Analog Devices Inc./Maxim Integrated MAX1087EKA-T

Overview

MAX1087EKA-T from Maxim Integrated is a 10-bit, 2-channel single-ended analog-to-digital converter (ADC) in an 8-pin SOT23 package, operating from a +3V supply. It delivers 150ksps sampling rate, ±1.0 LSB INL, 61dB SINAD, and auto-shutdown current of 0.2µA - optimized for portable temperature monitors and low-power data acquisition systems.

For engineers reviewing the MAX1087EKA-T datasheet, MAX1087EKA-T pinout, MAX1087EKA-T application, or MAX1087EKA-T equivalent, this device supports SPI/QSPI/MICROWIRE interfaces, features internal conversion clocking, true single-supply +3V operation, and 1.4µs track/hold acquisition - critical for battery-powered sensor front-ends requiring minimal PCB area and sub-200µA active current.

Technical Context

The MAX1087EKA-T implements a successive-approximation register (SAR) ADC architecture with integrated track-and-hold, supporting two single-ended analog inputs (AIN1, AIN2) referenced to GND. Conversion is initiated by CNVST edge transitions, with MSB available at DOUT after 3.7µs and full 12-bit serial output (10 data + 2 sub-bits) clocked via SCLK up to 8MHz.

It uses an internal 4MHz oscillator (±10% tolerance), eliminating external clock dependency, and employs AutoShutdown™ between conversions to reduce current to 0.2µA. Input protection diodes clamp AIN pins to VDD/GND, enabling safe operation with input voltages from GND to VDD+50mV.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (3.0mm × 1.6mm × 1.1mm), RoHS-compliant, top mark AAEV.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with ADS7822UID and MCP3202-I/P, the MAX1087EKA-T uniquely combines 150ksps speed, 0.2µA AutoShutdown, internal clock, and 8-pin SOT23 size - making it optimal for space-constrained, battery-operated systems needing rapid, autonomous conversions without MCU intervention.

Availability

MAX1087EKA-T is available at Aetrix Electronics and suitable for portable temperature monitors, flowmeters, and touch screens requiring stable component supply across extended production lifecycles.

Supply support for MAX1087EKA-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and consumer applications.

The MAX1086–MAX1089 family targets ultra-low-power, space-constrained data acquisition - delivering 10-bit accuracy with micropower consumption and minimal board footprint for battery-powered sensor systems.

FAQ

What is the maximum sampling rate supported by the MAX1087EKA-T?

The MAX1087EKA-T supports a maximum sampling rate of 150ksps. At this rate, the device draws 200µA from a +3V supply and completes conversion in 3.7µs after the CNVST falling edge. This rate is sustained with VDD = +2.7V to +3.6V and fSCLK ≤ 8MHz, enabling real-time capture of signals within its 100kHz full-linear bandwidth.

Does the MAX1087EKA-T require an external reference voltage?

Yes, the MAX1087EKA-T requires an external reference voltage applied to the REF pin. It accepts VREF from +1.0V to VDD+50mV (e.g., +2.5V typical), and a 0.1µF bypass capacitor to GND is mandatory for optimal performance. The reference directly defines the full-scale input range (0 to VREF for unipolar operation), and internal circuitry does not include a reference buffer or generator.

How are the two analog input channels selected on the MAX1087EKA-T?

Channel selection on the MAX1087EKA-T is controlled solely by CNVST timing: a single high pulse selects AIN1; a high–low–high pulse sequence selects AIN2. After power-up or shutdown, the default channel is AIN1. If fewer than 12 bits are clocked out before the next CNVST rising edge, the device toggles to the alternate channel - ensuring deterministic, software-controlled multiplexing without additional control lines.

What serial interface protocols is the MAX1087EKA-T compatible with?

The MAX1087EKA-T is fully compatible with SPI, QSPI, and MICROWIRE protocols using CPOL = 0 and CPHA = 0. It outputs 12 bits (10 data + 2 sub-bits) MSB-first on DOUT, synchronized to SCLK falling edges. QSPI allows full 10-bit read in one 12-bit transaction; SPI and MICROWIRE require two 8-bit reads to retrieve all data, with proper handling of trailing sub-bits.

What is the purpose of the two sub-bits (S1, S0) in the MAX1087EKA-T serial output?

The two sub-bits (S1, S0) in the MAX1087EKA-T's 12-bit serial output provide additional resolution beyond the primary 10-bit result, supporting enhanced dithering or averaging techniques. They are always transmitted after the 10 data bits (B9–B0) and must be clocked out to maintain synchronization - omission causes channel or mode toggling on the next CNVST cycle. These bits are not calibration coefficients but part of the SAR conversion residue.