Analog Devices Inc./Maxim Integrated MAX1281BCUP+T

Overview

MAX1281BCUP+T from Maxim Integrated is a 12-bit, 8-channel serial analog-to-digital converter (ADC) with integrated track/hold, multiplexer, and internal +2.5V reference. It operates from a single +2.7V to +3.6V supply, achieves 300ksps sampling rate, supports software-configurable unipolar/bipolar and single-ended/pseudo-differential inputs, and targets battery-powered data acquisition systems.

For engineers reviewing the MAX1281BCUP+T datasheet, MAX1281BCUP+T pinout, MAX1281BCUP+T application, or MAX1281BCUP+T equivalent, this page delivers verified electrical specs, real-world timing behavior, validated power-mode trade-offs, and precise analog input interface constraints - all confirmed for the MAX1281BCUP+T variant specifically.

Technical Context

The MAX1281BCUP+T uses successive-approximation register (SAR) architecture with an on-chip track/hold that acquires input signals in ≤625ns and completes conversion in 3.3µs at 4.8MHz SCLK. Its pseudo-differential input structure samples only the IN+ channel while requiring IN− to remain stable within ±0.5LSB during conversion.

It implements a 4-wire SPI/QSPI/MICROWIRE-compatible serial interface with CS, SCLK, DIN, and DOUT, plus dedicated SSTRB strobe for TMS320 DSP synchronization. Power management includes four software-selectable modes: normal (2.5mA), reduced-power (1.3mA), fast power-down (0.9mA), and full power-down (2µA), with automatic wake-up on CS assertion.

Key Specifications

Pinout & Package

MAX1281BCUP+T is housed in a 20-pin TSSOP package (4.4mm × 6.5mm, 0.65mm pitch) with exposed pad for thermal enhancement and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with ADS7822U and AD7490BRUZ, the MAX1281BCUP+T uniquely balances 300ksps performance, integrated +2.5V reference, SSTRB DSP strobe, and 2µA shutdown - making it optimal for compact, battery-sensitive 8-channel acquisition where timing determinism and supply simplicity are critical.

Availability

MAX1281BCUP+T is available at Aetrix Electronics and suitable for portable data logging, battery-powered instrumentation, and medical device development requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX1281BCUP+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 and mixed-signal ICs for demanding industrial, medical, and communications applications.

The MAX1280/MAX1281 product line delivers low-power, multi-channel SAR ADCs optimized for portable and battery-constrained systems requiring integrated references, flexible input configurations, and deterministic serial interfaces.

FAQ

What is the maximum sampling rate supported by the MAX1281BCUP+T?

The MAX1281BCUP+T supports a maximum sampling rate of 300ksps, achieved with a 4.8MHz serial clock and 16-clock conversion cycle. This rate is guaranteed across the full operating temperature range (0°C to +70°C) and supply range (+2.7V to +3.6V), with full-linear bandwidth extending to 250kHz and full-power bandwidth to 3MHz.

Does the MAX1281BCUP+T require an external reference voltage?

No, the MAX1281BCUP+T does not require an external reference voltage. It includes an internal +2.500V ±0.020V reference with ±15ppm/°C temperature coefficient. An external reference (1.0V to VDD1) may be used only if REFADJ is tied to VDD1 to disable the internal buffer - but for most portable applications, the internal reference is sufficient and simplifies design.

How does the pseudo-differential input mode work on the MAX1281BCUP+T?

In pseudo-differential mode, the MAX1281BCUP+T samples only the IN+ channel (e.g., CH0), while IN− (e.g., CH1) is held stable at a fixed voltage (typically COM or VREF/2). The conversion result represents the difference between IN+ and IN−, but IN− must remain within ±0.5LSB of its nominal value during acquisition and conversion - unlike true differential ADCs, it does not actively sample both inputs.

What are the power consumption values for each operating mode of the MAX1281BCUP+T?

The MAX1281BCUP+T offers four power modes: normal operation (2.5mA), reduced-power mode (1.3mA), fast power-down (0.9mA), and full power-down (2µA). These values are measured at VDD = 3.6V and include both analog and digital supply currents (IVDD1 + IVDD2). Full power-down is activated by setting PD1=PD0=0 in the control byte or asserting SHDN low.

Can the MAX1281BCUP+T interface directly with a TMS320 DSP without additional logic?

Yes, the MAX1281BCUP+T can interface directly with TMS320-family DSPs using its dedicated SSTRB (serial strobe) output. SSTRB pulses high for exactly one SCLK period immediately before the MSB of the 12-bit conversion result appears on DOUT, providing precise timing alignment for DSP-controlled data capture - no glue logic or FPGA delay compensation is required.