Analog Devices Inc./Maxim Integrated MX7821KN

Overview

MX7821KN from Maxim Integrated is a 12-bit, 1.25 MSPS successive-approximation analog-to-digital converter (ADC) with internal reference and parallel CMOS-compatible interface. It operates from a single +5V supply, features ±0.5 LSB integral nonlinearity, and is used in high-speed data acquisition systems for industrial process control.

For engineers reviewing the MX7821KN datasheet, MX7821KN pinout, MX7821KN application, or MX7821KN equivalent, key selection factors include sampling rate, INL accuracy, reference integration, parallel interface timing, and single-supply operation in real-time control loops.

Technical Context

The MX7821KN employs a successive-approximation register (SAR) architecture with a built-in 2.5V precision bandgap reference, eliminating external reference components. Its parallel 12-bit digital output interfaces directly to microcontrollers or DSPs without glue logic.

Conversion is initiated by a rising edge on the CONVST input; BUSY goes high during conversion and returns low upon completion. The device supports independent analog and digital ground pins (AGND/DGND) and includes internal clock generation - no external clock required.

Key Specifications

Pinout & Package

MX7821KN is housed in a 28-pin plastic DIP (dual in-line package) with 0.6-inch width, compatible with standard through-hole PCB assembly and socketing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed SAR ADC applications.

Compared with AD7821KNZ and MAX1166BCPP+, the MX7821KN uniquely combines 1.25 MSPS speed, internal 2.5V reference, and single +5V supply - enabling compact, low-complexity data acquisition in industrial and instrumentation designs without external support components.

Availability

MX7821KN is available at Aetrix Electronics and suitable for industrial automation, test equipment, motor control, and medical instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for MX7821KN 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, automotive, and communications applications.

The MX7821KN belongs to Maxim's high-speed data acquisition product line, engineered for embedded systems needing fast, accurate, and self-contained analog-to-digital conversion without external timing or reference components.

FAQ

What is the maximum sampling rate of the MX7821KN?

The MX7821KN achieves a maximum sampling rate of 1.25 million samples per second (MSPS). This performance is guaranteed under specified operating conditions including +5V supply, 25°C ambient temperature, and proper decoupling. The MX7821KN maintains its ±0.5 LSB INL specification across this full sampling range, making it suitable for demanding real-time acquisition tasks where timing determinism and accuracy are critical.

Does the MX7821KN require an external reference voltage?

No, the MX7821KN integrates a precision 2.5V bandgap reference, eliminating the need for external reference components. This internal reference is factory-trimmed and provides stable operation over temperature and supply variations. The MX7821KN's reference output can also be used to bias external circuitry, though loading must remain within datasheet limits to preserve ADC accuracy.

What package type is used for the MX7821KN?

The MX7821KN is supplied in a 28-pin plastic dual in-line package (PDIP) with 0.6-inch body width and 0.1-inch pin pitch. This through-hole package supports manual prototyping, socket-based testing, and legacy industrial PCB assemblies. Pin assignments match industry-standard layouts for 12-bit parallel-output ADCs, facilitating drop-in replacement in existing designs using compatible footprints.

How does the MX7821KN handle digital interface timing?

The MX7821KN uses a parallel CMOS-compatible interface with dedicated CONVST, BUSY, and OE signals. Conversion starts on the rising edge of CONVST; BUSY remains high until conversion completes; OE must be asserted low to enable D0–D11 outputs. The MX7821KN meets setup/hold timing requirements for common microcontrollers and FPGAs operating at 5V, with typical access time of 60 ns after OE activation.

Is the MX7821KN still in active production?

Yes, the MX7821KN remains in active production and is supported by Analog Devices (which acquired Maxim Integrated). Aetrix Electronics maintains inventory and offers long-term supply assurance, including last-time-buy planning and cross-reference guidance should future obsolescence occur. Product change notifications and lifecycle status for the MX7821KN are tracked and communicated proactively to registered customers.