Analog Devices Inc./Maxim Integrated MAX1249BCEE+

Overview

MAX1249BCEE+ from Maxim Integrated is a 10-bit, 4-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, and SPI/QSPI/MICROWIRE-compatible 4-wire interface. It operates from a single +2.7V to +5.25V supply, consumes only 54µA at 1ksps (+3V), and supports external reference input at VREF pin. It is used in portable data loggers and battery-powered medical instrumentation requiring low quiescent current and compact footprint.

For engineers reviewing the MAX1249BCEE+ datasheet, MAX1249BCEE+ pinout, MAX1249BCEE+ application, or MAX1249BCEE+ equivalent, this page delivers verified technical context, real-world timing and accuracy specs, QSOP-16 package details, and two validated alternative parts for design-in flexibility under low-power, multi-channel sampling constraints.

Technical Context

The MAX1249BCEE+ uses successive-approximation architecture with an internal track/hold circuit that acquires input signals in ≤1.5µs and completes conversion in 7.5µs (internal clock mode) or 15 SCLK cycles (external clock mode). Its analog front-end supports pseudo-differential operation across CH0–CH3 with COM as common-mode reference, and accepts external 2.500V reference voltage at the VREF pin with ±1.5% adjustment range via REFADJ.

Digital control is implemented through an 8-bit command byte (START, SEL2–SEL0, UNI/BIP, SGL/DIF, PD1/PD0) that configures channel selection, input polarity, input type, and clock/power-down mode. The device features three-level SHDN control (low = full shutdown, high = internal compensation, float = external compensation) and provides SSTRB strobe output synchronized to conversion start/end for TMS320-family DSP interfacing.

Key Specifications

Pinout & Package

MAX1249BCEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm), occupying the same PCB area as an 8-pin SOIC - enabling space-constrained upgrades from legacy 8-pin ADCs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit, serial, low-power ADC applications.

Compared with ADS7822U and MAX11100ETE+, the MAX1249BCEE+ uniquely balances 10-bit precision, external reference flexibility, 3-level shutdown, and multi-protocol serial compatibility in a legacy-compatible QSOP-16 package - making it optimal for cost-sensitive, battery-operated, and space-constrained industrial measurement designs.

Availability

MAX1249BCEE+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered instruments requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX1249BCEE+ 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 fabless semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications markets.

The MAX1248/MAX1249 family was designed specifically for low-power, multi-channel data acquisition in portable and remote sensing applications - emphasizing minimal supply current, flexible input configuration, and seamless µP interfacing without external components.

FAQ

What is the reference voltage configuration for MAX1249BCEE+?

The MAX1249BCEE+ requires an external reference voltage applied to the VREF pin, typically 2.500V ±0.030V. Unlike the MAX1248, it does not include an internal reference buffer. The REFADJ pin must be tied to VDD to disable the internal buffer, ensuring accurate external reference operation. This configuration reduces power consumption and improves PSR to ±0.3mV.

Does MAX1249BCEE+ support differential input mode?

Yes, the MAX1249BCEE+ supports pseudo-differential input mode by selecting CH0/CH1 or CH2/CH3 pairs using the SEL2–SEL0 and SGL/DIF bits in the control byte. In this mode, the device samples the voltage difference |IN+ − IN−|, with IN− held stable to ±0.5LSB. A 0.1µF capacitor from the selected IN− channel to AGND is required to maintain accuracy.

What is the minimum acquisition time for MAX1249BCEE+?

The MAX1249BCEE+ has a guaranteed maximum acquisition time (tACQ) of 1.5µs, defined as the time needed for the track/hold circuit to settle after the last control bit is clocked in. This value assumes source impedance ≤3kΩ. For higher impedances, tACQ increases per tACQ = 7.6 × (RS + 9kΩ) × 16pF, requiring additional inter-conversion delay to prevent droop-induced errors.

How does the SHDN pin function on MAX1249BCEE+?

The SHDN pin on MAX1249BCEE+ provides three-level control: pulled low → full shutdown (1µA); pulled high → internal reference buffer compensation enabled; left floating → external reference compensation enabled. This allows precise power-state management without external logic, and automatic wake-up occurs on any SCLK or CS activity.

Is MAX1249BCEE+ compatible with TMS320-family DSPs?

Yes, the MAX1249BCEE+ includes a dedicated SSTRB (serial strobe) output that synchronizes directly with TMS320-family DSPs. In internal clock mode, SSTRB goes low at conversion start and high at completion; in external mode, it pulses high for one SCLK period before the MSB appears on DOUT - enabling precise DMA-triggered data capture without CPU intervention.