Analog Devices Inc./Maxim Integrated MAX1284BCSA+T

Overview

MAX1284BCSA+T from Maxim Integrated is a 12-bit serial analog-to-digital converter (ADC) with internal +2.5V reference, single +4.5V to +5.5V supply operation, ±1 LSB INL/DNL accuracy, and 400 ksps sampling rate. It integrates a high-bandwidth track/hold circuit and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface, targeting space- and power-constrained data acquisition in portable medical instruments and remote sensor nodes.

For engineers reviewing the MAX1284BCSA+T datasheet, MAX1284BCSA+T pinout, MAX1284BCSA+T application, or MAX1284BCSA+T equivalent, this page delivers verified electrical specs, validated pin functions, confirmed use cases in battery-powered instrumentation, and two rigorously cross-checked alternative ADCs with documented functional and parametric distinctions.

Technical Context

The MAX1284BCSA+T employs a successive-approximation register (SAR) architecture with an internal capacitive DAC and auto-zeroed comparator. Its track/hold stage acquires signals within 468 ns and supports full-power bandwidth up to 6 MHz, enabling undersampling of transient events beyond Nyquist.

Conversion is initiated by CS falling edge and clocked by external SCLK (up to 6.4 MHz); output is unipolar 12-bit MSB-first serial data preceded by three leading zeros, synchronized to SCLK rising edges with 80 ns valid delay and 10 ns hold time.

Key Specifications

Pinout & Package

MAX1284BCSA+T is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and lead(Pb)-free, with 1.27 mm pitch and standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1284BCSA+T, ADS7822U trades sampling speed and integrated reference for broader supply flexibility, while MAX11131AUT+T offers superior linearity and speed in 3.3 V domains but lacks 5 V compatibility and uses a non-interchangeable 2.048 V reference-making MAX1284BCSA+T the optimal choice for existing 5 V, space-constrained, reference-integrated designs.

Availability

MAX1284BCSA+T is available at Aetrix Electronics and suitable for portable data logging, battery-powered instrumentation, and medical device applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX1284BCSA+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 systems.

The MAX1284/MAX1285 product line was designed for low-power, space-constrained data acquisition where integration of reference, track/hold, and serial interface eliminates external components and simplifies PCB layout.

FAQ

What is the maximum sampling rate supported by the MAX1284BCSA+T?

The MAX1284BCSA+T achieves a maximum sampling rate of 400 ksps under specified conditions: VDD = +4.5 V to +5.5 V, fSCLK = 6.4 MHz, and 16 clock cycles per conversion. This rate is enabled by its internal track/hold with 468 ns acquisition time and optimized SAR architecture. At lower clock frequencies or higher supply temperatures, the effective rate may decrease slightly due to timing margin constraints.

Does the MAX1284BCSA+T require an external reference voltage?

No, the MAX1284BCSA+T does not require an external reference voltage because it integrates a factory-trimmed +2.50 V ±10 mV reference connected to the REF pin. This internal reference drives both the ADC's conversion core and can be used externally-provided it is bypassed with a 4.7 µF capacitor. Using the internal reference eliminates calibration drift and reduces component count versus external solutions.

Can the MAX1284BCSA+T interface directly with a 3.3 V microcontroller SPI port?

Yes, the MAX1284BCSA+T can interface directly with a 3.3 V microcontroller SPI port when operated at VDD = +5 V, because its digital inputs (CS, SCLK, SHDN) accept VIH ≥ 3.0 V and VIL ≤ 0.8 V, satisfying 3.3 V logic thresholds. However, DOUT output high level is VOH ≥ 4 V (at ISOURCE = 1 mA), so a series resistor or level shifter may be needed if the µP input cannot tolerate 5 V signals.

What is the purpose of the SHDN pin on the MAX1284BCSA+T?

The SHDN (shutdown) pin on the MAX1284BCSA+T is an active-low control that reduces supply current from 2.5 mA (active) to 2 µA (typical) when pulled low. This feature enables ultra-low-power operation in battery-powered systems during idle periods. Exiting shutdown requires ~2 ms for the internal 4.7 µF REF capacitor to recharge before accurate conversions resume-timing must be accounted for in firmware sequencing.

How does the MAX1284BCSA+T handle analog input protection?

The MAX1284BCSA+T includes internal ESD protection diodes that clamp the AIN pin to GND and VDD, allowing safe operation with input voltages from (GND − 0.3 V) to (VDD + 0.3 V). If the analog input exceeds these limits by more than 50 mV, external current limiting (≤2 mA) is required to prevent damage. This protection enables robust interfacing with sensors prone to overvoltage transients without added discrete clamping components.