Analog Devices Inc./Maxim Integrated MAX1395ETB+

Overview

The MAX1395ETB+ from Maxim Integrated is a 10-bit, single-supply, micropower successive-approximation register (SAR) analog-to-digital converter with dual single-ended analog inputs (AIN1/AIN2), 357ksps maximum throughput, ±0.5 LSB INL/DNL, and operation from +1.5V to +3.6V. It features SPI/QSPI/MICROWIRE/DSP-compatible 3-wire serial interface, external reference support (0.6V to VDD), and AutoShutdown™ between conversions - optimized for battery-powered portable dataloggers and medical instruments.

For engineers reviewing the MAX1395ETB+ datasheet, MAX1395ETB+ pinout, MAX1395ETB+ application, or MAX1395ETB+ equivalent, key selection considerations include its 2-channel single-ended input architecture, 3mm × 3mm 10-pin TDFN-EP package, -40°C to +85°C extended temperature range, and low-power operation down to 3.1µW at 1ksps - critical for space-constrained, energy-sensitive embedded systems.

Technical Context

The MAX1395ETB+ implements a switched-capacitor SAR architecture with integrated track-and-hold, supporting channel-selectable single-ended conversion via CH1/CH2 control. Its analog front-end accepts 0 to VREF input on either AIN1 or AIN2, with channel-to-channel offset matching of ±0.1 LSB and gain matching of ±0.1 LSB over temperature.

Conversion timing is synchronized to SCLK, requiring 14 clock cycles per result (4 leading zeros + 10 data bits, MSB-first), with acquisition completed on the 3rd falling edge of SCLK after CS assertion. The device enters AutoShutdown automatically after LSB output, reducing IDD to <1µA in power-down mode.

Key Specifications

Pinout & Package

MAX1395ETB+ is housed in a 3mm × 3mm, 10-pin TDFN-EP package with exposed pad (EP), rated for -40°C to +85°C operation. The EP is not internally connected and may be tied to GND or left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and AD7476ARTZ-REEL7, the MAX1395ETB+ uniquely combines dual single-ended inputs, 1.5V operation, AutoShutdown, and tight channel matching - making it the only option that eliminates external muxes while enabling ultra-low-power, battery-native designs.

Availability

MAX1395ETB+ is available at Aetrix Electronics and suitable for portable datalogging, medical instrumentation, battery-powered test equipment, and industrial process monitoring requiring stable component supply and long-term lifecycle support.

Supply support for MAX1395ETB+ 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 MAX1395ETB+ belongs to Maxim's micropower SAR ADC product line, engineered specifically for ultra-low-power, space-constrained, battery-operated systems where dual-channel sampling, wide supply range, and guaranteed linearity are essential.

FAQ

What is the maximum sample rate supported by the MAX1395ETB+?

The MAX1395ETB+ supports a maximum throughput rate of 357ksps, achieved with a 5MHz SCLK and 14-clock-cycle conversion sequence. At this rate, the device consumes 0.27mW at 1.8V. Lower sampling rates reduce power consumption proportionally - e.g., 3.1µW at 1ksps - thanks to AutoShutdown between conversions. This makes the MAX1395ETB+ highly adaptable across both high-speed burst capture and ultra-low-duty-cycle sensing applications.

How does the MAX1395ETB+ handle dual analog inputs?

The MAX1395ETB+ uses the CH1/CH2 pin (Pin 6) to select between AIN1 (Pin 3) and AIN2 (Pin 2). Pulling CH1/CH2 low activates AIN1; driving it high selects AIN2. Both inputs are single-ended, referenced to GND, with identical 0 to VREF range. Channel-to-channel offset and gain matching are specified at ±0.1 LSB, ensuring consistent scaling - a key advantage over external multiplexers that introduce mismatch and settling delays.

Can the MAX1395ETB+ operate directly from a single CR2032 lithium coin cell?

Yes, the MAX1395ETB+ operates from +1.5V to +3.6V, making it fully compatible with a fresh CR2032 (nominal 3.0V, down to ~2.0V at end-of-life). Its 1.5V minimum supply and 3.1µW idle power at 1ksps allow direct connection without voltage regulation. Combined with AutoShutdown, this enables multi-year operation in low-duty-cycle applications such as wireless sensor nodes or portable diagnostic tools powered solely by a coin cell.

What serial interface protocols does the MAX1395ETB+ support?

The MAX1395ETB+ supports SPI, QSPI, MICROWIRE, and DSP-compatible 3-wire serial interfaces. It uses a 14-cycle frame (4 leading zeros + 10 data bits, MSB-first) with data valid on SCLK falling edges. CS and OE can be tied together for standard SPI/QSPI operation, or OE can be held low for DSP-style continuous streaming. No mode pins or configuration registers are required - interface behavior is determined solely by host timing and pin states.

Does the MAX1395ETB+ require an external reference, and what are the constraints?

Yes, the MAX1395ETB+ requires an external reference applied to the REF pin (Pin 5), with voltage ranging from 0.6V to VDD + 0.05V. A 0.1µF bypass capacitor to GND is mandatory for stable operation. The reference defines the full-scale range: for example, a 1.25V reference yields 1.25V/1024 ≈ 1.22mV/LSB. Using a precision external reference (e.g., REF3012) enables ratiometric accuracy and eliminates drift associated with internal references.