Analog Devices Inc./Maxim Integrated MAX1241CESA+T

Overview

MAX1241CESA+T from Maxim Integrated is a low-power, 12-bit successive-approximation analog-to-digital converter (ADC) with 73ksps throughput, 7.5µs conversion time, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface. It operates from a single +2.7V to +5.25V supply, requires an external reference (0V to VREF input range), and targets space-constrained, battery-powered data acquisition systems.

For engineers reviewing the MAX1241CESA+T datasheet, MAX1241CESA+T pinout, MAX1241CESA+T application, or MAX1241CESA+T equivalent, this page delivers verified electrical specs, validated SO-8 package mapping, confirmed shutdown behavior (2µA), real-world timing constraints (tACQ = 1.5µs, tCONV = 7.5µs), and two rigorously cross-checked alternative ADCs for 12-bit, serial-output, low-voltage embedded sensing.

Technical Context

The MAX1241CESA+T implements a track/hold stage followed by a 12-bit SAR core, with internal clock generation and unipolar binary output. Its analog input accepts 0V to VREF signals, where VREF is externally supplied and must be stable within ±0.3V of GND and VDD.

Control logic responds to CS falling edge to initiate conversion and uses SCLK (up to 2.1MHz) to shift out 13-bit serial frames: one leading EOC bit followed by 12 MSB-first data bits. Shutdown is managed via the SHDN pin, enabling <2µA quiescent current with 4µs wake-up when external reference is present.

Key Specifications

Pinout & Package

MAX1241CESA+T is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and lead-free (+ suffix), rated for -40°C to +85°C operation (E-grade).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with MAX1241CESA+T, ADS7822U trades 2µA shutdown capability for 2.7× higher throughput and no dedicated SHDN control, while AD7476AARMZ offers 170× lower shutdown current but demands stricter reference regulation and provides no native track/hold acquisition timing guarantee.

Availability

MAX1241CESA+T is available at Aetrix Electronics and suitable for battery-powered data loggers, isolated industrial sensors, portable medical instrumentation, and process control transmitters requiring stable component supply across extended production lifecycles.

Supply support for MAX1241CESA+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 demanding industrial, medical, and communications applications.

The MAX1240/MAX1241 family delivers low-power, small-footprint 12-bit ADCs optimized for remote sensing and portable instrumentation where supply voltage flexibility, serial interface simplicity, and guaranteed DC accuracy are essential.

FAQ

What is the reference voltage requirement for MAX1241CESA+T?

The MAX1241CESA+T requires an external reference voltage applied to the REF pin, ranging from +1.0V to VDD (max +5.25V). It does not include an internal reference. The reference must provide ≤10Ω output impedance and sustain up to 250µA load during conversion. For optimal performance, bypass REF with ≥0.1µF ceramic capacitor placed close to the pin.

Does MAX1241CESA+T support SPI, QSPI, and MICROWIRE interfaces simultaneously?

Yes, the MAX1241CESA+T serial interface is electrically and protocol-compatible with SPI (CPOL=0, CPHA=0), QSPI, and MICROWIRE standards. It uses a 3-wire configuration (SCLK, CS, DOUT) with MSB-first unipolar output and a leading end-of-conversion (EOC) bit. No mode pins or configuration registers are needed-compatibility is inherent in timing and signaling behavior.

What is the minimum acquisition time for MAX1241CESA+T, and how does source impedance affect it?

The guaranteed minimum acquisition time (tACQ) for MAX1241CESA+T is 1.5µs. However, actual acquisition time scales with source impedance: tACQ = 9 × (RS + 9kΩ) × 16pF. For RS < 1kΩ, tACQ remains ~1.5µs; above that, longer intervals between conversions are required. A 0.01µF capacitor at AIN mitigates high-RS effects but reduces input bandwidth.

Can MAX1241CESA+T operate from a 5V supply while using a 2.5V reference?

Yes, MAX1241CESA+T supports VDD = +2.7V to +5.25V independently of VREF. With VDD = 5V and VREF = 2.5V, the device digitizes 0V to 2.5V analog inputs at 12-bit resolution (1 LSB = 610µV). This configuration is explicitly validated in the datasheet's Electrical Characteristics table under "DC Accuracy" conditions.

How does the SHDN pin function on MAX1241CESA+T, and what is its leakage impact?

On MAX1241CESA+T, SHDN is a three-level input: pulled low → shutdown (<2µA IDD); floated or pulled high → active mode. Unlike the MAX1240, SHDN has no effect on reference selection. SHDN input leakage is ±0.01µA (typical) at 25°C, ensuring negligible impact on external reference divider networks or high-impedance biasing circuits.