The MAX1402 low-power, multichannel, serial-outputanalog-to-digital converter (ADC) features matched200µA current sources for sensor excitation. This ADCuses a sigma-delta modulator with a digital decimationfilter to achieve 16-bit accuracy. The digital filter’s user-selectabledecimation factor allows the conversion resolutionto be reduced in exchange for a higher outputdata rate. True 16-bit performance is achieved at anoutput data rate of up to 480sps. In addition, the modulatorsampling frequency may be optimized for eitherlowest power dissipation or highest throughput rate.The MAX1402 operates from a +5V supply.

This device offers three fully differential input channelsthat may be independently programmed with a gainbetween +1V/V and +128V/V. Furthermore, it can compensatean input-referred DC offset up to 117% of theselected full-scale range. These three differential channelsmay also be configured to operate as five pseudo-differentialinput channels. Two additional, fullydifferential system-calibration channels are provided forgain and offset error correction.

The MAX1402 may be configured to sequentially scan allsignal inputs and provide the results via the serial interfacewith minimum communications overhead. Whenused with a 2.4576MHz or 1.024MHz master clock, thedigital decimation filter can be programmed to producezeros in its frequency response at the line frequency andassociated harmonics, ensuring excellent line rejectionwithout the need for further post-filtering.

The MAX1402 is available in a 28-pin SSOP package.