Analog Devices Inc./Maxim Integrated MAX147AEAP

Overview

The MAX147AEAP from Maxim Integrated is a 12-bit, 8-channel serial analog-to-digital converter (ADC) with software-configurable unipolar/bipolar and single-ended/differential inputs, operating from a single +2.7V to +5.25V supply. It integrates an on-chip track/hold, SPI/QSPI/MICROWIRE-compatible 4-wire serial interface, and supports external reference input. It delivers 133ksps conversion rate, ±1 LSB INL, and 73dB SINAD - ideal for portable data loggers and battery-powered medical instruments.

For engineers reviewing the MAX147AEAP datasheet, MAX147AEAP pinout, MAX147AEAP application, or MAX147AEAP equivalent, key selection considerations include its external-reference architecture, 20-pin SSOP package, shutdown current of 1µA, and compatibility with TMS320-family DSPs via SSTRB strobe output.

Technical Context

The MAX147AEAP uses successive-approximation (SAR) architecture with integrated track/hold circuitry, acquiring input signals in ≤1.5µs. Its analog front-end supports pseudo-differential sampling across eight channels, with COM pin serving as common-mode reference for both single-ended and differential modes.

It operates exclusively with external reference voltage applied at VREF (2.500V typical), requiring REFADJ tied to VDD to disable the internal reference buffer. Serial communication uses MSB-first, falling-edge clocked DOUT with configurable control-byte format defining channel, polarity, mode, and clock/power-down selection.

Key Specifications

Pinout & Package

MAX147AEAP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, optimized for compact PCB layouts in space-constrained portable equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131ETE+, the MAX147AEAP uniquely combines external reference flexibility, 8-channel multiplexing, and TMS320-compatible strobe output - making it optimal for portable, multi-sensor, battery-aware systems requiring metrology-grade accuracy and long runtime.

Availability

MAX147AEAP is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply and long-term industrial availability.

Supply support for MAX147AEAP 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 MAX146/MAX147 product line targets low-power, high-accuracy data acquisition in resource-constrained environments - emphasizing single-supply operation, software configurability, and minimal external components.

FAQ

What is the reference voltage requirement for MAX147AEAP?

The MAX147AEAP requires an external 2.500V reference applied to the VREF pin. Unlike the MAX146, it has no internal reference; the internal reference buffer must be disabled by tying REFADJ to VDD. This architecture ensures reference stability independent of supply voltage, critical for precision measurements across varying battery levels in portable systems using MAX147AEAP.

Does MAX147AEAP support differential input mode?

Yes, MAX147AEAP supports pseudo-differential input mode via software configuration. When SGL/DIF = 0 in the control byte, it samples four differential pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. The negative input (IN−) must remain stable to ±0.5LSB relative to AGND during conversion - achieved by bypassing the selected IN− channel with a 0.1µF capacitor to AGND. This mode is implemented in MAX147AEAP hardware and verified in its timing diagrams and channel tables.

What is the minimum acquisition time for MAX147AEAP?

The guaranteed maximum acquisition time (tACQ) for MAX147AEAP is 1.5µs under all conditions, defined as the time required for the track/hold circuit to settle within ½ LSB. This value is specified in the Electrical Characteristics table and confirmed in Figure 1 of the datasheet. It applies regardless of input source impedance below 1kΩ, and forms the lower bound for inter-conversion delay when operating at full 133ksps rate in MAX147AEAP systems.

How does the SHDN pin function on MAX147AEAP?

The SHDN pin on MAX147AEAP provides three-level control: pulled low for full shutdown (1µA), floated for external reference compensation mode, or pulled high for internal compensation mode. This pin directly controls the reference buffer amplifier's feedback configuration - a unique feature documented in the Pin Description section. For MAX147AEAP, floating SHDN is required when using external compensation capacitors at REFADJ, ensuring optimal reference stability.

Is MAX147AEAP compatible with SPI microcontrollers?

Yes, MAX147AEAP is fully compatible with standard SPI interfaces when configured with CPOL = 0 and CPHA = 0. Its 4-wire serial interface (CS, SCLK, DIN, DOUT) operates with MSB-first, falling-edge data capture, matching SPI Mode 0 timing. The datasheet explicitly confirms SPI/QSPI/MICROWIRE compatibility, and the control-byte protocol - including START bit detection and idle-state behavior - is validated for seamless integration with ARM Cortex-M, PIC, and other SPI-capable MCUs using MAX147AEAP.