Analog Devices Inc./Maxim Integrated MAX1280BCUP

Overview

The MAX1280BCUP from Maxim Integrated is a 12-bit, 400ksps serial analog-to-digital converter with integrated 8-channel multiplexer, track/hold, and internal +2.5V reference. It operates from a single +4.5V to +5.5V supply, supports software-configurable unipolar/bipolar and single-ended/pseudo-differential inputs, and delivers ±1 LSB INL over 0°C to +70°C - ideal for portable data loggers requiring precision, low power, and compact footprint.

For engineers reviewing the MAX1280BCUP datasheet, MAX1280BCUP pinout, MAX1280BCUP application, or MAX1280BCUP equivalent, key selection considerations include its 20-pin TSSOP package, SPI/QSPI/MICROWIRE-compatible 4-wire interface, 2.5mA active supply current at 400ksps, shutdown current under 2µA, and support for pseudo-differential channel pairs (CH0/CH1, CH2/CH3, etc.) in battery-constrained systems.

Technical Context

The MAX1280BCUP uses successive-approximation register (SAR) architecture with an on-chip track/hold that acquires input signals in ≤468ns. Its analog front end accepts inputs from GND to VDD1, with COM referenced to ground for single-ended zero-code alignment and stable ±0.5LSB return-side voltage required during conversion in pseudo-differential mode.

Conversion is clocked by an external SCLK (up to 6.4MHz), requiring 16 clock cycles per sample. The device implements four software-selectable power modes - normal, reduced-power, fast power-down, and full power-down - with automatic wake-up via serial interface access and turn-on time sufficient for inter-conversion shutdown at reduced sampling rates.

Key Specifications

Pinout & Package

MAX1280BCUP is housed in a 20-pin thin shrink small-outline package (TSSOP) with exposed pad, optimized for thermal performance and PCB space efficiency in portable instrumentation.

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 MAX1280BCUP offers optimal balance of integrated features (multiplexer, track/hold, reference), compact 20-pin TSSOP packaging, and ultra-low 2µA shutdown current - making it uniquely suited for space- and energy-constrained portable instrumentation where feature integration reduces total solution size and validation effort.

Availability

MAX1280BCUP is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply, RoHS-compliant packaging, and guaranteed 0°C to +70°C industrial temperature operation.

Supply support for MAX1280BCUP 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 MAX1280BCUP belongs to Maxim's high-speed, low-power SAR ADC product line, engineered specifically for portable and battery-operated systems where integration of multiplexer, track/hold, reference, and serial interface reduces system-level complexity and bill-of-materials cost.

FAQ

What is the maximum sampling rate supported by the MAX1280BCUP?

The MAX1280BCUP supports a maximum sampling rate of 400ksps, achieved with a 6.4MHz serial clock and 16-clock conversion cycle. This rate is specified under conditions of VDD1 = VDD2 = +4.5V to +5.5V, fSCLK = 6.4MHz, and bipolar input mode. At lower clock frequencies or in reduced-power modes, the effective sampling rate decreases proportionally while maintaining 12-bit resolution and ±1 LSB INL performance.

Does the MAX1280BCUP require an external reference voltage?

No, the MAX1280BCUP does not require an external reference voltage because it integrates a precision +2.500V ±0.8% internal reference with ±1.5% adjustment range via the REFADJ pin. An external reference (1V to VDD1) may be used only if the internal reference buffer is disabled by pulling REFADJ to VDD1 - a configuration validated in the MAX1280BCUP datasheet for specialized ratiometric or high-accuracy applications.

How does the pseudo-differential input mode work on the MAX1280BCUP?

The MAX1280BCUP implements pseudo-differential input mode by selecting complementary channel pairs (CH0/CH1, CH2/CH3, CH4/CH5, CH6/CH7) where only the positive input (IN+) is actively sampled while the negative input (IN-) remains stable at COM or a fixed reference. During conversion, IN- must stay within ±0.5LSB of its setpoint to maintain accuracy; this architecture avoids true differential amplifiers but enables noise rejection in matched-sensor applications like thermocouple or bridge measurements.

What power-saving features does the MAX1280BCUP offer beyond shutdown mode?

Beyond the hardware SHDN pin, the MAX1280BCUP provides four software-selectable power modes: normal (2.5mA), reduced-power (1.3mA), fast power-down (0.9mA), and full power-down (2µA). Entering any power-down mode automatically disables the internal reference and track/hold; serial interface access wakes the device within microseconds, enabling inter-conversion shutdown without sacrificing responsiveness - a key advantage for duty-cycled sensor acquisition in the MAX1280BCUP.

Is the MAX1280BCUP pin-compatible with other devices in the MAX128x family?

Yes, the MAX1280BCUP is pin-compatible with the MAX1280BEUP, MAX1281BCUP, and MAX1281BEUP - all share identical 20-pin TSSOP footprints and pin functions. However, voltage ranges differ: MAX1280 variants operate from +4.5V to +5.5V, while MAX1281 variants use +2.7V to +3.6V. Interchangeability requires verifying supply rail compatibility, timing specifications (e.g., 6.4MHz vs. 4.8MHz SCLK), and temperature grade requirements before substitution in existing MAX1280BCUP designs.