Analog Devices Inc./Maxim Integrated MAX1108CUB+T

Overview

MAX1108CUB+T from Maxim Integrated is a low-power, 8-bit, dual-channel successive-approximation ADC with integrated track/hold, internal +2.048V reference, SPI/QSPI/MICROWIRE-compatible 4-wire serial interface, and software-configurable unipolar/bipolar input modes. It operates from +2.7V to +3.6V, draws only 105µA at 50ksps, and supports battery monitoring in portable data loggers and hand-held measurement devices.

For engineers reviewing the MAX1108CUB+T datasheet, MAX1108CUB+T pinout, MAX1108CUB+T application, or MAX1108CUB+T equivalent, this page delivers verified electrical specs (INL ±0.2 LSB, SINAD 49dB, tCONV 20µs), µMAX package mapping, validated pin functions, and two confirmed alternative ADCs for low-voltage, dual-channel 8-bit sampling in space-constrained embedded systems.

Technical Context

The MAX1108CUB+T employs a charge-redistribution SAR architecture with an on-chip track/hold that acquires signals in ≤1µs and holds them during conversion. Its flexible control byte configures input mode (single-ended/pseudo-differential), reference source (internal +2.048V or external 1V–VDD), and clock source (internal 400kHz oscillator or external 50–500kHz).

Conversion timing is tightly coupled to the serial clock: in external-clock mode, each conversion requires exactly 10 SCLK cycles (e.g., 20µs at 500kHz); in internal-clock mode, conversion completes in 35µs independent of SCLK. The DOUT output is three-state, synchronized to SCLK falling edges, and compatible with 3V microcontrollers without level-shifting.

Key Specifications

Pinout & Package

The MAX1108CUB+T is housed in a 10-pin µMAX package (3mm × 3mm, 0.5mm pitch), occupying only 20% of an 8-pin DIP footprint-ideal for ultra-compact PCB layouts in handheld medical instruments and wearables.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1108CUB+T, ADS7822U trades ultra-low power for speed and flexibility, while TLV2548IDW adds channel count and performance at the cost of size and current-making MAX1108CUB+T optimal for compact, long-life, dual-input sensing where 50ksps suffices.

Availability

MAX1108CUB+T is available at Aetrix Electronics and suitable for portable data logging, hand-held measurement devices, and solar-powered remote systems requiring stable component supply, guaranteed traceability, and lifecycle continuity.

Supply support for MAX1108CUB+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 consumer applications.

The MAX1108CUB+T belongs to Maxim's precision low-power ADC product line, designed specifically for battery-operated instrumentation where minimal current draw, small footprint, and integrated references reduce system complexity and bill-of-materials cost.

FAQ

What is the operating temperature range for the MAX1108CUB+T?

The MAX1108CUB+T is specified for commercial temperature operation from 0°C to +70°C, as indicated by the "C" suffix in the ordering code. This range covers indoor portable instruments, handheld test equipment, and consumer-grade medical devices where ambient conditions remain controlled. The device maintains full DC accuracy (±0.2 LSB INL, ±0.2 LSB offset) and dynamic performance (49dB SINAD) across this interval without derating.

Does the MAX1108CUB+T require external components for basic operation?

Yes, the MAX1108CUB+T requires a 1µF capacitor from REF to GND to stabilize the internal +2.048V reference, and a 0.1µF capacitor from VDD to GND for supply decoupling. No external hold capacitor, reference buffer, or level-shifters are needed-the µMAX package integrates all core analog functions, enabling a minimal 4-component solution (two caps + two bypass caps) for dual-channel 8-bit conversion.

How does the MAX1108CUB+T handle bipolar input signals?

The MAX1108CUB+T supports true bipolar conversion via pseudo-differential mode: when configured with COM referenced to VREF/2, the device outputs twos-complement codes where 0x00 = –VREF/2, 0x80 = 0V, and 0xFF = +VREF/2 – 1LSB. This allows direct digitization of AC-coupled sensor outputs (e.g., accelerometer signals) without external op-amp level-shifting, provided COM remains stable within ±0.5LSB during conversion.

Can the MAX1108CUB+T interface directly with a 3.3V microcontroller SPI port?

Yes, the MAX1108CUB+T's digital interface is fully compatible with 3.3V SPI systems: DIN, SCLK, and CS accept logic-high thresholds down to 0.7×VDD (≥2.1V at 3V supply), and DOUT drives VOH ≥ VDD – 0.5V (≥2.5V) and VOL ≤ 0.4V-meeting standard SPI voltage levels without level translation. Configure the MCU's SPI peripheral with CPOL = 0 and CPHA = 0 for correct timing alignment.

What is the maximum source impedance supported for accurate acquisition on CH0 or CH1?

The MAX1108CUB+T's input tracking circuit specifies RIN = 6.5kΩ and CHOLD = 18pF, yielding a minimum acquisition time tACQ = 6(RS + RIN) × 18pF. For full 8-bit accuracy at 500kHz SCLK (1µs tACQ), source impedance RS must not exceed 2.7kΩ. Higher impedances (e.g., 10kΩ) require reducing SCLK frequency to ≥200kHz to maintain ≤1LSB error-verified in the device's Typical Operating Characteristics plots.