Analog Devices Inc./Maxim Integrated MAX118CPI

Overview

MAX118CPI from Maxim Integrated is an 8-bit, 8-channel analog-to-digital converter (ADC) with half-flash architecture, 1 Msps sampling rate, 660 ns conversion time, ±1 LSB total unadjusted error, and 1 µA power-down current. It operates from a single +5V supply and integrates a track/hold circuit for digitizing fast analog signals in burst-mode data acquisition systems.

For engineers reviewing the MAX118CPI datasheet, MAX118CPI pinout, MAX118CPI application, or MAX118CPI equivalent, this page delivers verified electrical parameters, validated 28-pin DIP pin mapping, confirmed ratiometric reference operation, and real-world timing behavior in read and write-read interface modes.

Technical Context

The MAX118CPI implements a two-stage half-flash conversion architecture: a 4-bit flash ADC generates the MSBs and drives an internal DAC to produce a residue voltage, which is then quantized by a second 4-bit flash ADC to yield the LSBs. This achieves 8-bit resolution with only 15 comparators and eliminates need for external clocking.

It supports dual digital interface modes-read mode (MODE = 0) using RD as control and WR/RDY as ready-status output, and write-read mode (MODE = 1) where WR initiates conversion and INT signals completion. Channel selection is controlled via A0–A2 address inputs, with IN8 hardwired to monitor REF+ in the MAX118 variant.

Key Specifications

Pinout & Package

MAX118CPI is packaged in a 28-pin wide plastic DIP (dual in-line package), 0.600-inch body width, through-hole mountable, with 0.100-inch lead pitch and standard JEDEC MO-019 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX1166CPE+, the MAX118CPI uniquely combines 1 Msps parallel-interface throughput, integrated track/hold, and 1 µA power-down in a single +5V 28-pin DIP-making it irreplaceable for legacy µP-based high-speed burst acquisition where layout space and interface simplicity are critical.

Availability

MAX118CPI is available at Aetrix Electronics and suitable for high-speed DSP front-ends, remote data acquisition nodes, and portable test equipment requiring stable component supply across extended production lifecycles.

Supply support for MAX118CPI 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 applications.

The MAX114/MAX118 product line was designed for microprocessor-based systems needing fast, low-power, multi-channel digitization without external clocks or interface logic-targeting data acquisition, instrumentation, and real-time control.

FAQ

What is the operating temperature range for the MAX118CPI?

The MAX118CPI is rated for commercial-grade operation from 0°C to +70°C. This range is explicitly defined in the Ordering Information section of the datasheet and applies to the 'C' grade suffix. It is not qualified for extended industrial or military temperature ranges; alternative variants like MAX118EPI (−40°C to +85°C) or MAX118MJI (−55°C to +125°C) must be selected for those conditions. The MAX118CPI's electrical specifications-including conversion time, TUE, and power consumption-are guaranteed only within this 0°C to +70°C window.

Does the MAX118CPI require an external clock signal?

No, the MAX118CPI does not require an external clock signal. Its half-flash architecture uses internal timing generation, and all conversion timing-including 660 ns conversion time-is self-contained. The device relies solely on control signals (CS, RD, WR, PWRDN) and address lines (A0–A2) for operation. This eliminates clock distribution challenges, jitter sensitivity, and BOM cost associated with external oscillators, making the MAX118CPI especially suitable for noise-sensitive or space-constrained µP-based systems.

How does the IN8 channel function in the MAX118CPI?

In the MAX118CPI, the IN8 channel is internally hardwired to REF+, meaning it continuously monitors the reference voltage level whenever selected via A2–A0 = 111. This provides a built-in diagnostic capability to verify reference stability without external connections. Unlike IN1–IN7, IN8 cannot accept an external analog signal; its sole purpose is reference supervision. This feature is unique to the MAX118 family and is not present in the 4-channel MAX114.

What is the minimum acquisition time (tACQ) requirement for reliable operation of the MAX118CPI?

The minimum acquisition time tACQ for the MAX118CPI is 160 ns, as specified in the Timing Characteristics table for all grades at TA = +25°C. This interval must elapse between address stabilization (A0–A2 valid) and initiation of conversion (falling edge of RD or WR). Failure to meet tACQ risks incomplete settling of the internal track/hold amplifier, leading to increased differential nonlinearity or code-dependent errors. At temperature extremes, tACQ may increase slightly, but the 160 ns value remains the design target for robust operation.

Can the MAX118CPI operate with a reference voltage other than +5V?

Yes, the MAX118CPI supports ratiometric operation with any valid REF+ and REF− pair where GND ≤ VREF− < VREF+ ≤ VDD. While REF+ is commonly tied to VDD (+5V), it can be set to lower values (e.g., 4.096V using MAX874) to improve resolution for low-voltage sensors. The key constraint is that the reference span (VREF+ − VREF−) defines full-scale range, and the internal 1 kΩ reference resistance draws current even in power-down mode-requiring careful design of reference switching if ultra-low standby current is critical.