Analog Devices Inc./Maxim Integrated MAX1268BCEG+

Overview

MAX1268BCEG+ from Maxim Integrated is a 12-bit, 420ksps successive-approximation ADC with integrated +2.5V reference, single +5V supply operation, and 2-channel single-ended / 1-channel pseudo-differential analog input configuration. It features software-configurable unipolar/bipolar mode, 2.8mA active current at full speed, and fast 2µs wake-up from shutdown - ideal for portable patient monitoring and industrial data-logging systems requiring low power and compact size.

For engineers reviewing the MAX1268BCEG+ datasheet, MAX1268BCEG+ pinout, MAX1268BCEG+ application, or MAX1268BCEG+ equivalent, this page delivers verified electrical specifications, validated QSOP-24 package mapping, confirmed timing behavior (tCONV = 3.6µs), real-world input multiplexing constraints, and two rigorously cross-checked alternative parts - all extracted from Maxim's official 19-2722 Rev 0 datasheet and validated against ordering information.

Technical Context

The MAX1268BCEG+ implements a charge-redistribution SAR architecture with an internal 6MHz full-power bandwidth track-and-hold stage, enabling accurate digitization of transients up to 350kHz linear bandwidth. Its control byte (D7–D0) configures acquisition mode (internal/external), clock source (internal/external), power-down state (full/standby), input polarity (unipolar/bipolar), and channel selection (CH0/CH1 or CH0–CH1 differential pair).

Conversion timing is deterministic: 13 clock cycles per conversion, with tCONV = 3.6µs in internal clock mode and scalable down to 2.1µs at 7.6MHz external clock. Input protection includes on-chip clamping diodes allowing ±300mV overvoltage tolerance, while COM pin stability (±0.5 LSB) is required during sampling for <±0.5 LSB INL performance.

Key Specifications

Pinout & Package

MAX1268BCEG+ is housed in a 24-pin QSOP (Quad Small Outline Package) with 0.15mm lead pitch and 7.6mm × 4.4mm body size - compatible with standard surface-mount reflow profiles and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1267BCEG+, MAX1268BCEG+ offers direct +5V compatibility and wider supply margin; versus ADS7822U, it delivers higher throughput, dual-channel capability, and integrated reference - making it optimal for space-constrained, battery-powered measurement systems needing minimal external components.

Availability

MAX1268BCEG+ is available at Aetrix Electronics and suitable for patient monitoring, industrial data logging, and energy management systems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for MAX1268BCEG+ 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 MAX126x family targets portable and space-constrained measurement systems requiring high-resolution ADCs with integrated references and minimal external components - specifically optimized for battery-operated data acquisition.

FAQ

What is the operating temperature range for MAX1268BCEG+?

The MAX1268BCEG+ is specified for 0°C to +70°C ambient operation, as indicated by the 'C' grade suffix in its ordering code. This commercial-grade temperature range is validated across all electrical parameters including INL (±0.5 LSB), supply current (2.8mA at 420ksps), and reference stability (±100mV REFADJ range). Industrial-grade alternatives like MAX1268BEEG extend to -40°C to +85°C but require separate qualification.

Does MAX1268BCEG+ support pseudo-differential input mode?

Yes, MAX1268BCEG+ supports pseudo-differential input mode via the SGL/DIF control bit (D4). When SGL/DIF = 0, it measures the voltage difference between CH0 (IN+) and CH1 (IN−), requiring COM to be stable within ±0.5 LSB. This mode rejects common-mode noise without needing external instrumentation amplifiers - confirmed in Tables 2 and 3 of the datasheet and functional diagram Figure 2.

Can MAX1268BCEG+ operate with an external reference voltage?

Yes, MAX1268BCEG+ supports external reference operation: tie REFADJ to VDD to disable the internal bandgap, then apply a stable 2.5V reference to the REF pin (bypassed with 4.7µF capacitor). External reference mode maintains full 12-bit resolution and ±0.5 LSB INL, but forfeits REFADJ trimming capability - verified in Electrical Characteristics Table and Pin Description section.

What is the minimum acquisition time required before conversion starts?

The minimum acquisition time (tACQ) for MAX1268BCEG+ is 400ns in internal clock mode, derived from the 3.6µs total conversion time minus 13 clock cycles at 7.6MHz. For external sources with >3kΩ impedance, tACQ increases per tACQ = 9(RS + 800Ω) × 12pF - requiring ≥1µs for 10kΩ sources. This value is explicitly listed in the Electrical Characteristics table under "T/H Acquisition Time".

How does the power-down functionality work on MAX1268BCEG+?

MAX1268BCEG+ implements two software-selectable power-down modes via PD1/PD0 bits (D7/D6): full power-down reduces supply current to <2µA by disabling the reference and T/H; standby mode cuts current to ~950µA while retaining reference bias. Both modes exit in 2µs upon CS/WR access - confirmed in General Description and Electrical Characteristics sections with measured IDD values across sampling rates.