Analog Devices Inc./Maxim Integrated MAX159BCUA

Overview

MAX159BCUA from Maxim Integrated is a 10-bit pseudo-differential successive-approximation ADC with 108ksps sampling rate, single +2.7V to +5.25V supply operation, SPI/QSPI/MICROWIRE-compatible 3-wire serial interface, and internal track/hold - designed for low-power portable data logging and isolated data acquisition systems.

For engineers reviewing the MAX159BCUA datasheet, MAX159BCUA pinout, MAX159BCUA application, or MAX159BCUA equivalent, this page delivers verified electrical specs (±0.5 LSB INL, 66 dB SINAD, 2.5 µs wake-up), package mapping (8-pin µMAX), true pin functions, and two validated alternative parts with documented functional and application differences.

Technical Context

The MAX159BCUA implements a SAR architecture with integrated track/hold, where CH+ and CH− form a pseudo-differential input pair: only CH+ is sampled while CH− must remain stable within ±0.1 LSB relative to GND during conversion. Acquisition time is 2.5 µs with internal clock mode enabled.

It supports dual clock modes: external clock (100 kHz–2.17 MHz) for deterministic timing and internal laser-trimmed oscillator (≈2 MHz) for flexible microprocessor interfacing. The 3-wire serial interface outputs a 16-bit frame including EOC bit, channel ID, 10-bit data (MSB-first), and two sub-LSB bits.

Key Specifications

Pinout & Package

MAX159BCUA is housed in an 8-pin µMAX package (3.0 mm × 3.0 mm, 0.8 mm height, exposed pad), compatible with standard SOIC-8 footprints but with reduced footprint and thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131AUT+, the MAX159BCUA offers unique value in ultra-low shutdown current (<0.2 µA), guaranteed QSPI/MICROWIRE compatibility, and proven µMAX footprint reuse in space-constrained legacy designs - making it optimal for battery longevity and controller-agnostic integration.

Availability

MAX159BCUA is available at Aetrix Electronics and suitable for battery-powered data loggers, isolated sensor interfaces, portable medical monitors, and process-control analog inputs requiring stable component supply with long-term manufacturability.

Supply support for MAX159BCUA 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 communications applications.

The MAX157/MAX159 family was engineered for low-power, space-constrained data acquisition - delivering 10-bit accuracy with µMAX packaging, single-supply operation, and robust serial interface compatibility.

FAQ

What is the operating temperature range for MAX159BCUA?

The MAX159BCUA is rated for 0°C to +70°C ambient operation, as indicated by the 'C' suffix in its ordering code. This commercial-grade temperature range is validated across all electrical specifications including ±0.5 LSB INL, 66 dB SINAD, and 2.5 µs wake-up time - ensuring reliable performance in indoor portable equipment and non-extreme industrial environments.

Does MAX159BCUA require an external reference voltage?

Yes, MAX159BCUA requires an external reference voltage applied to the REF pin. It supports reference voltages from 0 V to (VDD + 50 mV), with 2.5 V being the typical value. The device specifies a minimum 18 kΩ DC input resistance at REF and requires the reference source to deliver 250 µA with ≤10 Ω output impedance - a standard 2.5 V precision reference IC (e.g., REF02, MAX6126) meets this requirement.

How does the pseudo-differential input of MAX159BCUA differ from true differential input?

The MAX159BCUA's pseudo-differential input samples only CH+ while treating CH− as a stable reference node (not actively sampled). CH− must remain within ±0.1 LSB of GND during conversion - achieved by bypassing CH− to GND with a 0.1 µF capacitor. Unlike true differential ADCs, it does not reject common-mode signals on CH−, but simplifies sensor interfacing compared to fully differential architectures.

Can MAX159BCUA operate with a 3.3 V supply and 2.5 V reference simultaneously?

Yes, MAX159BCUA supports mixed-supply operation: VDD = 3.3 V and REF = 2.5 V is explicitly validated in the datasheet's Electrical Characteristics table. At this condition, full-scale input range is 0 V to 2.5 V, INL remains ±0.5 LSB, and supply current is 0.9 mA at 108 ksps - enabling direct interface with 3.3 V microcontrollers while maintaining precision defined by the stable 2.5 V reference.

What is the function of the CS/SHDN pin on MAX159BCUA?

The CS/SHDN pin on MAX159BCUA serves dual roles: as an active-low chip-select input (pull low to enable serial communication and initiate conversion) and as an active-high shutdown control (pull high to reduce supply current to <0.2 µA). Its state at the falling edge of CS/SHDN also selects clock mode - high = internal clock, low = external clock - making it central to both power management and interface configuration.