Analog Devices Inc./Maxim Integrated MAX1243ACSA

Overview

MAX1243ACSA from Maxim Integrated is a low-power, 10-bit successive-approximation analog-to-digital converter (SAR ADC) 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 integral nonlinearity at 0°C to +70°C in SO-8 package - ideal for portable data logging and isolated sensor interfaces.

For engineers reviewing the MAX1243ACSA datasheet, MAX1243ACSA pinout, MAX1243ACSA application, or MAX1243ACSA equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options with documented differences, and supply-chain support details specific to this SO-8, commercial-grade variant.

Technical Context

The MAX1243ACSA implements a track/hold circuit with 1.5µs acquisition time and a 10-bit SAR core clocked by an internal oscillator, eliminating need for external timing components. Its 3-wire serial interface operates up to 2.1MHz with SCLK falling-edge data output, compatible with SPI (CPOL=0, CPHA=0), QSPI, and MICROWIRE protocols.

It uses an external reference applied to the REF pin (1.0V to VDD), with specified accuracy requiring ≤10Ω source impedance and ≥18kΩ DC input resistance. Shutdown mode reduces supply current to 2µA, and wake-up time is ~4µs when external reference remains powered.

Key Specifications

Pinout & Package

MAX1243ACSA is housed in an 8-pin SO (Small Outline) package, RoHS-compliant, with gull-wing leads and standard JEDEC MS-012AC outline (S8+5). Thermal performance rated at 5.88mW/°C derating above +70°C, max continuous dissipation 471mW at TA = +70°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1243BCSA+, the MAX1243ACSA offers tighter ±0.5 LSB INL for precision measurement; compared with ADS7822U, it provides external reference support and lower shutdown current, enabling flexible ratiometric designs and ultra-low-power sleep modes.

Availability

MAX1243ACSA is available at Aetrix Electronics and suitable for portable data logging, process control monitoring, and test equipment requiring stable component supply across commercial temperature range (0°C to +70°C) and long-term production continuity.

Supply support for MAX1243ACSA 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 high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX1242/MAX1243 product line was designed for low-power, space-constrained data acquisition systems requiring high DC accuracy and simple serial interfacing - particularly where external reference control and minimal supply current are critical.

FAQ

What is the reference voltage requirement for MAX1243ACSA?

The MAX1243ACSA requires an external reference voltage applied to the REF pin, ranging from 1.0V to VDD. For optimal accuracy, the reference must have ≤10Ω output impedance and be bypassed with ≥0.1µF ceramic capacitor. Unlike the MAX1242, the MAX1243ACSA has no internal reference - so external REF is mandatory for all conversions.

Does MAX1243ACSA support SPI interface timing?

Yes, the MAX1243ACSA supports standard SPI timing with CPOL = 0 and CPHA = 0. Conversion starts on CS falling edge; DOUT goes low during conversion and rises to signal end-of-conversion (EOC); data shifts out MSB-first on SCLK falling edge. Two byte reads (11 total clock cycles) retrieve the 10-bit result plus status bits.

What is the maximum sampling rate of MAX1243ACSA?

The MAX1243ACSA achieves a maximum sampling rate of 73ksps, limited by its 7.5µs conversion time and minimum CS pulse width (240ns). At this rate, power consumption is 3mW with VDD = 3V. Lower throughput rates reduce average current - e.g., 1ksps draws only 66µW.

How does shutdown mode work on MAX1243ACSA?

Pulling SHDN low places MAX1243ACSA into shutdown mode, reducing supply current to 2µA (VDD ≤ 3.6V). The device wakes up in ~4µs if the external reference remains powered; no internal reference calibration is needed. SHDN high or open enables normal operation - unlike MAX1242, SHDN state does not affect reference selection.

Is MAX1243ACSA pin-compatible with MAX1242 variants?

Yes, MAX1243ACSA is pin-compatible with MAX1242ACSA and other SO-8 variants in the MAX1242/MAX1243 family. Same 8-pin SO package, identical pinout (VDD, AIN, SHDN, REF, GND, DOUT, CS, SCLK), and shared timing specifications allow hardware reuse - though MAX1242 includes internal 2.5V reference while MAX1243ACSA requires external REF.