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+3V, 18-Bit, Low-Power, Multichannel, Oversampling (Sigma-Delta) ADC

Best Linearity for +3V, 18-Bit Sigma Delta

Product Details

The MAX1403 18-bit, low-power, multichannel, serial-output analog-to-digital converter (ADC) features matched 200µA current sources for sensor excitation. This ADC uses a sigma-delta modulator with a digital decimation filter to achieve 16-bit accuracy. The digital filter's user-selectable decimation factor allows the conversion resolution to be reduced in exchange for a higher output data rate. True 16-bit performance is achieved at an output data rate of up to 480sps. In addition, the modulator sampling frequency may be optimized for either lowest power dissipation or highest throughput rate. The MAX1403 operates from +3V.

This device offers three fully differential input channels that may be independently programmed with a gain between +1V/V and +128V/V. Furthermore, it can compensate an input-referred DC offset up to 117% of the selected full-scale range. These three differential channels may also be configured to operate as five pseudo-differential input channels. Two additional, fully differential system-calibration channels are provided for gain and offset error correction.

The MAX1403 can be configured to sequentially scan all signal inputs and provide the results via the serial interface with minimum communications overhead. When used with a 2.4576MHz or 1.024MHz master clock, the digital decimation filter can be programmed to produce zeros in its frequency response at the line frequency and associated harmonics, ensuring excellent line rejection without the need for further postfiltering.

The MAX1403 is available in a 28-pin SSOP package.

Key Features

  • 18-Bit Resolution, Sigma-Delta ADC
  • 16-Bit Accuracy with No Missing Codes to 480sps
  • Matched On-Board Current Sources (200µA) for Sensor Excitation
  • Low Quiescent Current
    • 250µA (operating mode)
    • 2µA (power-down mode)
  • 3 Fully Differential or 5 Pseudo-Differential Signal Input Channels
  • 2 Additional, Fully Differential Calibration Channels/Auxiliary Input Channels
  • Programmable Gain and Offset
  • Fully Differential Reference Inputs
  • Converts Continuously or On Command
  • Automatic Channel Scanning and Continuous Data Output Mode
  • Operates with Analog and Digital Supplies from +2.7V to +3.6V
  • SPI™/QSPI™-Compatible 3-Wire Serial Interface
  • 28-Pin SSOP Package

Applications/Uses

  • Loop-Powered Systems
  • Portable Industrial Instruments
  • Portable Weight Scales
  • Pressure Sensors and Transducers
Parametric specs for Precision ADCs (< 5Msps)
Resolution (bits) (ADC) 18
# Input Channels 5
Conv. Rate (ksps) (max) 4.8
Data Bus SPI
ADC Architecture Sigma-Delta
Diff/S.E. Input Diff. Only
External VREF (V) (min) 0
External VREF (V) (max) 1.25
Unipolar VIN (V) (max) 1.25
Bipolar VIN (±V) (max) 1.25
INL (±LSB) 3
Package/Pins SSOP/28
Budgetary
Price (See Notes)
$12.75 @1k
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Simplified Block Diagram

MAX1403: Functional Diagram MAX1403: Functional Diagram Zoom icon

Design & Development

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Description

The MAX1403 evaluation system (EV system) is a complete, multichannel data-acquisition system consisting of a MAX1403 evaluation kit (EV kit) and a Maxim 68HC11 microcontroller (µC) module. The MAX1403 is a low-power, multichannel, serial-output analog-to-digital converter (ADC). Windows® 95/98-compatible software provides a handy user interface to exercise the MAX1403's features. Source code in C++ and 68HC11 assembly language is provided for the low-level portion of the software.

Order the EV system for comprehensive evaluation of the MAX1403 using a personal computer. Order only the EV kit if the 68HC11 µC module has already been purchased with a previous Maxim EV system or for custom use in other µC-based systems.

The MAX1403 EV kit and EV system can also be used to evaluate the MAX1401. Simply order a free sample of the MAX1401CAI along with the MAX1403EVKIT.

MAX1403 Stand-Alone EV Kit
The MAX1403 EV kit provides a proven PC board layout to facilitate evaluation of the MAX1403 with user-provided software and hardware. It must be interfaced to appropriate timing signals for proper operation. Refer to the MAX1403 data sheet for timing requirements.

MAX1403 EV System
The MAX1403 EV system operates from a user-supplied +5V to +12V DC power supply.

View Details

Features

  • Easy to Configure
  • Collects Up to 8192 Samples at Full Speed
  • Complete Evaluation System
  • Proven PC Board Layout
  • Fully Assembled and Tested

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Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

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Parameters

Parametric specs for Precision ADCs (<u><</u> 5Msps)
Resolution (bits) (ADC) 18
# Input Channels 5
Conv. Rate (ksps) (max) 4.8
Data Bus SPI
ADC Architecture Sigma-Delta
Diff/S.E. Input Diff. Only
External VREF (V) (min) 0
External VREF (V) (max) 1.25
Unipolar VIN (V) (max) 1.25
Bipolar VIN (±V) (max) 1.25
INL (±LSB) 3
Package/Pins SSOP/28
Budgetary
Price (See Notes)
$12.75 @1k

Key Features

  • 18-Bit Resolution, Sigma-Delta ADC
  • 16-Bit Accuracy with No Missing Codes to 480sps
  • Matched On-Board Current Sources (200µA) for Sensor Excitation
  • Low Quiescent Current
    • 250µA (operating mode)
    • 2µA (power-down mode)
  • 3 Fully Differential or 5 Pseudo-Differential Signal Input Channels
  • 2 Additional, Fully Differential Calibration Channels/Auxiliary Input Channels
  • Programmable Gain and Offset
  • Fully Differential Reference Inputs
  • Converts Continuously or On Command
  • Automatic Channel Scanning and Continuous Data Output Mode
  • Operates with Analog and Digital Supplies from +2.7V to +3.6V
  • SPI™/QSPI™-Compatible 3-Wire Serial Interface
  • 28-Pin SSOP Package

Applications/Uses

  • Loop-Powered Systems
  • Portable Industrial Instruments
  • Portable Weight Scales
  • Pressure Sensors and Transducers

Description

The MAX1403 18-bit, low-power, multichannel, serial-output analog-to-digital converter (ADC) features matched 200µA current sources for sensor excitation. This ADC uses a sigma-delta modulator with a digital decimation filter to achieve 16-bit accuracy. The digital filter's user-selectable decimation factor allows the conversion resolution to be reduced in exchange for a higher output data rate. True 16-bit performance is achieved at an output data rate of up to 480sps. In addition, the modulator sampling frequency may be optimized for either lowest power dissipation or highest throughput rate. The MAX1403 operates from +3V.

This device offers three fully differential input channels that may be independently programmed with a gain between +1V/V and +128V/V. Furthermore, it can compensate an input-referred DC offset up to 117% of the selected full-scale range. These three differential channels may also be configured to operate as five pseudo-differential input channels. Two additional, fully differential system-calibration channels are provided for gain and offset error correction.

The MAX1403 can be configured to sequentially scan all signal inputs and provide the results via the serial interface with minimum communications overhead. When used with a 2.4576MHz or 1.024MHz master clock, the digital decimation filter can be programmed to produce zeros in its frequency response at the line frequency and associated harmonics, ensuring excellent line rejection without the need for further postfiltering.

The MAX1403 is available in a 28-pin SSOP package.

Simplified Block Diagram

MAX1403: Functional Diagram MAX1403: Functional Diagram Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal