Analog Devices Inc./Maxim Integrated MAX1243AESA

Overview

MAX1243AESA from Maxim Integrated is a low-power, 10-bit successive-approximation analog-to-digital converter (SAR ADC) in an 8-pin SOIC package, operating from +2.7V to +5.25V supply, featuring 7.5µs conversion time, 73ksps throughput, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface. It requires an external reference voltage (1.0V to VDD), supports 0V to VREF input range, and delivers ±0.5 LSB INL at −40°C to +85°C.

For engineers reviewing the MAX1243AESA datasheet, MAX1243AESA pinout, MAX1243AESA application, or MAX1243AESA equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative options with documented differences, and supply-chain support details specific to this SO-8, industrial-grade variant.

Technical Context

The MAX1243AESA implements a track/hold circuit with 1.5µs acquisition time and a 10-bit SAR core clocked internally, eliminating need for external timing control during conversion. Its 3-wire serial interface uses unipolar MSB-first output format with EOC signaling via DOUT high transition, compatible with standard microcontroller I/O without protocol-specific hardware.

It operates exclusively with an external reference (1.0V to VDD), accepts analog inputs from 0V to VREF, and features a three-level SHDN pin that enables shutdown mode (<2µA) but does not control internal reference (absent in MAX1243). Power consumption scales linearly with throughput: 3mW at 73ksps (VDD = 3V), 66µW at 1ksps.

Key Specifications

Pinout & Package

MAX1243AESA is housed in an 8-pin SOIC (SO-8) package with standard 1.27mm pitch, RoHS-compliant, and thermally rated for −40°C to +85°C operation. Pin 1 is marked with a dot or bevelled corner; pin numbering follows standard SOIC convention (counterclockwise from pin 1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1243AESA, MAX1243BCSA+ trades 0.5 LSB linearity for lower unit cost while retaining identical packaging and temperature range, whereas ADS7822U offers higher resolution but sacrifices guaranteed industrial-grade linearity and multi-protocol serial compatibility.

Availability

MAX1243AESA is available at Aetrix Electronics and suitable for portable data logging, process control monitoring, and isolated data acquisition requiring stable component supply with guaranteed −40°C to +85°C performance and RoHS-compliant packaging.

Supply support for MAX1243AESA 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) is a semiconductor company specializing in precision analog, mixed-signal, and high-reliability ICs for industrial, medical, and communications applications.

The MAX1242/MAX1243 product line was designed for low-power, space-constrained data acquisition systems requiring high integration, minimal external components, and robust serial interfacing - especially where battery life and PCB area are critical.

FAQ

What is the reference voltage requirement for MAX1243AESA?

The MAX1243AESA requires an external reference voltage applied to the REF pin, ranging from 1.0V to VDD. It does not include an internal reference. The reference must have ≤10Ω output impedance and supply up to 250µA during conversion. A minimum 0.1µF ceramic capacitor is required at REF for stability. This differs fundamentally from the MAX1242AESA, which integrates a 2.5V reference.

Does MAX1243AESA support SPI, QSPI, and MICROWIRE protocols simultaneously?

Yes, MAX1243AESA's 3-wire serial interface (CS, SCLK, DOUT) is electrically and logically compatible with SPI, QSPI, and MICROWIRE standards. It uses CPOL = 0 and CPHA = 0 timing, outputs MSB-first with EOC signaled by DOUT rising edge, and requires no mode configuration - the same physical connection works across all three protocols.

What is the maximum sampling rate of MAX1243AESA and what limits it?

The MAX1243AESA achieves a maximum sampling rate of 73ksps, limited by its fixed 7.5µs conversion time and minimum CS pulse width (240ns). To sustain 73ksps, the host must complete CS assertion, data read (≥13 SCLK edges), and CS deassertion within ≤13.7µs total cycle time. Higher rates are not supported due to internal SAR timing constraints.

How does the SHDN pin function on MAX1243AESA?

On MAX1243AESA, the SHDN pin is a three-level input: pulling low places the device in shutdown mode (<2µA supply current); leaving open or pulling high enables normal operation. Unlike the MAX1242, SHDN has no effect on reference selection - MAX1243AESA always uses external reference regardless of SHDN state.

Is MAX1243AESA pin-compatible with any 12-bit upgrade options?

Yes, MAX1243AESA is pin-compatible with the 12-bit MAX1241AESA (same SO-8 package, −40°C to +85°C grade). However, software must accommodate 12-bit output format and revised timing; the pin mapping, supply, reference, and interface logic remain identical, enabling hardware reuse in resolution-upgraded designs.