Analog Devices Inc./Maxim Integrated MAX122BEWG+

Overview

MAX122BEWG+ from Maxim Integrated is a 12-bit, 333ksps BiCMOS sampling analog-to-digital converter with integrated track/hold and -5V buried-zener reference, designed for high-speed bipolar data acquisition in ±5V input systems. It operates from -40°C to +85°C, accepts 0.1–5MHz TTL-compatible clocks, and delivers 69dB SINAD and -75dB THD at 50kHz input.

For engineers reviewing the MAX122BEWG+ datasheet, MAX122BEWG+ pinout, MAX122BEWG+ application, or MAX122BEWG+ equivalent, this page provides verified timing behavior, bipolar two's-complement output format, FIFO-compatible bus interface, and validated thermal drift (±25ppm/°C) and acquisition time (350ns) - all critical for spectrum analysis, telecom processing, and industrial data logging designs.

Technical Context

The MAX122BEWG+ implements successive approximation architecture with on-chip track/hold, enabling fixed 2.6µs conversion time across its full -40°C to +85°C operating range. Its internal -5V reference features ±25ppm/°C drift and requires 22µF || 0.1µF bypassing at VREF to AGND.

It supports five microprocessor interface modes (including continuous-conversion mode with BUSY output), uses three-state TTL/CMOS-compatible 12-bit parallel outputs (D11–D0), and accepts asynchronous control via CONVST, RD, and CS with no wait states required for most µPs.

Key Specifications

Pinout & Package

MAX122BEWG+ is housed in a 24-pin wide SO (Small Outline) package with RoHS-compliant lead-free finish (+ suffix). Pin functions are electrically identical to MAX120/MAX122 family and validated per Maxim's official pin description.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7800U and MAX125CEAX+, the MAX122BEWG+ offers optimal balance of integration (on-chip ±5V reference, track/hold), industrial temperature rating, and 333ksps throughput - reducing BOM count and layout complexity for single-channel, bipolar, high-fidelity acquisition.

Availability

MAX122BEWG+ is available at Aetrix Electronics and suitable for spectrum analysis equipment, telecom channel monitors, and industrial data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX122BEWG+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing markets.

The MAX120/MAX122 product line was engineered for high-speed, precision data acquisition in space-constrained systems - integrating reference, track/hold, and µP interface to minimize external components in real-time signal processing applications.

FAQ

What is the maximum clock frequency supported by MAX122BEWG+?

The MAX122BEWG+ supports a maximum clock frequency of 5MHz, as specified in its Electrical Characteristics table under "Clock Frequency" for the MAX122 variant. This limit ensures reliable 2.6µs conversion time and stable operation across the full -40°C to +85°C temperature range. Exceeding 5MHz may cause timing violations or incomplete conversions. The MAX122BEWG+ clock input (CLKIN) is TTL/CMOS compatible and must meet rise/fall time specifications per Maxim's timing diagrams.

Does MAX122BEWG+ require external components for basic operation?

Yes, the MAX122BEWG+ requires external decoupling capacitors: 0.1µF and 10µF on VDD to AGND, and 22µF || 0.1µF on VREF to AGND. These are mandatory for stable reference performance and noise suppression. No external track/hold capacitor or op-amp driver is needed due to its integrated design. All logic interfaces are TTL/CMOS compatible, eliminating level-shifters in standard 5V systems.

How does the MODE pin configure MAX122BEWG+ behavior?

The MODE pin on MAX122BEWG+ configures the INT/BUSY output function and operating mode: tied to VDD enables interrupt output (active-low pulse on conversion completion); left open or tied to DGND configures it as a busy flag (low during conversion, high when data is ready). This pin also determines whether continuous-conversion mode activates - MODE = DGND enables it when CONVST, RD, and CS are all low.

What is the guaranteed integral nonlinearity (INL) specification for MAX122BEWG+?

The MAX122BEWG+ has a guaranteed integral nonlinearity (INL) of ±1 LSB over its full operating temperature range (-40°C to +85°C), as documented in the Ordering Information table for MAX122BC/BE variants. This specification ensures monotonicity and predictable transfer function behavior in closed-loop control and precision measurement applications where code-to-code linearity is critical.

Can MAX122BEWG+ interface directly with a FIFO buffer without a microprocessor?

Yes, MAX122BEWG+ supports direct FIFO interfacing in stand-alone mode (MODE open, RD = CS = DGND) and continuous-conversion mode (MODE = DGND, CONVST = RD = CS = DGND). In both modes, the INT/BUSY output signals data readiness, and three-state outputs drive the FIFO write port without µP intervention - enabling high-throughput streaming in systems like spectrum analyzers or real-time data recorders.