Analog Devices Inc./Maxim Integrated MAX1157BEUI+

Overview

MAX1157BEUI+ from Maxim Integrated is a 14-bit, 135ksps successive-approximation ADC with unipolar 0V to +10V analog input range, single +4.75V to +5.25V analog supply, and ±1LSB INL (max) DC accuracy. It features a 14-bit parallel interface, internal +4.096V reference, and AutoShutdown™ reducing current to 0.4mA at 10ksps - used in industrial I/O modules requiring high-resolution voltage monitoring.

For engineers reviewing the MAX1157BEUI+ datasheet, MAX1157BEUI+ pinout, MAX1157BEUI+ application, or MAX1157BEUI+ equivalent, key selection factors include its extended temperature range (–40°C to +85°C), TSSOP-28 package compatibility, bipolar/unipolar input flexibility across the MAX1157/MAX1159/MAX1175 family, and trade-offs between internal vs. external reference power consumption and accuracy.

Technical Context

The MAX1157BEUI+ implements a SAR architecture with integrated track-and-hold, enabling 135ksps sampling without external clocking. Its input scaler supports true 0V to +10V unipolar operation from a single +5V analog rail, while internal reference buffering eliminates need for external op-amp drive.

Control logic relies on three CS edges: first enables acquisition (R/C low), second initiates conversion, third loads data (R/C high). Power-down mode (standby vs. shutdown) is selected via R/C state during the second CS edge, directly affecting reference wake-up time (6ms vs. 12ms) and post-conversion current draw (3.7mA vs. 0.5µA).

Key Specifications

Pinout & Package

MAX1157BEUI+ is housed in a 28-pin Thin Shrink Small Outline Package (TSSOP) with 0.65mm pitch, designed for high-density PCB layouts and thermal performance in industrial enclosures.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-bit SAR ADC applications.

Compared with ADS8325IPW and AD7942BRMZ, the MAX1157BEUI+ offers integrated +4.096V reference, parallel interface for low-latency reads, and native 0–10V input support - reducing BOM count and layout complexity in industrial analog input designs.

Availability

MAX1157BEUI+ is available at Aetrix Electronics and suitable for industrial process control, precision instrumentation, and I/O modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1157BEUI+ 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 MAX1157BEUI+ belongs to Maxim's high-performance SAR ADC product line, engineered for applications demanding high DC accuracy, low power, and simplified system integration in space- and power-constrained industrial environments.

FAQ

What is the analog input voltage range supported by the MAX1157BEUI+?

The MAX1157BEUI+ supports a unipolar analog input voltage range of 0V to +10V. This is distinct from the MAX1159 (±10V) and MAX1175 (±5V) variants in the same family. The input scaler enables this full-scale range to operate from a single +5V analog supply, eliminating need for external level-shifting circuitry in 0–10V sensor interface applications.

Does the MAX1157BEUI+ include an internal voltage reference?

Yes, the MAX1157BEUI+ integrates a factory-trimmed +4.096V internal reference buffered at the REF pin. It achieves ±0.4% initial accuracy and ±35ppm/°C temperature coefficient. REFADJ allows fine adjustment or external reference selection. When using the internal reference, bypass REF with 10µF and REFADJ with 0.1µF capacitors to AGND for optimal stability.

What is the maximum sampling rate of the MAX1157BEUI+ and how is it controlled?

The MAX1157BEUI+ achieves a maximum sampling rate of 135ksps. Conversion timing is fully self-contained: the internal clock drives the SAR process, and acquisition/conversion/data-latch sequencing is controlled by three falling edges of the CS signal in combination with the R/C input state - no external clock source or timing circuitry is required.

How does AutoShutdown™ operate in the MAX1157BEUI+ and what power savings does it provide?

AutoShutdown™ in the MAX1157BEUI+ reduces total supply current to 0.4mA at 10ksps by powering down the internal reference and buffer between conversions when R/C is high during the second CS edge. At full 135ksps with internal reference, supply current is 6.2mA; in shutdown mode between conversions, it drops to 0.5µA typical - enabling significant energy savings in duty-cycled data-acquisition systems.

What package type and temperature grade does the MAX1157BEUI+ use?

The MAX1157BEUI+ is packaged in a 28-pin TSSOP (Thin Shrink Small Outline Package) and is specified for the extended industrial temperature range of –40°C to +85°C. The 'E' in the part number denotes this extended grade, distinguishing it from the commercial-grade 'C' variant (0°C to +70°C), making it suitable for deployment in harsh environmental conditions.