Analog Devices Inc./Maxim Integrated MAX189BCWE

Overview

MAX189BCWE from Maxim Integrated is a 12-bit, single-supply +5V serial analog-to-digital converter (ADC) with external reference input, 75ksps throughput, ±½ LSB integral nonlinearity (A-grade), and SPI/QSPI/MICROWIRE-compatible 3-wire interface - used in isolated data acquisition systems requiring precision, low power, and compact footprint.

For engineers reviewing the MAX189BCWE datasheet, MAX189BCWE pinout, MAX189BCWE application, or MAX189BCWE equivalent, this page delivers verified electrical specs, package mapping to 16-pin wide SO, functional pin roles, real-world use cases in high-accuracy process control and remote DSP, and two validated alternative ADCs with documented technical and application differences.

Technical Context

The MAX189BCWE implements a successive-approximation register (SAR) architecture with integrated track/hold, accepting unipolar 0V to V_REF analog inputs and digitizing at 75ksps using an external clock up to 5MHz. Its conversion sequence is initiated by CS falling edge, with end-of-conversion signaled by DOUT high.

It operates exclusively with an external reference voltage (2.5V to V_DD), requires no internal reference buffer enablement, and supports shutdown mode with ≤10µA supply current. Timing is governed by strict SCLK/CS setup/hold requirements including t_ACQ = 1.5µs and t_CONV = 5.5–8.5µs.

Key Specifications

Pinout & Package

MAX189BCWE is packaged in a 16-pin wide SO (Small Outline) surface-mount package with exposed pad (not thermally enhanced per datasheet), pin-compatible with MAX187 variants but functionally distinct due to external-reference-only operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131AUT+, the MAX189BCWE uniquely combines +5V operation, external reference support, 75ksps throughput, and ≤10µA shutdown - making it optimal for industrial +5V systems requiring calibrated multi-channel reference distribution and long-term power efficiency.

Availability

MAX189BCWE is available at Aetrix Electronics and suitable for portable data logging, isolated data acquisition, remote DSP, and high-accuracy process control applications requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for MAX189BCWE 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 fabless semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, automotive, and communications markets.

The MAX187/MAX189 family was designed for low-power, space-constrained data acquisition systems requiring 12-bit precision, serial interfacing, and robust operation across commercial and extended temperature grades.

FAQ

What is the reference voltage requirement for MAX189BCWE?

The MAX189BCWE requires an external reference voltage applied to the REF pin, ranging from +2.5V to V_DD (+5.25V max). It does not include an internal reference buffer. For optimal accuracy, a stable 4.096V source with ≤10Ω output impedance and 0.1µF local bypass is recommended. The MAX189BCWE specification assumes V_REF = 4.096V in all key AC/DC performance metrics.

Does MAX189BCWE support SPI, QSPI, and MICROWIRE interfaces?

Yes, the MAX189BCWE's 3-wire serial interface is fully compatible with SPI (CPOL = 0, CPHA = 0), QSPI, and MICROWIRE standards. It uses CS, SCLK, and DOUT lines with MSB-first unipolar output format. DOUT transitions on SCLK's falling edge, and data is clocked into the host on the rising edge - matching standard SPI timing conventions without additional level-shifting or protocol adaptation.

What is the maximum sampling rate and corresponding Nyquist frequency for MAX189BCWE?

The MAX189BCWE achieves a guaranteed 75ksps throughput rate, resulting in a Nyquist frequency of 37.5kHz. This allows accurate digitization of sinusoidal inputs up to 37.5kHz in baseband applications. For higher-frequency signals, undersampling techniques may be employed, provided anti-alias filtering is implemented - as confirmed by its 4.5MHz small-signal bandwidth and 8V/µs slew rate.

How does shutdown mode operate on MAX189BCWE?

Shutdown mode on MAX189BCWE is activated by pulling the SHDN pin low, reducing supply current to ≤10µA. Unlike the MAX187, SHDN has no reference-enable function - the MAX189BCWE always uses an external reference. Wake-up time is negligible since no internal reference capacitor charging is required; conversion can begin immediately after SHDN is deasserted and CS is pulsed.

What package type and pin count does MAX189BCWE use?

The MAX189BCWE is supplied in a 16-pin wide SO (Small Outline) package with 1.27mm lead pitch and 0.3-inch body width. Pinout matches the 16-pin SO variant of the MAX187 family, but functionality differs - notably REF is input-only and SHDN does not enable internal reference. This package provides better thermal dissipation and lower parasitic inductance than the 8-pin PDIP option.