Analog Devices Inc./Maxim Integrated MAX1090AEEI+T

Overview

MAX1090AEEI+T from Maxim Integrated is a 10-bit successive-approximation ADC with internal +2.5V reference, 8-channel single-ended / 4-channel pseudo-differential analog input multiplexer, and byte-wide parallel (8+2) interface. It operates from a single +5V analog supply with user-adjustable digital logic level (+2.7V to +5.5V), delivers 400ksps sampling rate, and achieves ±0.5 LSB INL at –40°C to +85°C. It is used in portable patient monitoring systems requiring low-power, high-accuracy digitization of biopotential signals.

For engineers reviewing the MAX1090AEEI+T datasheet, MAX1090AEEI+T pinout, MAX1090AEEI+T application, or MAX1090AEEI+T equivalent, key selection criteria include its software-configurable unipolar/bipolar input mode, 2µs wake-up from shutdown, tri-state INT output, internal track/hold with 6MHz full-power bandwidth, and QSOP-28 package compatibility with industrial data-acquisition layouts.

Technical Context

The MAX1090AEEI+T implements a capacitive charge-redistribution SAR architecture with integrated track-and-hold, supporting both internal and external clock modes. Its analog front-end includes a programmable 8:1 input multiplexer, COM-referenced single-ended operation, and pseudo-differential pairing (CH0/CH1, CH2/CH3, etc.), all configurable via an 8-bit control byte with SGL/DIF, UNI/BIP, and ACQMOD bits.

Digital interfacing uses a parallel (8+2)-bit bus with HBEN-controlled MSB/LSB multiplexing, active-low CS/WR/RD controls, and interrupt-driven readout via open-drain INT. Power management includes two software-selectable power-down modes-standby (≤10µA) and full shutdown (≤2µA)-with automatic wake-up on CS/WR activity and 2µs recovery to full operation.

Key Specifications

Pinout & Package

MAX1090AEEI+T is housed in a 28-pin QSOP (Quarter-Size Outline Package) with 0.15mm lead pitch and 4.4mm body width, compatible with standard surface-mount reflow profiles and IPC-7351B footprint IPC-7351B-QSOP28_390X175-1MM.

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+T adds industrial temperature support (–40°C to +85°C) and tighter long-term stability, while ADS7822U trades resolution, interface simplicity, and integration for smaller size and lower unit cost - making it unsuitable as a drop-in replacement but viable for cost-optimized 8-bit systems.

Availability

MAX1090AEEI+T is available at Aetrix Electronics and suitable for industrial process monitoring, portable patient monitoring, energy metering, and resistive touchscreen controller applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1090AEEI+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, mixed-signal, and power-management ICs for industrial, medical, and communications systems, with emphasis on integration, low power, and rugged performance.

The MAX1090 series belongs to Maxim's high-accuracy, low-power data-acquisition portfolio, engineered specifically for battery-operated and space-constrained instrumentation where internal reference, parallel interface, and wide temperature operation are essential.

FAQ

What is the guaranteed operating temperature range for MAX1090AEEI+T?

The MAX1090AEEI+T is specified for continuous operation from –40°C to +85°C, as confirmed by its AEEI grade suffix and electrical characteristics tables covering that full range. This makes MAX1090AEEI+T suitable for deployment in outdoor industrial enclosures, automotive cabin modules, and portable medical devices exposed to ambient thermal extremes without derating.

Does MAX1090AEEI+T require an external clock to operate?

No, MAX1090AEEI+T supports both internal and external clock modes. When configured for internal clock mode (D7=1, D6=0 in control byte), the device uses an on-chip oscillator and requires CLK pin to be tied to VDD or GND. External clock mode (D7=D6=1) accepts 100kHz–7.6MHz TTL/CMOS signals on CLK pin - allowing MAX1090AEEI+T flexibility across microcontroller-based and fixed-frequency system designs.

How does the HBEN pin affect data readout timing in MAX1090AEEI+T?

HBEN determines how the 10-bit conversion result is presented on the 8-bit data bus: when HBEN=0, D7–D0 carry the 8 LSBs; when HBEN=1, D1/D0 carry D9/D8 and D7–D2 carry D7–D2. Two consecutive RD cycles are required to read the full result, with HBEN state controlling which byte appears first. This design allows MAX1090AEEI+T to interface directly with 8-bit processors without external latch logic.

Can MAX1090AEEI+T operate with a 3.3V digital supply?

Yes, MAX1090AEEI+T supports VLOGIC from +2.7V to +5.5V, so it can interface directly with 3.3V microcontrollers or FPGAs. The digital outputs (D7–D0, INT, RD, WR, CS, HBEN) are fully compliant at VLOGIC = 3.3V, with VOH ≥ VLOGIC – 0.5V and VOL ≤ 0.4V, ensuring reliable logic-level translation without level shifters - a key advantage of MAX1090AEEI+T in mixed-voltage systems.

What is the maximum analog input voltage range for MAX1090AEEI+T in unipolar mode?

In unipolar mode, the MAX1090AEEI+T accepts analog inputs from 0V to VREF (i.e., 0V to +2.5V) when using the internal reference. The absolute input voltage range is GND to VDD (+5V), but for full-scale accuracy, inputs must stay within 0V to +2.5V (or –1.25V to +1.25V in bipolar mode). Exceeding VREF by more than 50mV risks degraded linearity, as specified in the Absolute Maximum Ratings table for MAX1090AEEI+T.