Analog Devices Inc./Maxim Integrated MAX1111EEE/V+

Overview

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

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

Technical Context

The MAX1111EEE/V+ uses successive-approximation (SAR) architecture with an integrated track/hold circuit and supports both internal (400kHz typ) and external (50kHz–2MHz) clock modes. Its analog front-end allows software-selectable unipolar or bipolar operation and single-ended (4 channels) or differential (2 channels) input configurations via an 8-bit control byte.

Conversion results are output in MSB-first format on DOUT synchronized to SCLK falling edges; SSTRB provides end-of-conversion strobe signaling. The device features automatic power-down (6µA at 1ksps) triggered by software or SHDN pin, and accepts digital inputs up to 5.5V independent of VDD.

Key Specifications

Pinout & Package

The MAX1111EEE/V+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), optimized for compact PCB layouts in portable electronics.

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/V+ uniquely combines internal 2.048V reference, bipolar input support, and 6µA shutdown-making it optimal for ultra-low-power, feature-flexible portable instrumentation where BOM reduction and input mode adaptability are prioritized.

Availability

MAX1111EEE/V+ is available at Aetrix Electronics and suitable for portable data logging, hand-held measurement devices, and medical instruments requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MAX1111EEE/V+ 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/V+ belongs to Maxim's low-power serial ADC product line, engineered specifically for battery-operated instrumentation where integration, power efficiency, and interface simplicity are critical design constraints.

FAQ

What is the maximum sampling rate of the MAX1111EEE/V+ and how is it achieved?

The MAX1111EEE/V+ achieves a maximum sampling rate of 50ksps using its internal 400kHz clock or an external clock up to 2MHz. In external clock mode, 10 SCLK cycles complete one conversion (including acquisition and SAR decision phases). At 500kHz SCLK, this yields 50ksps. The internal clock mode fixes conversion time at ~25µs, enabling deterministic timing independent of host processor clock speed. This makes the MAX1111EEE/V+ suitable for time-critical sensor acquisition in portable systems.

Does the MAX1111EEE/V+ support differential input mode, and how is it configured?

Yes, the MAX1111EEE/V+ supports pseudo-differential input mode across two channel pairs: CH0/CH1 and CH2/CH3. Configuration is done via bit SGL/DIF (bit 2) in the 8-bit control byte: setting it to '0' selects differential mode. In this mode, the device samples the voltage difference between the selected pair while referencing the negative input to AGND-stable COM. The output is unipolar (0–255) for positive differences or zero for negative inputs unless bipolar mode is also enabled. This structure enables noise-rejecting measurements without external instrumentation amplifiers.

What is the function of the SHDN pin on the MAX1111EEE/V+, and what are its three states?

The SHDN pin on the MAX1111EEE/V+ provides three-level control: high-impedance (default) enables normal operation; pulled to DGND reduces supply current to ≤10µA for deep shutdown; pulled to VDD disables the internal 2.048V reference while keeping digital logic active. This flexibility allows system-level power management-e.g., disabling the reference during standby while preserving register state. Unlike simple on/off shutdown, this three-state behavior supports hybrid power architectures where reference stability and digital readiness must be independently controlled.

Can the MAX1111EEE/V+ interface directly with a 3.3V microcontroller SPI peripheral?

Yes, the MAX1111EEE/V+ can interface directly with a 3.3V microcontroller SPI peripheral. Its DIN, SCLK, and CS inputs tolerate voltages up to 5.5V regardless of VDD, so 3.3V logic levels are safely recognized. DOUT and SSTRB outputs swing rail-to-rail (0V to VDD), so with VDD = 3.3V, they produce clean 3.3V-compatible signals. No level-shifting circuitry is needed. Additionally, the device supports CPOL = 0 and CPHA = 0 SPI mode, matching standard microcontroller SPI master configurations without custom timing adjustments.

What is the purpose of the COM pin on the MAX1111EEE/V+, and how must it be handled in layout?

The COM pin on the MAX1111EEE/V+ serves as the zero-reference point for single-ended analog inputs and the common-mode node for pseudo-differential measurements. It must remain stable to within ±0.5 LSB (≈4mV for 2.048V reference) during conversion to maintain accuracy. In layout, COM should be connected to a quiet analog ground plane with minimal trace length, isolated from noisy digital return paths. A dedicated 0.1µF ceramic capacitor from COM to AGND is recommended to suppress high-frequency noise, especially when driving high-impedance sources. Failure to stabilize COM degrades INL and offset performance.