Analog Devices Inc./Maxim Integrated MAX147BEAP+T

Overview

MAX147BEAP+T 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 up to 133ksps conversion rate. It is used in portable data loggers and battery-powered medical instruments where low power and flexible input configuration are critical.

For engineers reviewing the MAX147BEAP+T datasheet, MAX147BEAP+T pinout, MAX147BEAP+T application, or MAX147BEAP+T equivalent, key selection criteria include its external reference requirement, 20-pin SSOP package, ±1 LSB INL, 73dB SINAD at 10kHz, and shutdown current of 1µA - all verified for industrial-temperature operation (–40°C to +85°C).

Technical Context

The MAX147BEAP+T uses successive-approximation architecture with a capacitive DAC and internal track/hold circuitry. Its analog front-end supports pseudo-differential sampling via CH0–CH7 multiplexer, with COM as common-mode reference; differential pairs are CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7.

It operates in either internal clock mode (self-timed conversion) or external clock mode (SCLK-driven), with configurable power-down states including full power-down (1µA) and fast power-down (54µA at 1ksps). The reference buffer is disabled by tying REFADJ to VDD, requiring an external 2.500V reference applied to VREF.

Key Specifications

Pinout & Package

MAX147BEAP+T is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, optimized for compact PCB layouts and automated assembly.

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, MAX147BEAP+T uniquely balances wide supply range (2.7–5.25V), external reference flexibility, and ultra-low 1µA shutdown current - making it optimal for cost-sensitive, battery-operated industrial sensors where reference sourcing is already established.

Availability

MAX147BEAP+T is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, battery-powered test equipment, and industrial process monitoring requiring stable component supply across extended temperature ranges.

Supply support for MAX147BEAP+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) designs precision analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX146/MAX147 product line delivers low-power, multi-channel SAR ADCs optimized for battery-operated and space-constrained systems requiring flexible input configuration and minimal external components.

FAQ

What is the reference configuration requirement for MAX147BEAP+T?

The MAX147BEAP+T requires an external 2.500V reference applied to the VREF pin. Its internal reference buffer must be disabled by connecting REFADJ to VDD. This differs from the MAX146 variant, which provides an internal 2.5V reference. Using an external reference ensures stability and accuracy across the full –40°C to +85°C temperature range specified for the MAX147BEAP+T.

Does MAX147BEAP+T support differential input mode, and how is it configured?

Yes, MAX147BEAP+T supports true differential input mode across four pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. Configuration is performed via the 8-bit control byte written to DIN: set SGL/DIF = 0 (bit 2), then select the pair using SEL2–SEL0 (bits 6–4). In differential mode, the device samples the voltage difference while maintaining COM as the stable reference node - critical for rejecting common-mode noise in medical and industrial sensing.

What is the minimum acquisition time for MAX147BEAP+T, and how does source impedance affect it?

The guaranteed minimum acquisition time (tACQ) for MAX147BEAP+T is 1.5µs. However, actual acquisition time increases with analog source impedance (RS) per tACQ = 9 × (RS + 9kΩ) × 16pF. For sources >1kΩ, a 0.01µF capacitor at each input is recommended to maintain accuracy. This behavior directly impacts sampling rate planning in high-impedance sensor interfaces like thermocouples or pH electrodes.

How does the SHDN pin function in MAX147BEAP+T, and what are its three states?

The SHDN pin on MAX147BEAP+T provides three distinct operational states: pulled low → full shutdown (1µA); pulled high → internal compensation mode (reference buffer enabled with fixed gain); floating → external compensation mode (reference buffer enabled with ±1.5% adjustability via REFADJ). This triple-state control allows precise power management and reference tuning without additional GPIOs - a key advantage in resource-constrained microcontroller systems using MAX147BEAP+T.

Can MAX147BEAP+T interface directly with a TMS320-series DSP, and what signal enables that?

Yes, MAX147BEAP+T interfaces directly with TMS320-family DSPs using the SSTRB (serial strobe) output. In internal clock mode, SSTRB asserts low at conversion start and high at completion; in external clock mode, it pulses high for one SCLK period before the MSB is clocked out on DOUT. This strobe synchronizes DSP DMA transfers without software polling, reducing CPU overhead and jitter in real-time control loops using MAX147BEAP+T.