Analog Devices Inc./Maxim Integrated MAX1293BCEG

Overview

MAX1293BCEG from Maxim Integrated is a 12-bit, 250ksps successive-approximation ADC with integrated +2.5V reference, software-configurable 4-channel single-ended or 2-channel pseudo-differential analog input, and byte-wide parallel (8+4) interface. It operates from a single +3V analog supply and supports digital logic levels from +1.8V to +3.6V via VLOGIC. Designed for low-power data acquisition, it delivers ±0.5 LSB INL and 67dB SINAD in battery-powered patient monitoring systems.

For engineers reviewing the MAX1293BCEG datasheet, MAX1293BCEG pinout, MAX1293BCEG application, or MAX1293BCEG equivalent, key selection criteria include its 24-pin QSOP package, internal track/hold with 3MHz full-power bandwidth, dual power-down modes (<2µA shutdown current), unipolar/bipolar input configuration, and compatibility with microprocessor parallel buses requiring minimal external components.

Technical Context

The MAX1293BCEG implements a charge-redistribution SAR architecture with an integrated track/hold stage, supporting both internal and external clock modes (100kHz–4.8MHz). Its analog front-end allows software-selectable unipolar/bipolar and single-ended/pseudo-differential operation using a configurable 4:1 analog multiplexer.

Conversion timing is precisely controlled via WR/CS/RD handshaking, with interrupt-driven readout (INT active-low) and high-byte enable (HBEN) for 12-bit result multiplexing across an 8-bit data bus. Power management includes two software-selectable power-down modes-standby (10µA) and full shutdown (2µA)-activated between conversions without disrupting interface timing.

Key Specifications

Pinout & Package

MAX1293BCEG is housed in a 24-pin QSOP package (5.3mm × 7.6mm, 0.65mm pitch), optimized for space-constrained PCB layouts in handheld instrumentation and wearable sensors.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and AD7490BRUZ, MAX1293BCEG uniquely combines 12-bit accuracy, parallel microprocessor interface, VLOGIC voltage flexibility (+1.8V to +3.6V), and integrated reference in a 24-pin QSOP-making it optimal for space- and power-constrained embedded systems requiring rapid, deterministic data capture without firmware overhead.

Availability

MAX1293BCEG is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical diagnostics, energy metering subsystems, and touch-screen controller interfaces requiring stable component supply across extended production lifecycles.

Supply support for MAX1293BCEG 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, emphasizing integration, low power, and reliability.

The MAX1293BCEG belongs to Maxim's low-power SAR ADC product line, engineered specifically for battery-operated and space-constrained data-acquisition systems requiring high accuracy without external support components.

FAQ

What is the operating temperature range for MAX1293BCEG?

The MAX1293BCEG is specified for commercial temperature operation from 0°C to +70°C. This range is confirmed in the Ordering Information table of the official datasheet, where the "C" grade suffix (as in MAX1293BCEG) explicitly denotes the 0°C to +70°C ambient rating. The device maintains full electrical performance-including ±0.5 LSB INL and 250ksps sampling-across this entire range without derating.

Does MAX1293BCEG support pseudo-differential input mode, and how many channels does it provide?

Yes, MAX1293BCEG supports pseudo-differential input mode via software configuration (SGL/DIF = 0 in control byte). In this mode, it provides two independent differential channel pairs: CH0/CH1 and CH2/CH3. Each pair measures the voltage difference between its two inputs, with CH0 or CH2 serving as the sampled positive input and CH1 or CH3 held stable as the reference return-enabling noise-rejecting measurements without a true differential front-end.

Can MAX1293BCEG interface directly with a +1.8V microcontroller?

Yes, MAX1293BCEG can interface directly with a +1.8V microcontroller by connecting the VLOGIC pin to +1.8V. Its digital I/O pins (D0–D7, RD, WR, CS, INT, HBEN) are fully compliant with +1.8V logic thresholds: VIH = 0.5V and VIL = 1.5V at VLOGIC = 1.8V, per Electrical Characteristics Table. No level-shifting circuitry is required, simplifying interconnect and reducing component count.

What is the minimum acquisition time required before conversion starts in MAX1293BCEG?

The minimum acquisition time (tACQ) for MAX1293BCEG is 3.2µs, as specified in the Electrical Characteristics table under "Track/Hold Acquisition Time". This value applies under typical conditions (VDD = +3V, TA = +25°C) and assumes source impedance ≤3kΩ. For higher source impedances, tACQ increases per the formula tACQ = 9(RS + 800Ω) × 12pF, requiring additional settling time before WR assertion to avoid missing codes.

How does the HBEN pin function during data readout of MAX1293BCEG?

The HBEN (High Byte Enable) pin on MAX1293BCEG controls multiplexing of the 12-bit conversion result onto the 8-bit data bus: when HBEN = 1, D0–D3 carry bits D8–D11 (MSBs); when HBEN = 0, D0–D7 carry bits D0–D7 (LSBs). This allows standard 8-bit microprocessors to read the full 12-bit result in two consecutive cycles without requiring wider data paths or external latches-reducing system complexity and PCB routing density.