18-bit sigma-delta ADC with integrated PGA and input mux
The Maxim Integrated MAX1402EAI+ is an 18-bit sigma-delta ADC that integrates a programmable gain amplifier (PGA) and an input multiplexer in a single 28-SSOP package. It accepts differential or pseudo-differential inputs through a 3- or 5-channel mux, routes them through the PGA, and converts at up to 480 samples per second via a sigma-delta architecture. The SPI data interface keeps the digital side clean — two wires for clock and data, plus a chip-select line. Typical applications include weigh scales, pressure transmitters, temperature measurement, and industrial process control loops where 18-bit resolution and low noise matter more than conversion speed.
Supply rails and temperature grade
Analog supply is a single 5 V rail; the digital supply runs from 2.7 V up to 5.25 V. The -40°C to 85°C operating range covers industrial enclosures, outdoor telecom cabinets, and engine-bay-adjacent instrumentation — not full military, but solid for factory-floor and field-transmitter duty.
480 SPS — what it means for the measurement chain
The 480 SPS maximum sampling rate is typical for a high-resolution sigma-delta converter. At 18 bits, the digital filter settles in a few conversion cycles.
Package and footprint
Housed in a 28-pin SSOP (0.209-inch body width, 5.30 mm), the MAX1402EAI+ is a surface-mount part. The supplier device package is 28-SSOP — same footprint as the industry-standard SSOP-28. No through-hole option exists for this variant; the EAI+ suffix indicates the SSOP package and ROHS3 compliance.
Lifecycle and sourcing
The MAX1402EAI+ carries an Active product status with ROHS3 compliance.