Analog Devices Inc./Maxim Integrated MX7828KN+

Overview

MX7828KN+ from Maxim Integrated is an 8-channel, 8-bit CMOS analog-to-digital converter with 2.5 µs conversion time, single +5V supply operation, built-in track/hold, and 0V to +5V analog input range. It functions as a high-speed data acquisition front-end in real-time signal processing systems requiring multi-channel sampling without external sample-and-hold circuitry.

For engineers reviewing the MX7828KN+ datasheet, MX7828KN+ pinout, MX7828KN+ application, or MX7828KN+ equivalent, key selection considerations include its 8-channel multiplexer architecture, Mode 0/Mode 1 digital interface flexibility, open-drain RDY output for WAIT-state microprocessors, ±1/2 LSB total unadjusted error, and compatibility with AD7828 in DIP-28 package.

Technical Context

The MX7828KN+ employs a half-flash architecture with two 4-bit flash ADC sections and an internal DAC to generate the lower 4 bits from the residue voltage. Its timing is governed by CS/RD control signals, supporting both Mode 0 (WAIT-state) and Mode 1 (non-WAIT) microprocessor interfaces with distinct INT and RDY status outputs.

Analog input acquisition relies on internal 31 comparator inputs with ~45 pF total input capacitance and requires ≤100 Ω source impedance for full-spec settling within 1 µs. Reference configuration uses external VREF+ and VREF− pins (0V to VDD range), with no internal reference - unlike MAX158 - making it dependent on stable external reference voltage sources.

Key Specifications

Pinout & Package

MX7828KN+ is housed in a 28-pin plastic DIP package (0.600" wide), pin-compatible with Analog Devices AD7828. Pin functions are validated per Maxim's official pin description table and functional diagrams.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7828BNZ, MX7828KN+ offers tighter ±1/2 LSB accuracy and identical DIP-28 footprint; compared with MAX158CNG+, it trades internal reference convenience for lower power and direct AD7828 drop-in capability - making MX7828KN+ optimal for accuracy-critical, space-constrained upgrades of legacy AD7828 designs.

Availability

MX7828KN+ is available at Aetrix Electronics and suitable for high-speed data acquisition, telecommunications infrastructure monitoring, and industrial servo control requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for MX7828KN+ 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 precision analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.

The MX7824/MX7828 family was designed specifically for high-throughput, multi-channel data acquisition systems needing minimal external components, fast conversion, and seamless integration with 8-bit and 16-bit microprocessors.

FAQ

What is the operating temperature range for MX7828KN+?

The MX7828KN+ is rated for –40°C to +85°C operation, as confirmed by Maxim's Ordering Information table where "KN" suffix denotes this industrial temperature grade. This range supports deployment in base stations, factory automation controllers, and outdoor telecom equipment without derating. The MX7828KN+ maintains ±1/2 LSB total unadjusted error across this full range, ensuring consistent performance in thermally variable environments.

Does MX7828KN+ include an internal voltage reference?

No, MX7828KN+ does not include an internal voltage reference. Unlike the MAX158, it requires external VREF+ and VREF− connections to define the analog input range (0V to +5V). The "MX" prefix explicitly denotes the external-reference variant, whereas "MAX" parts (e.g., MAX158) integrate a 2.5V reference. Using MX7828KN+ with an unstable or noisy external reference will directly degrade accuracy and linearity.

Is MX7828KN+ pin-compatible with AD7828?

Yes, MX7828KN+ is fully pin-compatible with Analog Devices AD7828 in the 28-pin plastic DIP package. Pin functions, electrical characteristics, timing diagrams, and package dimensions match exactly, enabling direct replacement without PCB modification. This compatibility is explicitly stated in Maxim's General Description and verified across all signal, power, and ground pin assignments in the Pin Configurations diagram.

What are the key timing requirements for interfacing MX7828KN+ with an 8086 microprocessor?

For 8086 interface in Mode 0, MX7828KN+ requires CS and RD to be asserted simultaneously to initiate conversion; RDY must be connected to the 8086's READY input to extend the bus cycle. Critical timing parameters include tCRD = 2.5 µs (conversion time), tRDY ≤ 40 ns (CS-to-RDY delay), and tACC1 = 2.0 µs (data access after RD). These ensure the 8086 waits until valid DB0–DB7 data appears before completing the read cycle.

Can MX7828KN+ handle bipolar analog inputs?

MX7828KN+ accepts only unipolar 0V to +5V analog inputs directly. To process bipolar signals (e.g., ±4V), external signal conditioning is required - such as an op-amp level-shifter that maps –4V to 0V and +4V to +5V - as shown in Figure 10a of the datasheet. The MX7828KN+ itself has no hardware support for differential or offset-binary coding; output remains straight binary with zero code at VREF−.