Analog Devices Inc./Maxim Integrated MAX1111EEE+

Overview

The MAX1111EEE+ from Maxim Integrated is a low-power, 8-bit, 4-channel analog-to-digital converter (ADC) with internal track/hold, 2.048V reference, and SPI/QSPI/MICROWIRE-compatible serial interface. It operates from a single 2.7V–5.5V supply, consumes only 85µA at 50ksps, supports software-configurable unipolar/bipolar and single-ended/differential inputs, and targets portable data logging and hand-held measurement devices.

For engineers reviewing the MAX1111EEE+ datasheet, MAX1111EEE+ pinout, MAX1111EEE+ application, or MAX1111EEE+ equivalent, key selection considerations include its 4-channel input flexibility, 50ksps sampling rate with internal clock, ±1 LSB total unadjusted error, 2.048V internal reference, and QSOP-16 package compatibility with space-constrained embedded sensor interfaces.

Technical Context

The MAX1111EEE+ uses successive-approximation (SAR) architecture with integrated track/hold circuitry and supports both internal clock (400kHz typical) and external serial-clock-driven conversion. Its analog front-end allows software-selectable single-ended (4 channels) or differential (2 channels) operation via an 8-bit control byte, with COM pin defining zero-code reference.

Conversion timing is tightly coupled to serial interface activity: in external clock mode, it completes within 10 SCLK cycles (e.g., 20µs at 500kHz); in internal clock mode, conversion takes 25µs (typ), with SSTRB providing end-of-conversion strobe. Input voltage range is programmable from 0V to VREFIN (unipolar) or ±VREFIN/2 (bipolar), referenced to AGND and COM.

Key Specifications

Pinout & Package

The MAX1111EEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), optimized for compact PCB layouts in battery-powered instrumentation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit multichannel ADC applications.

Compared with ADS7822U and MCP3204-I/P, the MAX1111EEE+ uniquely balances ultra-low power (6µA shutdown), integrated 2.048V reference, and flexible bipolar/single-ended configuration - making it optimal for space- and energy-constrained portable instrumentation where component count and supply headroom are critical.

Availability

MAX1111EEE+ is available at Aetrix Electronics and suitable for portable data logging, hand-held measurement devices, and medical instruments requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for MAX1111EEE+ 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, medical, and portable applications.

The MAX1111EEE+ belongs to Maxim's low-power serial ADC product line, engineered specifically for battery-operated instrumentation requiring high integration, minimal external components, and guaranteed DC accuracy over temperature.

FAQ

What is the maximum sampling rate supported by the MAX1111EEE+?

The MAX1111EEE+ supports up to 50ksps when using an external serial clock at 500kHz (10 clock cycles per conversion). In internal clock mode, the conversion time is fixed at 25µs (typ), enabling a theoretical maximum of ~40ksps - though effective throughput depends on host processor readout speed and interface overhead. The device guarantees performance across its full 2.7V–5.5V supply range and –40°C to +85°C operating temperature.

Does the MAX1111EEE+ include an internal voltage reference?

Yes, the MAX1111EEE+ integrates a precision 2.048V bandgap reference, specified from 1.968V to 2.128V over temperature and supply. This reference is available at the REFOUT pin and can be used directly at REFIN to set the full-scale input range. A 1µF capacitor is required between REFOUT and AGND for stability. External references from 1V to VDD are also supported via the REFIN pin.

How many analog input channels does the MAX1111EEE+ support, and how are they configured?

The MAX1111EEE+ provides four analog input channels (CH0–CH3), configurable in either single-ended mode (four independent inputs referenced to COM) or pseudo-differential mode (two differential pairs: CH0/CH1 and CH2/CH3). Configuration is controlled entirely by bits in the 8-bit serial control byte (SGL/DIF and SEL bits), with no hardware changes required. COM must remain stable to ±0.5 LSB for accurate zero-code alignment.

What power-saving features does the MAX1111EEE+ offer?

The MAX1111EEE+ offers dual power-down mechanisms: software-controlled (via PD bits in the control byte) reducing supply current to 6µA at 1ksps, and hardware-controlled via the SHDN pin (10µA max when pulled low). In software power-down, the device remains responsive to serial commands and wakes instantly upon interface access. The internal reference can be disabled independently by pulling SHDN high, further reducing system-level power in sleep states.

Is the MAX1111EEE+ compatible with standard microcontroller serial interfaces?

Yes, the MAX1111EEE+ is fully compatible with SPI, QSPI, and MICROWIRE protocols. It uses a 4-wire interface (CS, SCLK, DIN, DOUT) with MSB-first, falling-edge data output. For SPI, configure CPOL = 0 and CPHA = 0. All digital inputs (CS, SCLK, DIN) tolerate voltages up to 5.5V regardless of VDD, enabling seamless interfacing with both 3V and 5V microcontrollers without level-shifting circuitry.