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

Active: In Production.

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.


Using the MAX11200 family of ADCs and the MAX1403 ADC in platinum resistance temperature detectors (PRTD) applications.

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