . . DGND to DV_DD
ESD Tolerance (No Damage)
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 500V
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +100V
Charged Device Model . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 1000V




Description

The Harris HI7190 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 HI7190 ondemand 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 so all discussion will refer to the HI7190 for simplicity.

The HI7190 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.