Analog Devices Inc./Maxim Integrated MAX157BCUA+T

Overview

MAX157BCUA+T from Maxim Integrated is a low-power, 10-bit successive-approximation analog-to-digital converter (ADC) with two single-ended input channels, 108ksps sampling rate, ±0.5 LSB differential nonlinearity, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - designed for battery-powered instrumentation and portable data logging systems operating from +2.7V to +5.25V.

For engineers reviewing the MAX157BCUA+T datasheet, MAX157BCUA+T pinout, MAX157BCUA+T application, or MAX157BCUA+T equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-chain support details specific to the µMAX-packaged MAX157BCUA+T variant.

Technical Context

The MAX157BCUA+T implements a SAR architecture with integrated track/hold, internal clock generation (±20% tolerance at ~2MHz), and automatic power-down mode triggered by CS/SHDN high. It supports both internal clock mode (for SCLK < 100kHz or > 2.17MHz) and external clock mode (100kHz–2.17MHz), where the same SCLK drives conversion timing and data transfer.

Its analog front-end accepts 0–VREF single-ended inputs on CH0 and CH1, with channel switching controlled via CS/SHDN toggling. The device features 16pF hold capacitance, 9kΩ input resistance, and 7.4µs conversion time - enabling accurate acquisition from sources ≤4kΩ without external filtering.

Key Specifications

Pinout & Package

MAX157BCUA+T is housed in an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), thermally enhanced with exposed pad, rated for 0°C to +70°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX157BCUA+T, MAX144BCPA+ trades lower power and smaller size for 2 extra bits of resolution, while ADS7822U offers faster throughput and TI's production support but omits MICROWIRE compatibility and µMAX packaging - making MAX157BCUA+T optimal for space-constrained, ultra-low-power, multi-standard serial interface designs.

Availability

MAX157BCUA+T is available at Aetrix Electronics and suitable for battery-powered data loggers, portable medical sensors, industrial process monitoring nodes, and smart building environmental controllers requiring stable component supply across extended production lifecycles.

Supply support for MAX157BCUA+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 MAX157 belongs to Maxim's low-power serial ADC product line, engineered specifically for space- and energy-constrained systems requiring high accuracy, fast wake-up, and multi-standard serial interface flexibility in miniature packages.

FAQ

What is the operating temperature range for MAX157BCUA+T?

The MAX157BCUA+T is specified for 0°C to +70°C operation, as indicated by the 'C' suffix in the part number and confirmed in the Ordering Information table. This commercial-grade temperature range aligns with its µMAX package variant and distinguishes it from extended-range versions like MAX157AEUA (–40°C to +85°C) or MAX157AMJA (–55°C to +125°C). All electrical characteristics in the datasheet are guaranteed within this 0°C to +70°C window.

Does MAX157BCUA+T support pseudo-differential input mode?

No, MAX157BCUA+T does not support pseudo-differential input mode. It is the MAX157 variant - a 2-channel single-ended ADC - whereas pseudo-differential operation is exclusive to the MAX159 family. The MAX157BCUA+T accepts independent 0–VREF inputs on CH0 and CH1, both referenced to GND. Attempting to use CH1 as a negative input will result in incorrect conversion results, as confirmed in the Pin Description and Detailed Description sections.

What reference voltage options are compatible with MAX157BCUA+T?

MAX157BCUA+T requires an external reference voltage applied to the REF pin, supporting 0V to (VDD + 50mV) - typically 2.5V (as tested in specifications) or VDD itself. The reference must deliver ≥250µA DC load current with ≤10Ω output impedance and be bypassed with a 0.1µF capacitor placed close to the REF pin. Internal reference is not provided; using VDD as REF yields a ratiometric measurement, while a precision 2.5V reference (e.g., MAX6126) enables absolute voltage accuracy.

How does the CS/SHDN pin control channel selection on MAX157BCUA+T?

On MAX157BCUA+T, the CS/SHDN pin controls channel selection via toggling: after power-on reset, the device defaults to CH0; a falling edge on CS/SHDN initiates conversion on the current channel and automatically switches to the alternate channel (CH0 ↔ CH1) for the next conversion. To read the same channel consecutively, toggle CS/SHDN twice - once to complete the first conversion and again before the second. This behavior is intrinsic to the MAX157 architecture and is documented in the Detailed Description section.

Is MAX157BCUA+T pin-compatible with any 12-bit ADC upgrades?

Yes, the datasheet explicitly states that "pin-compatible 12-bit upgrades" are available in the MAX144/MAX145 series. Specifically, MAX144BCPA+ shares the same 8-pin DIP footprint and pinout as MAX157BCUA+T, though it uses a different package (DIP vs. µMAX) and requires layout adaptation. No µMAX-packaged 12-bit pin-compatible upgrade is listed for MAX157BCUA+T; the MAX144/MAX145 family offers functional upgrade paths but not identical package compatibility.