Analog Devices Inc./Maxim Integrated MAX1109CUB-T

Overview

The MAX1109CUB-T from Maxim Integrated is a low-power, 8-bit, dual-channel successive-approximation ADC with internal track/hold, +4.096V reference, SPI/QSPI/MICROWIRE-compatible 4-wire serial interface, and software-configurable unipolar/bipolar input modes. It operates from +4.5V to +5.5V, consumes 130µA at 50ksps, and supports VDD monitoring for battery-powered instrumentation.

For engineers reviewing the MAX1109CUB-T datasheet, MAX1109CUB-T pinout, MAX1109CUB-T application, or MAX1109CUB-T equivalent, key selection criteria include its 10-pin µMAX package, 50ksps conversion rate, ±0.5 LSB INL, internal 4.096V reference, and support for pseudo-differential analog inputs with COM-referenced acquisition.

Technical Context

The MAX1109CUB-T implements a charge-redistribution SAR architecture with integrated track/hold and auto-zero rail, enabling accurate single-supply operation without external hold capacitors. Its analog front-end supports eight software-selectable modes-including unipolar/bipolar, single-ended/pseudo-differential, and VDD monitoring-via a configurable 8-bit control byte.

Conversion timing is determined by either the internal 400kHz oscillator or an external clock (50–500kHz); acquisition time is fixed at 1µs at max clock rate. The REF pin accepts 1V to VDD external references or supplies the internal +4.096V reference, which exhibits ±50ppm/°C tempco and requires 1µF bypassing to GND.

Key Specifications

Pinout & Package

The MAX1109CUB-T is housed in a 10-pin µMAX package (3mm × 3mm, 0.5mm pitch), footprint compatible with industry-standard 10-lead µMAX devices and occupying only 20% of an 8-pin DIP area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, serial 8-bit ADC applications.

Compared with ADS7822U and MAX1110CUB+, the MAX1109CUB-T uniquely combines dual-channel capability, +4.5V to +5.5V operation, VDD monitoring, and software-configurable bipolar inputs in a 10-pin µMAX package-making it optimal for 5V industrial and portable instrumentation where channel count, supply robustness, and feature flexibility are critical.

Availability

MAX1109CUB-T 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 guaranteed traceable sourcing.

Supply support for MAX1109CUB-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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX1108/MAX1109 product line was designed for ultra-low-power, space-constrained measurement systems requiring dual-channel digitization, flexible input configuration, and integrated reference functionality-targeting portable instrumentation and remote sensing.

FAQ

What is the maximum sampling rate supported by the MAX1109CUB-T?

The MAX1109CUB-T supports up to 50ksps using either its internal 400kHz clock or an external clock ranging from 50kHz to 500kHz. Conversion time is 20µs in external clock mode at 500kHz and 35µs in internal clock mode. This rate is maintained across the full operating temperature range and supply voltage (4.5V–5.5V), with no missing codes guaranteed.

Does the MAX1109CUB-T require external components for basic operation?

The MAX1109CUB-T requires only a 1µF capacitor from REF to GND for stable internal reference operation and optional 0.1µF bypassing at COM for noise reduction. No external hold capacitor, reference IC, or level-shifting circuitry is needed-its integrated track/hold, +4.096V reference, and 3V/5V-tolerant digital interface enable direct connection to microcontrollers.

How does the VDD monitoring mode work in the MAX1109CUB-T?

In VDD monitoring mode, the MAX1109CUB-T internally routes the VDD supply to the analog input multiplexer, allowing direct digitization of the supply voltage without external resistive dividers. The resulting 8-bit code corresponds linearly to VDD across the 4.5V–5.5V range, enabling real-time battery health assessment in portable systems using the same ADC hardware.

What are the absolute maximum ratings for the analog input pins of the MAX1109CUB-T?

The CH0, CH1, and COM pins of the MAX1109CUB-T tolerate −0.3V to (VDD + 0.3V) continuously. However, for accurate conversion, input voltages must stay within GND − 50mV to VDD + 50mV. Exceeding these limits risks measurement error-even if within absolute ratings-due to diode conduction affecting reference stability and T/H acquisition.

Can the MAX1109CUB-T operate with an external reference voltage?

Yes, the MAX1109CUB-T accepts external reference voltages from 1V to VDD at the REF pin. When used, the internal +4.096V reference is disabled. External references must be stable to ±0.5LSB (±20mV for 4.096V full scale) during conversion; a 1µF bypass capacitor remains recommended to suppress noise coupling into the reference path.