Analog Devices Inc./Maxim Integrated MAX1081BEUP+T

Overview

MAX1081BEUP+T from Maxim Integrated is a 10-bit, 300ksps serial analog-to-digital converter with integrated 8-channel multiplexer, track/hold, and internal +2.5V reference. It operates from a single +2.7V to +3.6V supply, supports software-configurable unipolar/bipolar and single-ended/pseudo-differential inputs, and delivers ±0.5 LSB INL and 60dB SINAD for precision data acquisition in battery-powered medical instruments.

For engineers reviewing the MAX1081BEUP+T datasheet, MAX1081BEUP+T pinout, MAX1081BEUP+T application, or MAX1081BEUP+T equivalent, this page provides verified electrical specs, real-world timing constraints (e.g., 4.8MHz max SCLK, 625ns tACQ), power-mode behavior (2µA FULLPD), and confirmed alternative parts for portable instrumentation and process control designs.

Technical Context

The MAX1081BEUP+T uses successive-approximation architecture with an on-chip track/hold and 8:1 analog multiplexer. Its pseudo-differential input structure samples only the positive channel (IN+) while referencing the negative side (IN−) to COM or paired channels - requiring IN− stability within ±0.5 LSB during conversion.

It implements a 4-wire SPI/QSPI/MICROWIRE-compatible serial interface with SSTRB strobe for TMS320 DSP synchronization and supports four software-selectable power modes: normal (2.5mA), REDP (1.3mA), FASTPD (0.9mA), and FULLPD (2µA), with automatic wake-on-CS activation.

Key Specifications

Pinout & Package

MAX1081BEUP+T is housed in a 20-pin TSSOP package (4.4mm × 6.5mm, 0.65mm pitch) with exposed pad for thermal enhancement. Pin functions are validated per Maxim's official datasheet Rev 0 (19-1685).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit serial ADC applications.

Compared with ADS7822U and MAX11100ETE+, the MAX1081BEUP+T uniquely balances 300ksps speed, integrated adjustable reference, four power modes, and pseudo-differential flexibility - making it optimal for compact, battery-constrained systems requiring rapid channel switching and minimal external components.

Availability

MAX1081BEUP+T is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered instruments requiring stable component supply across industrial temperature ranges (-40°C to +85°C).

Supply support for MAX1081BEUP+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, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX1080/MAX1081 family targets low-power, multi-channel data acquisition systems where integration of mux, T/H, reference, and serial interface reduces solution size and design complexity.

FAQ

What is the maximum serial clock frequency supported by MAX1081BEUP+T?

The MAX1081BEUP+T supports a maximum serial clock (SCLK) frequency of 4.8MHz, as specified in its electrical characteristics table under VDD1 = +2.7V to +3.6V conditions. Operating above this limit risks timing violations and invalid conversion results. The device requires a 40–60% duty cycle and guarantees proper operation down to 0.5MHz for ultra-low-power applications. All timing parameters - including tCP (208ns), tCL (83ns), and tCH (83ns) - are validated at this 4.8MHz maximum.

Does MAX1081BEUP+T support true differential input mode?

No, the MAX1081BEUP+T implements pseudo-differential input architecture: only the positive input (IN+) is actively sampled by the track/hold circuit, while the negative input (IN−) is held stable during conversion. In pseudo-differential mode, IN− is selected from CH0/CH1, CH2/CH3, CH4/CH5, or CH6/CH7 pairs, but the device does not simultaneously sample both sides. True differential sampling would require independent T/H on both inputs - a capability absent in MAX1081BEUP+T.

How does the internal reference of MAX1081BEUP+T behave across temperature?

The internal reference of MAX1081BEUP+T exhibits ±15ppm/°C temperature coefficient, resulting in ±0.375mV drift over the full -40°C to +85°C range (based on 2.500V nominal). Typical operating curves (Figure MAX1080/1-10) confirm output remains within 2.4988V to 2.5005V across temperature. This stability meets requirements for portable instrumentation where calibration intervals exceed six months, eliminating need for periodic reference trimming.

Can MAX1081BEUP+T operate with an external reference voltage?

Yes, MAX1081BEUP+T supports external reference voltages from 1.0V to VDD1 by disabling its internal reference buffer - achieved by connecting REFADJ to VDD1. When using external reference, the REF pin becomes a high-impedance input accepting the external source, and the internal 2.5V generator is powered down. This configuration maintains full DC accuracy (±3.0 LSB gain error) and dynamic performance (60dB SINAD), provided the external reference exhibits ≤10µVp-p noise and ≤10ppm/°C drift.

What is the acquisition time (tACQ) specification for MAX1081BEUP+T?

The MAX1081BEUP+T specifies a minimum track/hold acquisition time (tACQ) of 625ns, measured from the falling SCLK edge after the eighth control-bit to the start of conversion. This value assumes source impedance ≤4kΩ and accounts for internal capacitance (12pF) and input resistance (800Ω). For higher source impedances, tACQ increases linearly per tACQ = 7 × (RS + 800Ω) × 12pF - requiring design verification if RS exceeds 2kΩ to avoid missing codes or INL degradation.