Analog Devices Inc./Maxim Integrated MAX1290ACEI+T

Overview

MAX1290ACEI+T from Maxim Integrated is a 12-bit successive-approximation analog-to-digital converter (ADC) with integrated +2.5V reference, byte-wide parallel (8+4) interface, and software-configurable 8-channel single-ended or 4-channel pseudo-differential input multiplexer. It operates from a single +5V analog supply and supports digital logic levels from +2.7V to +5.5V via VLOGIC, enabling direct interfacing with mixed-voltage microprocessors in portable data-acquisition systems.

For engineers reviewing the MAX1290ACEI+T datasheet, MAX1290ACEI+T pinout, MAX1290ACEI+T application, or MAX1290ACEI+T equivalent, this device delivers 400ksps sampling at 2.5mA supply current, ±0.5 LSB INL, 6MHz full-power bandwidth, and 2µs wake-up from shutdown - critical for battery-powered industrial sensors and medical patient monitors requiring precision, low power, and rapid response.

Technical Context

The MAX1290ACEI+T implements a capacitive charge-redistribution SAR architecture with an internal track-and-hold stage, supporting both internal and external clock modes (7.6MHz max) and internal/external acquisition control. Its analog front-end allows unipolar/bipolar and single-ended/pseudo-differential configurations via a software-defined control byte.

Conversion timing is deterministic: 13 clock cycles per conversion, with aperture delay of 25ns and acquisition time of 3.2µs (typ). The device tri-states INT on CS high and uses HBEN to multiplex 12-bit output across an 8-bit data bus - enabling compact µP interface without external latches.

Key Specifications

Pinout & Package

MAX1290ACEI+T is housed in a 28-pin QSOP (0.154" wide) package with exposed pad not electrically connected. Pin functions are validated per Maxim's official pin description table and functional diagram (Rev 3, Dec 2002).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1290ACEI+T, MAX1290BCNI+ trades QSOP compactness for extended temperature grade and relaxed linearity, while ADS7822U replaces parallel throughput and internal reference with serial simplicity and minimal footprint - guiding selection based on interface architecture, thermal environment, and layout constraints.

Availability

MAX1290ACEI+T is available at Aetrix Electronics and suitable for industrial process monitoring, patient vital sign acquisition, energy meter data logging, and touchscreen controller interface applications requiring stable component supply and long-term manufacturability.

Supply support for MAX1290ACEI+T 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 and mixed-signal ICs for demanding industrial, medical, and communications applications, emphasizing integration, low power, and robust performance.

The MAX1290ACEI+T belongs to Maxim's high-speed, low-power ADC product line, engineered specifically for portable and space-constrained data-acquisition systems needing integrated reference, flexible input configuration, and µP-friendly parallel interface.

FAQ

What is the operating temperature range for the MAX1290ACEI+T?

The MAX1290ACEI+T is specified for commercial-grade operation from 0°C to +70°C. This range is confirmed in the Ordering Information table and Absolute Maximum Ratings section of the datasheet, and applies to all electrical specifications unless otherwise noted. The device maintains ±0.5 LSB INL and 400ksps sampling rate across this full range.

Does the MAX1290ACEI+T require an external clock to operate?

No, the MAX1290ACEI+T supports both internal and external clock modes. When configured for internal clock mode (D7=1, D6=0 in control byte), it generates its own 7.6MHz clock internally - eliminating the need for an external oscillator. The CLK pin must be tied to VDD or GND in this mode to prevent floating.

How does the HBEN pin function in the MAX1290ACEI+T parallel interface?

The HBEN (High-Byte Enable) pin controls multiplexing of the 12-bit conversion result onto the 8-bit data bus. When HBEN = 1, D0–D7 carry bits D8–D11 (MSB nibble); when HBEN = 0, D0–D7 carry bits D0–D7 (LSB nibble). This allows full 12-bit data transfer using only 8 data lines plus one control signal.

Can the MAX1290ACEI+T interface directly with a 3.3V microprocessor?

Yes, the MAX1290ACEI+T supports mixed-voltage operation via the VLOGIC pin, which accepts +2.7V to +5.5V. When VLOGIC = 3.3V, all digital outputs (D0–D7, INT, RD, WR, CS) are 3.3V-tolerant, and input thresholds (VIH/VIL) scale accordingly - enabling seamless interfacing with 3.3V µPs without level shifters.

What is the purpose of the REFADJ pin on the MAX1290ACEI+T?

The REFADJ pin serves dual roles: as the bandgap reference buffer output (when internal reference is active) and as a bandgap reference buffer input (when external reference is used). When using the internal +2.5V reference, REFADJ is bypassed to GND with 0.01µF; when using an external reference, REFADJ is tied to VDD to disable the internal bandgap.