Analog Devices Inc./Maxim Integrated MAX1294ACEI+

Overview

MAX1294ACEI+ from Maxim Integrated is a 12-bit, 420ksps successive-approximation ADC with internal +2.5V reference, 6-channel single-ended/3-channel pseudo-differential analog input multiplexer, and parallel 12-bit interface. It operates from a single +5V supply, consumes 2.8mA at full speed, and supports software-configurable unipolar/bipolar operation - ideal for portable data-acquisition systems requiring low power and compact footprint.

For engineers reviewing the MAX1294ACEI+ datasheet, MAX1294ACEI+ pinout, MAX1294ACEI+ application, or MAX1294ACEI+ equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in patient monitoring and energy management, and two validated alternative parts with documented functional and application differences.

Technical Context

The MAX1294ACEI+ implements a charge-redistribution SAR architecture with integrated track/hold (6MHz full-power bandwidth), on-chip clock generator, and programmable acquisition mode (internal or external). Its analog front-end supports six single-ended channels or three pseudo-differential pairs, with COM-referenced zero-code alignment and ±0.5 LSB INL over temperature.

Control is executed via an 8-bit configuration byte (D7–D0) that sets channel address (A2–A0), SGL/DIF, UNI/BIP, ACQMOD, and PD1/PD0 power-down modes. The parallel interface uses tri-state D0–D11 outputs, active-low CS/WR/RD, and open-drain INT with automatic deassertion on read or new write.

Key Specifications

Pinout & Package

MAX1294ACEI+ is housed in a 28-pin QSOP package with exposed pad (not thermally enhanced), rated for surface-mount reflow assembly. Pin 1 is marked by a dot; pin numbering follows standard counter-clockwise convention from top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1295ACEI+, the MAX1294ACEI+ provides higher dynamic range (+67dB SINAD vs. +62dB) and native +5V compatibility; versus ADS7822U, it delivers 4× resolution, parallel throughput, and integrated reference - critical for precision data-acquisition where code density and timing determinism matter.

Availability

MAX1294ACEI+ is available at Aetrix Electronics and suitable for industrial process monitoring, patient vital sign acquisition, energy metering subsystems, and touchscreen controller interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX1294ACEI+ 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 MAX1294ACEI+ belongs to Maxim's high-speed, low-power SAR ADC product line - engineered specifically for portable and space-constrained data-acquisition systems needing accuracy, integration, and minimal external components.

FAQ

What is the maximum sampling rate of the MAX1294ACEI+ and under what conditions is it achieved?

The MAX1294ACEI+ achieves a maximum sampling rate of 420ksps when operating with its internal 6MHz clock in internal acquisition mode and configured for unipolar single-ended input. This rate assumes VDD = +5V ±10%, TA = +25°C, and proper 4.7µF bypass at the REF pin. At lower clock frequencies or in external acquisition mode, the effective rate decreases due to added setup/hold overhead.

Does the MAX1294ACEI+ require an external reference, or does it include an internal one?

The MAX1294ACEI+ includes a precision +2.5V internal bandgap reference with ±20ppm/°C temperature coefficient and ±100mV adjustment range via the REFADJ pin. An external reference may be used by connecting REF to the external source and REFADJ to VDD, but the internal reference is fully functional and eliminates the need for external components in most applications.

How many analog input channels does the MAX1294ACEI+ support, and how are they configured?

The MAX1294ACEI+ supports six analog input channels (CH0–CH5) in single-ended mode or three pseudo-differential pairs (CH0/CH1, CH2/CH3, CH4/CH5) selected via the SGL/DIF bit and A2–A0 address bits. Channel selection is software-configurable through the 8-bit control byte written to the device during each conversion setup.

What power-down modes are available on the MAX1294ACEI+, and what are their typical current draws?

The MAX1294ACEI+ offers two software-selectable power-down modes: Standby mode draws <2µA and retains register state, while Full Power-Down mode draws <2µA and resets internal logic. Both are activated via PD1/PD0 bits in the control byte. In normal operation at 420ksps, supply current is 2.8mA; at 10ksps, it drops to 400µA.

Is the MAX1294ACEI+ pin-compatible with other devices in the MAX129x family?

Yes - the MAX1294ACEI+ shares identical pinout and package (28-pin QSOP) with MAX1294BCEI+, MAX1294AEEI+, and MAX1294BEEI+. It is not pin-compatible with the MAX1296 series (24-pin QSOP) or the +3V MAX1295/MAX1297 variants, though those share functional equivalence and register mapping for software portability.