Analog Devices Inc./Maxim Integrated MAX1090AEEI+

Overview

MAX1090AEEI+ from Maxim Integrated is a 10-bit successive-approximation ADC with 8-channel single-ended / 4-channel pseudo-differential analog input, internal +2.5V reference, and byte-wide parallel (8+2) interface. It operates from a single +5V analog supply and supports digital logic levels from +2.7V to +5.5V via VLOGIC. Designed for battery-powered data acquisition, it delivers 400ksps sampling at 2.5mA supply current and features 2µs wake-up from shutdown.

For engineers reviewing the MAX1090AEEI+ datasheet, MAX1090AEEI+ pinout, MAX1090AEEI+ application, or MAX1090AEEI+ equivalent, key selection criteria include its ±0.5 LSB INL, software-configurable unipolar/bipolar mode, 6MHz full-power bandwidth track/hold, QSOP-28 package compatibility, and support for both internal and external clock acquisition modes.

Technical Context

The MAX1090AEEI+ implements a charge-redistribution SAR architecture with an integrated track-and-hold stage, enabling precise sampling of fast transients up to 6MHz. Its analog input multiplexer supports eight single-ended channels (CH0–CH7) or four pseudo-differential pairs, with COM referenced zero-code voltage stability required within ±0.5 LSB during conversion.

Control is executed via an 8-bit configuration byte that sets acquisition mode (internal/external), clock source (internal/external), power-down state (full/standby), input polarity (unipolar/bipolar), and channel address (A2–A0). The device tri-states INT when CS is high and uses HBEN to multiplex the 10-bit result across D7–D0 and D1/D9, D0/D8 pins.

Key Specifications

Pinout & Package

MAX1090AEEI+ is housed in a 28-pin QSOP package (5.0mm × 10.2mm body, 0.635mm pitch), optimized for space-constrained PCB layouts while maintaining thermal performance up to +85°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit parallel ADC applications.

Compared with MAX1090ACEI+, the MAX1090AEEI+ adds -40°C to +85°C operation for harsh environments, while ADS7822U trades resolution, interface, and integration for smaller footprint-making MAX1090AEEI+ optimal for new designs needing precision, parallel simplicity, and industrial temperature compliance.

Availability

MAX1090AEEI+ 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 across extended temperature ranges.

Supply support for MAX1090AEEI+ 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 systems.

The MAX1090AEEI+ belongs to Maxim's low-power, high-speed data acquisition ADC family, engineered specifically for space- and power-constrained applications requiring integrated reference, flexible input configuration, and direct µP interfacing.

FAQ

What is the operating temperature range of the MAX1090AEEI+?

The MAX1090AEEI+ is rated for -40°C to +85°C operation, making it suitable for industrial and automotive-adjacent environments where extended thermal stability is required. This differs from the MAX1090ACEI+ (0°C to +70°C) and MAX1090BEEI+ (±1 LSB INL, same temperature range). The MAX1090AEEI+ maintains ±0.5 LSB INL across this full range, verified per datasheet Table 1.

Does the MAX1090AEEI+ require an external clock to operate?

No, the MAX1090AEEI+ supports both internal and external clock modes. When bits D7=1 and D6=0 in the control byte, the internal 6MHz clock is enabled-requiring only CLK pin tied high or low. External clock mode (D7=D6=1) accepts 100kHz–7.6MHz TTL/CMOS signals. Internal clock reduces µP overhead but increases aperture jitter to 200ps vs. 50ps in external acquisition mode.

How does the MAX1090AEEI+ handle analog input protection?

The MAX1090AEEI+ integrates internal clamping diodes on all analog inputs (CH0–CH7, COM), allowing safe operation from (GND − 300mV) to (VDD + 300mV). For accurate full-scale conversion, input voltages should stay within (GND − 50mV) to (VDD + 50mV). If off-channel inputs exceed supplies by >50mV, forward current must be limited to ≤4mA using series resistance.

Can the MAX1090AEEI+ interface directly with a 3.3V microprocessor?

Yes-the MAX1090AEEI+ features a dedicated VLOGIC pin supporting +2.7V to +5.5V digital supply, enabling direct connection to 3.3V µPs without level shifters. Digital outputs (D7–D0, INT) are referenced to VLOGIC, and input thresholds (VIH/VIL) scale accordingly. VLOGIC must be bypassed with a 0.1µF capacitor to GND for noise immunity.

What is the function of the HBEN pin on the MAX1090AEEI+?

HBEN (High Byte Enable) controls multiplexing of the 10-bit conversion result across the 8-bit data bus. When HBEN = 1, D7–D0 carry D9/D8 (MSBs); when HBEN = 0, they carry D7–D0 (LSBs). This allows full 10-bit reads in two consecutive cycles, preserving compatibility with standard 8-bit µP data buses without requiring wider traces or additional I/O lines.