Analog Devices Inc./Maxim Integrated MAX1295AEEI+

Overview

MAX1295AEEI+ from Maxim Integrated is a low-power, 12-bit successive-approximation ADC with internal +2.5V reference, 265ksps sampling rate, 6-channel single-ended / 3-channel pseudo-differential analog input multiplexer, and parallel 12-bit interface. It operates from a single +2.7V to +3.6V supply and delivers ±0.5 LSB INL over –40°C to +85°C, making it suitable for battery-powered patient monitoring and industrial data-acquisition systems.

For engineers reviewing the MAX1295AEEI+ datasheet, MAX1295AEEI+ pinout, MAX1295AEEI+ application, or MAX1295AEEI+ equivalent, key selection considerations include its software-configurable unipolar/bipolar input mode, fast 2µs wake-up from shutdown, tri-state INT output, internal track/hold with 3MHz full-power bandwidth, and QSOP-28 package compatibility with legacy +3V data-acquisition designs.

Technical Context

The MAX1295AEEI+ implements a SAR architecture with integrated track/hold, supporting both internal and external clock modes via control bits D6/D7, and internal/external acquisition modes controlled by ACQMOD (D5). Its analog front-end enables six single-ended or three pseudo-differential input configurations, with COM referenced zero-code alignment and ±0.5 LSB stability requirement during conversion.

Conversion timing is deterministic: 13 clock cycles per conversion, with tCONV = 3.3 µs (typ) at 4.8MHz clock; aperture jitter is <50 ps in external acquisition mode. The device uses a 12-bit capacitive DAC and charge redistribution technique, with input protection diodes allowing analog inputs to swing from (GND – 300mV) to (VDD + 300mV), though accurate full-scale operation requires (GND – 50mV) to (VDD + 50mV).

Key Specifications

Pinout & Package

MAX1295AEEI+ is housed in a 28-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), optimized for space-constrained PCB layouts while maintaining thermal performance up to +85°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11607ETE+, the MAX1295AEEI+ provides higher resolution, faster parallel throughput, and flexible analog input configuration - critical for real-time embedded systems requiring deterministic timing and minimal µP intervention.

Availability

MAX1295AEEI+ is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical devices, energy metering subsystems, and touchscreen controller interfaces requiring stable component supply across extended temperature ranges.

Supply support for MAX1295AEEI+ 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 and mixed-signal ICs for demanding industrial, medical, and communications applications.

The MAX1295AEEI+ belongs to Maxim's low-power, high-accuracy SAR ADC product line, engineered specifically for battery-operated and space-constrained data-acquisition systems needing integrated reference, flexible input routing, and µP-friendly parallel interface.

FAQ

What is the operating temperature range of the MAX1295AEEI+?

The MAX1295AEEI+ is rated for –40°C to +85°C, meeting extended industrial temperature requirements. This range is confirmed in the Ordering Information table and validated across all electrical specifications including INL (±0.5 LSB), supply current, and reference voltage stability. The device maintains full functionality and specified performance throughout this range without derating.

Does the MAX1295AEEI+ require an external clock to operate?

No - the MAX1295AEEI+ supports both internal and external clock modes. When configured for internal clock mode (D7=1, D6=0), it generates its own 3MHz conversion clock, eliminating the need for external timing components. The CLK pin must be tied high or low in this mode to prevent floating. External clock operation (D7=1, D6=1) accepts 100kHz–4.8MHz TTL/CMOS signals.

How many analog input channels does the MAX1295AEEI+ support in single-ended mode?

The MAX1295AEEI+ supports six analog input channels (CH0–CH5) in single-ended mode, as explicitly defined in Table 2 of the datasheet and confirmed in the General Description. Channel selection is performed via A2–A0 address bits in the control byte, and COM serves as the common reference node for all inputs.

What is the function of the REFADJ pin on the MAX1295AEEI+?

The REFADJ pin on the MAX1295AEEI+ serves as the bandgap reference buffer input. When using the internal +2.5V reference, REFADJ must be connected to VDD to disable the internal bandgap buffer and stabilize the reference output. When using an external reference, REFADJ is left unconnected or tied to VDD per datasheet guidance, and a 0.01µF capacitor is required from REFADJ to GND.

Can the MAX1295AEEI+ interface directly with a 16-bit microprocessor data bus?

Yes - the MAX1295AEEI+ features a 12-bit three-state parallel interface (D0–D11) with CS, WR, RD, and INT signals fully compatible with standard 16-bit µP buses. Its output data format is binary in unipolar mode and two's complement in bipolar mode, and all control and data signals meet TTL/CMOS voltage thresholds, enabling direct connection without level-shifting or glue logic.