Analog Devices Inc./Maxim Integrated MAX118EPI+

Overview

MAX118EPI+ from Maxim Integrated is an 8-bit, 8-channel analog-to-digital converter (ADC) with half-flash architecture, 1Msps sampling rate, 660ns conversion time, ±1LSB total unadjusted error, and 1µA power-down current. It operates from a single +5V supply, integrates a track/hold circuit, and supports ratiometric operation for precision data acquisition in portable instrumentation.

For engineers reviewing the MAX118EPI+ datasheet, MAX118EPI+ pinout, MAX118EPI+ application, or MAX118EPI+ equivalent, this page delivers verified electrical parameters, validated 28-pin wide DIP package mapping, confirmed microprocessor-compatible parallel interface behavior, and real-world timing constraints for burst-mode and high-speed DSP integration.

Technical Context

The MAX118EPI+ uses a two-stage half-flash conversion technique: a 4-bit flash ADC generates the MSBs and drives an internal DAC to produce a residue voltage, which a second 4-bit flash ADC converts to the LSBs-achieving full 8-bit resolution with only 15 comparators. Its internal analog multiplexer selects among eight input channels under A0–A2 address control, with IN8 hardwired to monitor REF+.

Digital interface operation depends on the MODE pin: in read mode (MODE = GND), RD initiates conversion and RDY signals readiness; in write-read mode (MODE = VDD), WR starts conversion and INT flags completion. Pipelined operation is supported by tying WR to RD, enabling concurrent conversion and data readout.

Key Specifications

Pinout & Package

MAX118EPI+ is housed in a 28-pin wide plastic DIP (dual in-line package) with 0.600-inch body width and 0.100-inch lead pitch, rated for −40°C to +85°C industrial operation.

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 MAX118EPI+ uniquely combines 1Msps parallel-interface speed, integrated track/hold, and true ratiometric operation in a proven industrial-grade DIP package-making it optimal for µP-based systems requiring minimal interface overhead and robust analog signal integrity.

Availability

MAX118EPI+ is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor interfaces, communications baseband processing, and high-speed test equipment requiring stable component supply across extended temperature ranges.

Supply support for MAX118EPI+ 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 demanding industrial, automotive, and communications applications.

The MAX118EPI+ belongs to Maxim's high-speed data acquisition product line, engineered specifically for µP-based systems needing low-power, multi-channel digitization with minimal external components and guaranteed monotonic performance.

FAQ

What is the maximum sampling rate achievable with MAX118EPI+ in write-read mode?

The MAX118EPI+ achieves a maximum sampling rate of 1.23Msps in write-read mode when tRD < tINTL, calculated as 1/(tWR + tRD + tRI + tACQ) = 1/(250ns + 250ns + 150ns + 160ns). This assumes optimal timing margins and load conditions per the datasheet's CL = 50pF test setup. Real-world throughput may vary slightly due to PCB trace capacitance and µP timing tolerances, but the MAX118EPI+ consistently delivers ≥1Msps across its −40°C to +85°C operating range.

Does MAX118EPI+ require an external clock source?

No, the MAX118EPI+ does not require an external clock source. All timing is derived internally using on-chip control logic synchronized to the WR and RD strobes. The 660ns conversion time is fixed and guaranteed under specified supply and load conditions. This eliminates clock distribution complexity and jitter sensitivity, making the MAX118EPI+ especially suitable for µP systems where clock resources are limited or shared.

How does the internal track/hold function in MAX118EPI+ affect signal acquisition?

The internal track/hold in the MAX118EPI+ enters hold mode at the start of conversion (on falling WR or RD) and releases to track mode after INT goes high. Its 1MHz full-power bandwidth and 15V/µs slew rate allow accurate capture of fast transients without external components. Acquisition time (tACQ = 160ns minimum) must be respected to ensure the held voltage settles within 1/2LSB-critical for maintaining the ±1LSB total unadjusted error specification of the MAX118EPI+.

Can MAX118EPI+ operate with a 3V supply?

No, the MAX118EPI+ is specified only for +5V ±5% operation (4.75V to 5.25V). It lacks 3V compatibility; for +3V applications, Maxim recommends the pin-compatible MAX117 family. Attempting to power the MAX118EPI+ from 3V will result in undefined behavior, failure to meet AC specifications such as SINAD and THD, and potential violation of absolute maximum ratings for digital input thresholds. Always verify supply voltage compliance before integrating the MAX118EPI+ into low-voltage designs.

What is the purpose of the IN8 channel in MAX118EPI+?

The IN8 channel in the MAX118EPI+ is internally hardwired to REF+, providing a dedicated means to monitor reference voltage stability in real time. When A2–A0 = 111, the multiplexer selects IN8 and returns the digitized value of REF+, enabling system-level diagnostics of reference drift or dropout. This feature eliminates the need for external monitoring circuitry and supports self-calibration routines-enhancing reliability in applications like portable medical devices where reference integrity directly impacts measurement safety and accuracy. The MAX118EPI+ datasheet explicitly confirms this fixed connection in Table 1 and the Functional Diagram.