Analog Devices Inc./Maxim Integrated MAX120ENG+

Overview

The MAX120ENG+ from Maxim Integrated is a 12-bit, 500ksps BiCMOS sampling analog-to-digital converter with integrated track/hold and -5V buried-zener reference, operating over -40°C to +85°C in a 24-pin narrow DIP package. It accepts ±5V bipolar analog inputs (overvoltage tolerant to ±15V), achieves 70dB SINAD and -82dB THD, and interfaces directly to microprocessors or FIFO buffers via TTL/CMOS-compatible 12-bit parallel bus.

For engineers reviewing the MAX120ENG+ datasheet, MAX120ENG+ pinout, MAX120ENG+ application, or MAX120ENG+ equivalent, key selection considerations include its 1.6µs conversion time, ±1 LSB INL, dual-supply operation (-15.75V VSS / +5.25V VDD), continuous-conversion mode support, and compatibility with 0.1–8MHz external clocks - critical for high-speed data acquisition and spectrum analysis systems requiring stable DC accuracy and dynamic performance across industrial temperature ranges.

Technical Context

The MAX120ENG+ employs successive approximation architecture with an internal track/hold circuit featuring 350ns acquisition time and 10ns aperture delay, enabling precise sampling of wideband signals up to 1.5MHz full-power input bandwidth. Its on-chip -5V reference exhibits ±25ppm/°C drift and supports external loading up to 5mA.

It operates in five configurable interface modes (full-control, stand-alone, slow-memory, ROM, continuous-conversion), with MODE pin selection determining INT/BUSY behavior and RD/CS/CONVST logic defining conversion initiation and data-read timing. All digital I/Os are TTL/CMOS compatible, and bus-relinquish time is as low as 30ns.

Key Specifications

Pinout & Package

MAX120ENG+ is housed in a 24-pin narrow plastic DIP (PDIP) package with 0.3-inch width, RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX122ENG+, the MAX120ENG+ delivers 50% higher throughput and tighter timing control at 8MHz clocks, while versus ADS7800KP it eliminates external reference and T/H components - reducing bill-of-materials cost and improving temperature stability in industrial data loggers and spectrum analyzers.

Availability

MAX120ENG+ is available at Aetrix Electronics and suitable for high-speed data acquisition, spectrum analysis, and digital-signal processing applications requiring stable component supply across extended industrial temperature ranges (-40°C to +85°C).

Supply support for MAX120ENG+ 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, medical, and communications markets.

The MAX120/MAX122 product line was engineered for high-fidelity, high-throughput data acquisition in noise-sensitive environments - integrating reference, track/hold, and µP interface to minimize external components and maximize DC accuracy and dynamic performance.

FAQ

What is the operating temperature range of the MAX120ENG+?

The MAX120ENG+ is rated for operation from -40°C to +85°C, making it suitable for industrial and automotive under-hood applications where ambient temperatures exceed commercial-grade limits. This extended range is confirmed in the Ordering Information table and applies specifically to the ENG+ variant, distinguishing it from the CNG+ (0°C to +70°C) version.

Does the MAX120ENG+ require external components for basic operation?

Yes - the MAX120ENG+ requires decoupling capacitors on VDD, VSS, and VREF pins: 0.1µF ceramic + 10µF bulk for VDD/VSS, and 0.1µF ceramic + 22µF electrolytic (ESR ≤100mΩ) for VREF. No external track/hold capacitor or reference is needed, as both are integrated. These values are specified in the Pin Description and Layout sections of the datasheet.

How does the MODE pin affect the MAX120ENG+ interface behavior?

The MODE pin configures the INT/BUSY output function: tied to VDD yields an interrupt pulse (low on conversion complete, high after read); tied to DGND or left open yields a busy flag (low during conversion, high when data is ready). This setting also determines timing relationships for RD/CS handshaking and is validated across all five operational modes in the Timing Characteristics table.

Can the MAX120ENG+ operate with a single +5V supply?

No - the MAX120ENG+ requires dual supplies: +4.75V to +5.25V on VDD and -10.8V to -15.75V on VSS. The negative rail powers the internal -5V reference and analog comparator, and operation outside this range violates Absolute Maximum Ratings. Single-supply alternatives like the ADS7800KP exist but lack integrated reference and bipolar input capability.

What is the significance of the ±1 LSB INL specification for the MAX120ENG+?

The ±1 LSB integral nonlinearity (INL) means the maximum deviation between the actual transfer function and ideal straight line is within one least-significant bit across the full ±5V input range. This ensures monotonicity and <0.025% full-scale error - critical for precision instrumentation, closed-loop control, and calibration-critical data logging where code-to-code consistency must be guaranteed over temperature.