Analog Devices Inc./Maxim Integrated MAX189ACPA

Overview

MAX189ACPA 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 3-wire SPI/QSPI/MICROWIRE-compatible interface. It features an internal track/hold, 4.5MHz small-signal bandwidth, and operates in 0°C to +70°C industrial temperature range - ideal for isolated data acquisition and portable sensor interfaces where precision, low power, and compact layout are critical.

For engineers reviewing the MAX189ACPA datasheet, MAX189ACPA pinout, MAX189ACPA application, or MAX189ACPA equivalent, this page delivers verified electrical parameters, package-specific terminal roles, real-world use-value per application, and two confirmed alternative parts with documented functional and selection differences - all grounded in Maxim's official MAX187/MAX189 datasheet Rev 1 (3/12).

Technical Context

The MAX189ACPA implements a successive-approximation register (SAR) architecture with integrated track/hold, requiring no external hold capacitor. Conversion is initiated by CS falling edge, with end-of-conversion signaled by DOUT high transition; data is clocked out MSB-first on SCLK falling edges, requiring ≥13 cycles for full 12-bit output plus leading EOC bit.

It accepts unipolar analog inputs from 0V to VREF (2.5V to VDD), supports external reference voltages up to +5.25V, and uses a 4.7µF bypass capacitor at REF when paired with precision external references. Shutdown mode reduces supply current to ≤10µA, with wake-up time dependent on external reference discharge characteristics.

Key Specifications

Pinout & Package

MAX189ACPA is packaged in an 8-pin plastic DIP (PDIP) with through-hole mounting and 0.3-inch body width. Pin functions are electrically identical to the SO variant but mapped to 8 pins; unused SO pins (AGND, DGND, N.C.) are omitted.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7816U and AD7892BRZ-1, the MAX189ACPA uniquely balances low-power shutdown, flexible reference support, and minimal pin count in an 8-pin DIP - making it optimal for space-constrained, battery-aware, or retrofit industrial designs where 75ksps suffices.

Availability

MAX189ACPA is available at Aetrix Electronics and suitable for portable data logging, isolated data acquisition, and high-accuracy process control requiring stable component supply, long-term manufacturability, and consistent parametric performance across production lots.

Supply support for MAX189ACPA 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing markets.

The MAX187/MAX189 product line was designed specifically for low-power, space-constrained data acquisition systems requiring 12-bit precision, serial interface simplicity, and robust operation across industrial temperature ranges - with the MAX189ACPA targeting cost-sensitive, external-reference-based implementations.

FAQ

What is the reference voltage requirement for MAX189ACPA?

The MAX189ACPA requires an external reference voltage applied to the REF pin, ranging from +2.5V to VDD (4.75V–5.25V). It does not include an internal reference - unlike the MAX187 - so a stable, low-noise external source (e.g., REF5025 or LT1019) with ≤10Ω output impedance and ≥0.1µF local bypass is mandatory for specified accuracy. The MAX189ACPA datasheet confirms 4.096V is the typical reference used for full-scale 12-bit resolution.

Does MAX189ACPA support SPI, QSPI, and MICROWIRE interfaces?

Yes, the MAX189ACPA serial interface is explicitly compatible with SPI, QSPI, and MICROWIRE standards as stated in the Maxim datasheet. It uses three wires (CS, SCLK, DOUT), requires CPOL=0/CPHA=0 for SPI, and outputs data MSB-first on SCLK falling edges. No mode pins or configuration registers are needed - compatibility is inherent in timing and protocol behavior, verified across all three standards in application notes.

What is the maximum sampling rate of MAX189ACPA?

The MAX189ACPA achieves a guaranteed 75ksps (75,000 samples per second) throughput rate under standard conditions: VDD = +5V ±5%, f_CLK = 4.0MHz, unipolar input, and TA = 0°C to +70°C. This is enabled by its 8.5-clock-cycle conversion time and 1.5µs track/hold acquisition. The datasheet specifies this rate applies to both MAX189ACPA and MAX189BCPA variants within their respective grade temperature ranges.

How does shutdown mode work on MAX189ACPA?

Shutdown mode on MAX189ACPA is activated by pulling the SHDN pin low, reducing supply current to ≤10µA. The device remains fully functional upon SHDN deassertion, with wake-up time dependent on external reference stability - typically sub-microsecond since no internal reference charging is required. Unlike the MAX187, the MAX189ACPA has no internal reference to stabilize, enabling faster reactivation for burst-mode sampling.

What package type is MAX189ACPA supplied in?

The MAX189ACPA is supplied in an 8-pin plastic dual in-line package (PDIP) with 0.3-inch width, lead finish Sn/Pb, and RoHS-compliant option available. This package matches the pinout shown in Figure 3a of the MAX187/MAX189 datasheet Rev 1, and is distinct from the 16-pin wide SO variant - which includes separate AGND/DGND pins and N.C. pads not present in the PDIP version.