Analog Devices Inc./Maxim Integrated MAX147BCAP+T

Overview

MAX147BCAP+T from Maxim Integrated is a 12-bit, 8-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, and SPI/QSPI/MICROWIRE-compatible 4-wire serial interface. It operates from a single +2.7V to +5.25V supply, requires an external reference, and delivers 133ksps conversion rate with ±0.5 LSB INL and 73dB SINAD - used in portable data loggers and battery-powered medical instruments.

For engineers reviewing the MAX147BCAP+T datasheet, MAX147BCAP+T pinout, MAX147BCAP+T application, or MAX147BCAP+T equivalent, key selection criteria include its 20-pin SSOP package, external reference dependency, shutdown current of 1µA, and compatibility with TMS320-family DSPs via SSTRB strobe output.

Technical Context

The MAX147BCAP+T employs successive-approximation architecture with an internal track/hold circuit that acquires input signals within 1.5µs and supports pseudo-differential sampling across eight analog inputs. Its serial interface operates in external clock mode (up to 2MHz) or internal clock mode, with control-byte programming for channel selection, input polarity, and power-down states.

It features a reference-buffer amplifier with ±1.5% REFADJ adjustment range, accepts external VREF from 1.0V to (VDD + 50mV), and provides SSTRB strobe synchronized to conversion start/end - enabling direct interfacing with TI TMS320-series DSPs without glue logic.

Key Specifications

Pinout & Package

MAX147BCAP+T 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 AD7490BRUZ, MAX147BCAP+T uniquely balances ultra-low shutdown current (1µA), external reference support, and TMS320-compatible SSTRB - making it optimal for portable, DSP-coupled, and calibration-critical applications where power and timing determinism are co-priorities.

Availability

MAX147BCAP+T is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical instruments, and industrial process monitoring requiring stable component supply and long-term manufacturability.

Supply support for MAX147BCAP+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 demanding industrial, medical, and communications applications.

The MAX146/MAX147 family was engineered for low-power, high-accuracy data acquisition in portable and battery-operated systems - emphasizing flexible input configuration, minimal external components, and seamless microprocessor/DSP interfacing.

FAQ

What is the reference voltage requirement for MAX147BCAP+T?

The MAX147BCAP+T requires an external reference voltage applied to the VREF pin, typically 2.500V. Unlike the MAX146, it does not include an internal reference. The reference must be stable and capable of driving the reference buffer input, with voltage range specified from 1.0V to (VDD + 50mV). For best performance, a low-noise, temperature-stable reference such as the MAX6126 is recommended. The MAX147BCAP+T reference buffer is disabled by tying REFADJ to VDD.

Does MAX147BCAP+T support differential input mode?

Yes, MAX147BCAP+T supports pseudo-differential input mode via software configuration. When SGL/DIF = 0 in the control byte, it pairs CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7 as differential channel sets. In this mode, the device samples the voltage difference between the selected pair, with the negative input (IN−) required to remain stable to ±0.5 LSB relative to AGND. This capability enables direct connection to bridge sensors and thermocouples without external instrumentation amplifiers.

What is the function of the SSTRB pin on MAX147BCAP+T?

The SSTRB (Serial Strobe) pin on MAX147BCAP+T provides hardware timing synchronization for external processors. In external clock mode, SSTRB pulses high for one SCLK period just before the MSB of the 12-bit conversion result is shifted out on DOUT. This signal allows TMS320-family DSPs to precisely align data capture without software polling or tight timing margins. SSTRB is high-impedance when CS is high, supporting multi-device serial bus configurations.

How does the SHDN pin operate on MAX147BCAP+T?

The SHDN pin on MAX147BCAP+T implements three distinct operating states: pulling SHDN low enables full power-down (1µA supply current); letting SHDN float configures the reference buffer for external compensation (required when using external reference); and pulling SHDN high enables internal compensation mode. This three-level control eliminates need for external logic to manage reference stability and power state transitions - simplifying firmware and reducing system-level component count.

Can MAX147BCAP+T interface directly with SPI microcontrollers?

Yes, MAX147BCAP+T is fully compatible with standard SPI interfaces when configured with CPOL = 0 and CPHA = 0. It uses a 4-wire SPI-compatible protocol (CS, SCLK, DIN, DOUT) with MSB-first data transfer. The control byte is clocked in on SCLK rising edges, and conversion results are clocked out on falling edges. No level-shifting or protocol translation is needed for 3.3V or 5V microcontrollers - enabling plug-and-play integration with STM32, PIC, or NXP Kinetis families.