Analog Devices Inc./Maxim Integrated MAX1247BCPE+

Overview

MAX1247BCPE+ from Maxim Integrated is a 12-bit serial analog-to-digital converter with integrated 4-channel multiplexer, track/hold, and SPI/QSPI/MICROWIRE-compatible interface. It operates from a single +2.7V to +5.25V supply, supports software-configurable unipolar/bipolar and single-ended/differential inputs, and delivers 133ksps conversion rate with 73dB SINAD at 10kHz. It is used in portable data loggers and battery-powered medical instruments requiring low-power, high-accuracy signal digitization.

For engineers reviewing the MAX1247BCPE+ datasheet, MAX1247BCPE+ pinout, MAX1247BCPE+ application, or MAX1247BCPE+ equivalent, key selection criteria include its external reference requirement, QSOP-16 package, ±1 LSB INL (max), 1.2mA active current at 133ksps, and shutdown current of 1µA - all critical for precision, power-constrained embedded sensing systems.

Technical Context

The MAX1247BCPE+ employs successive-approximation register (SAR) architecture with an internal track/hold circuit that acquires input signals in ≤1.5µs. Its analog front-end supports pseudo-differential sampling via CH0–CH3 and COM, with configurable input ranges (0V to VREF or ±VREF/2) and channel-to-channel offset matching of ±0.25 LSB.

It uses either an external serial clock (up to 2MHz) or internal clock (0.225MHz typical when SHDN = VDD) for conversion control. The 4-wire serial interface outputs MSB-first data on DOUT at SCLK falling edges and provides SSTRB strobe timing synchronized to conversion start/end - enabling direct interfacing with TMS320-family DSPs without glue logic.

Key Specifications

Pinout & Package

The MAX1247BCPE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm), occupying the same PCB footprint as an 8-pin SOIC - enabling compact, space-optimized layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131ETE+, the MAX1247BCPE+ uniquely combines integrated 4-channel MUX, track/hold, and external reference support in QSOP-16 - making it optimal for multi-sensor, battery-powered systems requiring design simplicity and supply flexibility.

Availability

MAX1247BCPE+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and guaranteed authentic sourcing.

Supply support for MAX1247BCPE+ 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 industrial, medical, and communications applications.

The MAX1247BCPE+ belongs to Maxim's low-power serial ADC product line, engineered for high-accuracy data acquisition in space- and energy-constrained embedded systems where integration, configurability, and supply flexibility are critical.

FAQ

What is the reference voltage requirement for MAX1247BCPE+?

The MAX1247BCPE+ requires an external reference voltage applied to the VREF pin, ranging from 1.0V to (VDD + 50mV). Unlike the MAX1246, it does not include an internal reference. The reference buffer must be disabled by connecting REFADJ to VDD. Typical operation uses a stable 2.500V reference to achieve specified INL and gain error performance. Reference input impedance is 18–25kΩ, and input current is 100–150µA at 2.5V.

Does MAX1247BCPE+ support differential input mode?

Yes, the MAX1247BCPE+ supports pseudo-differential input mode via software configuration. Setting SGL/DIF = 0 in the control byte selects differential operation, allowing CH0/CH1 or CH2/CH3 pairs to be measured as voltage differences. In this mode, the negative input (IN−) must remain stable within ±0.5 LSB relative to AGND during conversion. A 0.1µF capacitor from the selected IN− channel to AGND is recommended to maintain stability and accuracy.

What is the minimum acquisition time for MAX1247BCPE+?

The guaranteed minimum acquisition time (tACQ) for MAX1247BCPE+ is 1.5µs, defined as the maximum time required for the internal track/hold to settle after the last control bit is clocked. This value assumes source impedance ≤1kΩ. For higher impedances, tACQ increases per tACQ = 9 × (RS + 9kΩ) × 16pF. Exceeding the required acquisition window risks droop-induced code errors, especially at full-scale input transitions.

How does the SHDN pin function on MAX1247BCPE+?

The SHDN pin on MAX1247BCPE+ provides three distinct operating states: pulling SHDN low enables full power-down (1µA supply current); letting SHDN float configures the reference buffer for external compensation (requires 4.7µF at VREF); pulling SHDN high selects internal compensation mode. SHDN is not a simple on/off switch - its voltage level directly controls reference buffer topology and power state, enabling optimized trade-offs between accuracy, power, and external component count.

Can MAX1247BCPE+ interface directly with TMS320-family DSPs?

Yes, MAX1247BCPE+ can interface directly with TMS320-family DSPs using the SSTRB (serial strobe) output. In internal clock mode, SSTRB goes low at conversion start and high at completion; in external clock mode, it pulses high for one SCLK period before the MSB decision. This precise timing eliminates the need for polling or additional handshaking signals, enabling deterministic, low-latency data capture synchronized to the DSP's processing cycle.