Analog Devices Inc./Maxim Integrated MAX1392ETB+T

Overview

The MAX1392ETB+T from Maxim Integrated is a 10-bit, true-differential SAR analog-to-digital converter operating from +1.5V to +3.6V supply, delivering 357ksps throughput with ±0.5 LSB INL and 61dB SINAD at 85kHz input frequency. It features AutoShutdown™ between conversions, external reference support (0.6V to VDD), and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - optimized for portable battery-powered data acquisition in medical instruments and process control systems.

For engineers reviewing the MAX1392ETB+T datasheet, MAX1392ETB+T pinout, MAX1392ETB+T application, or MAX1392ETB+T equivalent, key selection criteria include its single true-differential input channel, unipolar/bipolar mode select via UNI/BIP pin, 10-pin TDFN-EP package with exposed pad, and ultra-low power consumption down to 3.1µW at 1ksps - critical for space-constrained, low-voltage embedded sensing designs.

Technical Context

The MAX1392ETB+T employs a track-and-hold circuit followed by a successive-approximation register (SAR) core, with conversion initiated on CS falling edge and sampling completed on the third SCLK falling edge. Its differential input architecture supports ±VREF/2 bipolar or 0–VREF unipolar ranges, with common-mode rejection of ±0.1 mV/V and full-power bandwidth of 4MHz.

Timing is tightly controlled: conversion time is fixed at 2.2µs (11 clock cycles), total throughput is 357ksps (14 SCLK cycles per conversion), and DOUT outputs MSB-first with 4 leading zeros. The device enters AutoShutdown automatically after LSB clock-out on the 13th SCLK falling edge, reducing quiescent current to <1µA.

Key Specifications

Pinout & Package

MAX1392ETB+T is housed in a 3mm × 3mm, 10-pin TDFN-EP package with exposed pad (not internally connected; recommended to tie to GND). Pin functions are validated per Maxim's official pin description table and functional diagram.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with ADS8860IDRCT and AD7920BRMZ-REEL, the MAX1392ETB+T uniquely balances true-differential input, 1.5V operation, sub-1mW active power, and integrated AutoShutdown - making it the only viable option for compact, long-life, low-voltage portable instrumentation where 10-bit resolution meets system requirements.

Availability

MAX1392ETB+T is available at Aetrix Electronics and suitable for portable datalogging, medical instruments, battery-powered instruments, and process control applications requiring stable component supply across extended temperature (-40°C to +85°C) and long-term production continuity.

Supply support for MAX1392ETB+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 MAX1392ETB+T belongs to Maxim's micropower SAR ADC product line, engineered specifically for ultra-low-voltage, battery-operated data-acquisition systems where size, power, and differential input integrity are primary constraints.

FAQ

What is the minimum supply voltage supported by the MAX1392ETB+T?

The MAX1392ETB+T operates down to +1.5V, enabling direct connection to two fresh alkaline/NiMH cells (≈3.0V) or a single CR2032 lithium coin cell (nominal 3.0V, discharging to ~2.0V). At 1.5V, it maintains full 357ksps throughput and specified DC accuracy (±0.5 LSB INL), making it ideal for unregulated battery systems where DC-DC converters would add cost and complexity.

How does the UNI/BIP pin affect the output data format of the MAX1392ETB+T?

When UNI/BIP is driven high, the MAX1392ETB+T operates in unipolar mode and outputs straight binary data (0x000 to 0x3FF) corresponding to input voltages from 0 to VREF. When pulled low, it switches to bipolar mode and outputs two's-complement data (0x200 to 0x3FF for positive, 0x000 to 0x1FF for negative), representing inputs from –VREF/2 to +VREF/2 - essential for AC-coupled sensor interfaces.

Can the MAX1392ETB+T interface directly with an SPI master without level-shifting?

Yes - the MAX1392ETB+T digital inputs (CS, SCLK, OE, UNI/BIP) accept logic thresholds defined as 0.3×VDD (low) and 0.7×VDD (high), and outputs (DOUT) drive VOH ≥ 0.9×VDD and VOL ≤ 0.1×VDD at 2mA load. This ensures native compatibility with 1.8V or 3.3V SPI masters when VDD matches the host I/O voltage, eliminating external level shifters.

What is the purpose of the exposed pad on the MAX1392ETB+T TDFN package?

The exposed pad on the MAX1392ETB+T is not internally connected but serves thermal and grounding functions. Maxim recommends connecting it to the PCB's analog ground plane to improve heat dissipation and reduce ground bounce. Doing so lowers junction temperature rise and enhances dynamic performance (e.g., SINAD stability) - especially critical during sustained 357ksps operation.

Does the MAX1392ETB+T require an external reference, and what are the voltage limits?

Yes - the MAX1392ETB+T requires an external reference applied to the REF pin, with valid range from 0.6V to (VDD + 0.05V). This allows scaling from low-noise bandgap references (e.g., 1.25V) up to the supply rail itself. A 0.1µF ceramic capacitor must be placed directly between REF and GND to stabilize the reference and maintain ±0.5 LSB INL performance across temperature and frequency.