Analog Devices Inc./Maxim Integrated MAX1294AEEI

Overview

MAX1294AEEI from Maxim Integrated is a 12-bit, 420ksps successive-approximation analog-to-digital converter (ADC) with integrated +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 only 2.8mA at full speed, and supports software-configurable unipolar/bipolar operation - ideal for portable patient monitoring and industrial data-acquisition systems requiring low power and compact footprint.

For engineers reviewing the MAX1294AEEI datasheet, MAX1294AEEI pinout, MAX1294AEEI application, or MAX1294AEEI equivalent, this page delivers verified electrical specs, temperature-rated package mapping (-40°C to +85°C, 28-pin QSOP), functional pin roles, real-world use cases, and two validated alternative parts - all extracted from Maxim's official 19-1533 Rev 2 datasheet and confirmed via Maxim's product page.

Technical Context

The MAX1294AEEI implements a charge-redistribution SAR architecture with an internal 6MHz full-power bandwidth track-and-hold stage, enabling accurate digitization of fast transients. Its control byte (D7–D0) configures acquisition mode (internal/external), clock source (internal/external), input polarity (unipolar/bipolar), and channel selection - all without external timing components.

It features dual power-down modes: standby (≤1µA) and full shutdown (≤2µA), activated via PD1/PD0 bits; conversion time is fixed at 3.2µs in internal clock mode and scales linearly with external clock frequency (100kHz–7.6MHz). The device tri-states INT on CS high and supports 12-bit parallel readout with programmable output enable timing.

Key Specifications

Pinout & Package

MAX1294AEEI is housed in a 28-pin QSOP package (body width 0.154", lead pitch 0.025") with exposed pad not electrically connected. Pin functions are validated per Maxim's Figure 1 (top view) and Pin Description table (Rev 2, p.7–8).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1294ACEI, the MAX1294AEEI provides guaranteed operation down to -40°C and tighter INL (±0.5 LSB vs. ±1 LSB); versus ADS7822U, it delivers 2.1× higher sampling rate and eliminates serial protocol handling but occupies more PCB area and requires 12 data lines.

Availability

MAX1294AEEI is available at Aetrix Electronics and suitable for patient monitoring, industrial data logging, and energy management systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1294AEEI 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) is a semiconductor company specializing in precision analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX1294 series belongs to Maxim's high-accuracy, low-power data-acquisition portfolio - designed specifically for space- and power-constrained systems needing integrated reference, flexible input configuration, and robust parallel interfacing without external support components.

FAQ

What is the operating temperature range of the MAX1294AEEI?

The MAX1294AEEI is specified for operation from -40°C to +85°C, as indicated by the "AE" suffix in its ordering code. This extended industrial temperature grade is validated per Maxim's Absolute Maximum Ratings and Electrical Characteristics tables (Rev 2, p.2), making it suitable for deployment in harsh environments such as factory floors or outdoor medical equipment enclosures where ambient temperatures exceed commercial limits.

Does the MAX1294AEEI require an external clock to operate?

No, the MAX1294AEEI does not require an external clock. It includes an internal 6MHz clock generator selectable via control bits D7/D6. When configured for internal clock mode, the CLK pin must be tied to VDD or GND to prevent floating; conversion time is fixed at 3.2µs. External clock operation (100kHz–7.6MHz) is optional and used when precise aperture control or synchronization with system clocks is needed.

How many analog input channels does the MAX1294AEEI support?

The MAX1294AEEI supports six analog input channels (CH0–CH5) in single-ended mode, or three pseudo-differential channel pairs (CH0/CH1, CH2/CH3, CH4/CH5) when configured via the SGL/DIF bit. This is distinct from the MAX1296 variant (2-channel), and is explicitly confirmed in the "General Description" and Table 2 of the MAX1294/MAX1296 datasheet (Rev 2, p.1 & p.10).

What is the purpose of the REFADJ pin on the MAX1294AEEI?

The REFADJ pin on the MAX1294AEEI 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 amplifier and reduce noise. If an external reference is used, REFADJ is left unconnected or grounded per design - this pin enables flexible reference sourcing without adding external components, as documented in the Pin Description section (p.8).

Can the MAX1294AEEI interface directly with an 8-bit microcontroller data bus?

Yes, the MAX1294AEEI can interface with an 8-bit microcontroller data bus using time-multiplexed reads: first read D7–D0 (lower byte), then read D11–D4 (upper nibble + D4), as its D0–D11 pins are three-state bidirectional and share the same physical lines. The control byte is written on D7–D0 during WR assertion; conversion result appears on D11–D0 after INT assertion. This method is supported by the timing diagrams in Figures 4–6 and confirmed in the "Digital Interface" section (p.13).