Analog Devices Inc./Maxim Integrated MAX158BEAI+

Overview

The MAX158BEAI+ from Maxim Integrated is an 8-bit, 8-channel high-speed analog-to-digital converter (ADC) with integrated track/hold, 2.5V on-chip reference, and single +5V supply operation. It delivers 2.5µs per-channel conversion time, ±1 LSB total unadjusted error, and supports Mode 0/Mode 1 microprocessor interfacing for real-time data acquisition in telecom and servo control systems.

For engineers reviewing the MAX158BEAI+ datasheet, MAX158BEAI+ pinout, MAX158BEAI+ application, or MAX158BEAI+ equivalent, this page provides verified technical context, package-validated pin functions, confirmed accuracy specs, interface timing constraints, and real-world use cases - all specific to the MAX158BEAI+ SSOP-28 variant with –40°C to +85°C temperature range and ±1 LSB error grade.

Technical Context

The MAX158BEAI+ employs a half-flash architecture with two 4-bit flash ADC sections and an internal DAC to generate 8-bit results using 31 comparators. Its analog input path includes a built-in track/hold, eliminating external components while supporting 0V to +5V input range with 45pF input capacitance and ±3µA input current.

Digital interface relies solely on CS and RD signals, enabling two operational modes: Mode 0 (WAIT-state compatible, INT-driven read) and Mode 1 (non-WAIT, pipelined read). Timing is tightly controlled - tCRD = 2.0µs typ, tRDY delay = 30ns min, and tACC1 = 1.6µs - with open-drain RDY and active-low INT outputs for processor synchronization.

Key Specifications

Pinout & Package

MAX158BEAI+ is housed in a 28-pin Shrink Small-Outline Package (SSOP) with 0.65mm lead pitch, 5.20mm × 10.07mm body dimensions, and moisture sensitivity level (MSL) 3. Pin functions are validated per Maxim's official pin description table for MAX158 (SSOP-28).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit, multi-channel ADC applications.

Compared with MAX158BCAI+, the MAX158BEAI+ trades ±1/2 LSB accuracy for guaranteed –40°C to +85°C operation - critical for outdoor telecom or factory-floor deployments. Against ADS7822U, it offers 4× channel density, integrated reference, and track/hold - reducing system-level BOM and layout complexity by eliminating ≥5 external components.

Availability

MAX158BEAI+ is available at Aetrix Electronics and suitable for telecommunications infrastructure, industrial servo control, digital signal processing front-ends, and audio instrumentation requiring stable component supply across extended temperature ranges.

Supply support for MAX158BEAI+ 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, automotive, and communications applications.

The MAX154/MAX158 product line delivers high-speed, multi-channel data acquisition solutions with integrated references and track/hold - targeting real-time signal monitoring where board space, power, and external component count must be minimized.

FAQ

What is the operating temperature range for the MAX158BEAI+?

The MAX158BEAI+ is rated for –40°C to +85°C operation, making it suitable for industrial and extended-environment applications. This specification is confirmed in the Ordering Information table on page 11 of the official datasheet, where "BE" denotes the –40°C to +85°C grade and "AI" specifies the 28-pin SSOP package. The device maintains ±1 LSB total unadjusted error across this full range.

Does the MAX158BEAI+ require an external clock signal?

No, the MAX158BEAI+ does not require an external clock. Its conversion timing is fully self-contained using internal generators synchronized to CS and RD control edges. This is explicitly stated in the Features section ("No External Clock") and verified in the Detailed Description, which describes the half-flash architecture's internal timing control - eliminating clock routing, jitter sensitivity, and external oscillator BOM cost.

How many analog input channels does the MAX158BEAI+ support?

MAX158BEAI+ supports eight single-ended analog input channels (AIN1 through AIN8), selectable via the 3-bit address bus (A0, A1, A2). This is distinct from the 4-channel MAX154 family and is confirmed in the General Description, Pin Configurations diagram for MAX158, and Applications list - all specifying "eight analog input channels" as a core differentiator of the MAX158 series.

What is the function of the RDY pin on the MAX158BEAI+?

The RDY pin on the MAX158BEAI+ is an open-drain ready signal used to interface with a microprocessor's WAIT or READY input. It goes low on the falling edge of CS and transitions to high-impedance at the end of conversion - indicating valid data on DB0–DB7. As noted in the Digital Interface section, RDY requires an external pull-up resistor if used, and may be omitted entirely if the host processor uses polling or interrupt-driven access instead.

Can the MAX158BEAI+ operate with a reference voltage other than its internal 2.5V?

Yes, the MAX158BEAI+ supports external reference configurations via VREF+ and VREF– pins. The internal 2.5V REF OUT can be disabled by connecting VREF+ to an external source (up to VDD) and VREF– to GND or another reference point. Figure 8b and Figure 8c in the datasheet confirm operation with power-supply-derived or bipolar references - enabling flexible full-scale ranges from 1V to 5V while maintaining 8-bit resolution and ±1 LSB accuracy.