Analog Devices Inc./Maxim Integrated MAX1290AEEI

Overview

MAX1290AEEI from Maxim Integrated is a 12-bit successive-approximation ADC with internal +2.5V reference, 400ksps sampling rate, and software-configurable 8-channel single-ended / 4-channel pseudo-differential analog input. 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 microcontrollers in portable data-acquisition systems.

For engineers reviewing the MAX1290AEEI datasheet, MAX1290AEEI pinout, MAX1290AEEI application, or MAX1290AEEI equivalent, this page delivers verified specifications, validated pin functions, confirmed operating modes (unipolar/bipolar, internal/external clock/acquisition), real-world timing constraints (e.g., 3.2µs conversion time, 2µs wake-up), and precise thermal performance across –40°C to +85°C.

Technical Context

The MAX1290AEEI implements a charge-redistribution SAR architecture with integrated track-and-hold, supporting both internal and external clock modes (7.6MHz max) and internal/external acquisition control. Its analog front-end includes programmable unipolar/bipolar range selection and channel multiplexing via an 8-bit control byte with address bits A2–A0 and mode bits SGL/DIF, UNI/BIP, ACQMOD, and PD1/PD0.

It features a byte-wide parallel (8 + 4) interface with HBEN-controlled MSB/LSB multiplexing, tri-state INT output synchronized to CS, and on-chip power-down modes reducing supply current to 2µA. The device uses a 12pF capacitive DAC and achieves ±0.5 LSB INL at –40°C to +85°C, with full-power bandwidth of 6MHz and full-linear bandwidth of 350kHz.

Key Specifications

Pinout & Package

MAX1290AEEI is housed in a 28-pin QSOP package with exposed pad (not thermally enhanced). Pin functions are electrically validated per Maxim's official pin description table and timing diagrams. All pins support TTL/CMOS-compatible voltage levels and include ESD protection diodes on analog inputs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1290ACEI, the MAX1290AEEI guarantees ±0.5 LSB INL across –40°C to +85°C and supports industrial ambient conditions; compared with ADS7822U, it provides 4× higher resolution, parallel interface simplicity, and integrated reference - eliminating two external components and simplifying timing-critical designs.

Availability

MAX1290AEEI is available at Aetrix Electronics and suitable for industrial control systems, portable patient monitors, energy metering hardware, and battery-powered data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1290AEEI 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, medical, and communications applications.

The MAX1290AEEI belongs to Maxim's precision data-converter product line, designed specifically for low-power, high-accuracy analog-to-digital conversion in space-constrained, battery-operated, and thermally demanding embedded systems.

FAQ

What is the guaranteed integral nonlinearity (INL) specification for MAX1290AEEI over its full operating temperature range?

The MAX1290AEEI guarantees ±0.5 LSB INL over its specified –40°C to +85°C operating temperature range, as confirmed in the Electrical Characteristics table of the official datasheet (Rev 3, 12/02). This specification applies to the MAX1290AEEI variant specifically and is validated across all process corners and supply conditions - unlike the MAX1290ACEI, which specifies ±0.5 LSB only at +25°C. The MAX1290AEEI maintains this linearity without calibration.

Does MAX1290AEEI support both unipolar and bipolar input configurations, and how is this controlled?

Yes, the MAX1290AEEI supports both unipolar (0V to VREF) and bipolar (–VREF/2 to +VREF/2) analog input ranges. This is configured via the UNI/BIP bit (D3) in the 8-bit control byte written to the device during initialization. When UNI/BIP = 1, the converter operates in unipolar mode; when UNI/BIP = 0, it operates in bipolar mode. The MAX1290AEEI's internal reference and input structure maintain full 12-bit accuracy in both modes without external component changes.

What is the minimum acquisition time required before conversion starts in internal acquisition mode for MAX1290AEEI?

In internal acquisition mode, the MAX1290AEEI requires a minimum acquisition time of 3.2µs, defined as tACQ in the Timing Characteristics table. This value is fixed and internally timed - no external timing control is needed. The acquisition interval ends automatically after three clock cycles (≈1µs in internal clock mode) or after the specified 3.2µs delay, after which conversion begins. This parameter is guaranteed across –40°C to +85°C and independent of source impedance below 3kΩ.

Can MAX1290AEEI operate with an external reference, and what modifications are required?

Yes, the MAX1290AEEI can operate with an external reference applied to the REF pin. To disable the internal +2.5V reference, REFADJ must be connected to VDD, and a 0.01µF capacitor must be placed from REFADJ to GND. The external reference must be stable, low-noise, and capable of driving the REF pin capacitance (12pF typical). No firmware or control-byte changes are required - the device automatically uses the voltage present at REF as its full-scale reference.

How does the HBEN pin affect data output formatting on the D7–D0 bus for MAX1290AEEI?

The HBEN (High-Byte Enable) pin determines whether the D7–D0 bus presents the 8 least-significant bits (HBEN = 0) or the 4 most-significant bits (HBEN = 1) of the 12-bit conversion result. When HBEN = 1, D3–D0 carry D11–D8 and D7–D4 are high-impedance; when HBEN = 0, D7–D0 carry D7–D0 and D11–D8 are accessed separately. This multiplexing reduces bus width requirements and enables compatibility with 8-bit microcontrollers without external latches.