Analog Devices Inc./Maxim Integrated MX7575KN+

Overview

MX7575KN+ from Maxim Integrated is an 8-bit, microprocessor-compatible analog-to-digital converter (ADC) with on-chip track/hold, 5µs conversion time, ±1LSB total unadjusted error, and 50kHz full-power signal bandwidth. It operates from a single +5V supply with external 1.23V reference and interfaces directly to 8-bit µP data buses via CS, RD, and BUSY control signals for high-speed data acquisition in real-time control systems.

For engineers reviewing the MX7575KN+ datasheet, MX7575KN+ pinout, MX7575KN+ application, or MX7575KN+ equivalent, this page delivers verified technical context, exact pin-level interface behavior, timing-critical µP interface modes (slow-memory and ROM), and validated alternatives for embedded signal acquisition where sampling jitter, bus compatibility, and power-constrained operation matter.

Technical Context

The MX7575KN+ uses successive-approximation architecture with internal DAC and comparator, acquiring input voltage once at the start of conversion via its integrated track/hold circuit. Sampling occurs precisely on the third falling edge of CLK after CS and RD go low, enabling deterministic jitter-free acquisition for synchronous signal processing.

It supports three µP interface modes: slow-memory (BUSY-driven wait state), ROM interface (non-blocking read with pipelined conversion), and - unlike the MX7576 - does not support asynchronous mode. Its clock subsystem accepts either 4MHz external TTL/CMOS clocks or internal RC-generated clocks (RCLK=100kΩ, CCLK=100pF), with internal division-by-two ensuring duty-cycle insensitivity.

Key Specifications

Pinout & Package

MX7575KN+ is housed in an 18-pin plastic DIP package (0°C to +70°C operating range), with dual ground pins (AGND and DGND) and dedicated analog/digital separation for noise-sensitive ADC operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX165, MX7575KN+ offers external reference flexibility and lower quiescent current; compared with AD7820KN, it provides single-supply operation and integrated track/hold - making MX7575KN+ the optimal choice for cost-sensitive, +5V µP-based acquisition where 5µs speed and ±1LSB accuracy are design requirements.

Availability

MX7575KN+ is available at Aetrix Electronics and suitable for high-speed data acquisition, telecommunications monitoring, and audio signal digitization requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MX7575KN+ 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 high-reliability ICs for industrial, communications, and computing applications.

The MX7575KN+ belongs to Maxim's legacy high-speed µP-compatible ADC product line, designed specifically for embedded systems demanding fast, accurate, and bus-transparent analog digitization without external support components.

FAQ

What is the maximum input signal frequency the MX7575KN+ can accurately digitize?

The MX7575KN+ supports full-power bandwidth up to 50kHz - meaning it can accurately capture 2.46V_P-P sine waves at that frequency with ≤1LSB error. This is enabled by its on-chip track/hold circuit and 386mV/µs slew rate capability. Performance degrades above 50kHz due to aperture uncertainty and SNR roll-off shown in Figure 13 of the datasheet. For signals above 50kHz, anti-alias filtering is required prior to the MX7575KN+ AIN pin.

Does the MX7575KN+ require an external clock, or can it operate with an internal oscillator?

The MX7575KN+ supports both configurations: it can use a 4MHz external clock applied to the CLK pin, or generate its own clock using an external RCLK (100kΩ) and CCLK (100pF) network. Internal oscillation may vary ±50% due to process drift, so external clocking is recommended for timing-critical applications where conversion time must stay within 5µs ±10%. The internal option simplifies BOM for non-critical sampling.

How does the MX7575KN+ handle analog input impedance, and what is the maximum recommended source resistance?

The MX7575KN+ analog input presents 10MΩ DC impedance but includes 10pF input capacitance. To ensure <7ns hold settling to ±1/4LSB and avoid gain/offset errors, the driving source impedance must be ≤2kΩ. Higher impedances cause incomplete charging of the internal sampling capacitor, leading to code-dependent errors. A unity-gain buffer (e.g., rail-to-rail op amp) is strongly advised for high-Z sensors or passive filters.

Can the MX7575KN+ be used in bipolar input configurations, and how is that implemented?

Yes - the MX7575KN+ supports bipolar operation via external resistor networks (e.g., Figure 18a), producing offset-binary output codes for ±2.46V input ranges. AIN remains unipolar (0–2.46V), while external op-amp circuitry shifts and scales the signal. Calibration steps for offset and full-scale are defined in the datasheet; 0.1% resistors are recommended for <±1LSB system error. No internal hardware changes are needed - only external analog front-end redesign.

What are the critical layout considerations for grounding and decoupling the MX7575KN+?

Separate AGND and DGND planes must be used and joined at a single point near the MX7575KN+ VDD pin. AGND carries analog return currents only; DGND handles digital switching noise. Place a 0.1µF ceramic capacitor between VDD and DGND, and a 47µF tantalum between VDD and AGND - both within 5mm of the pins. Route AIN, REF, and CLK traces away from digital lines, and avoid vias under the IC body to preserve ground integrity for the 18-pin DIP package.